EP3036100A1 - Blank, in particular for permanently closing holes - Google Patents

Abstract

The invention relates to a blank (1), in particular for permanently closing holes in metal sheets or plastic parts, said blank comprising a carrier made of a laminate consisting of at least two plastic films (2, 3), wherein the lower film (3) has a weight per unit area of at least 1.5 kg/m2, and an adhesive mass (4), in particular an adhesive mass that can be hardened or is self-adhesive, is applied to the side of the lower film facing away from the upper film (2).

Description

 description

Punching in particular for the permanent closing of holes

The present invention relates to a stamped product, in particular for permanently sealing holes, which are preferably located in sheets or in plastic parts, as well as a method for permanently closing holes.

In the production of more complex structures made of metal sheets and / or plastics, it is structurally unavoidable that holes have to be cut into the sheets or plastics in order to reach cavities behind them, be it for painting or for welding.

These holes are after the completion of the desired process usually no longer necessary, often even disturbing, because through them air, humidity or water can penetrate into the structure, which for example can lead to oxidation processes (rust).

 A simple solution to avoid these problems is to reseal the holes after use.

Especially in the production of modern vehicles such as watercraft, land vehicles (trucks, automobiles, etc.), aircraft, spacecraft, combinations thereof, for example, amphibious vehicles, it is inevitable that during assembly in many individual parts of sheets or plastics different sized holes required are. Usually, the diameters of the holes are between 5 and 50 mm. Many of these holes must be re-air and in particular watertight sealed in the later process to prevent said Korrossionsangriffe. In addition, there is a requirement to significantly improve the noise insulation of the passenger compartment by closing the holes.

In the following, the problems underlying the invention and their solution will be described using the example of the body of an automobile. This expressly does not limit the inventive idea to this application. This application forms part of the technical field in which the invention is particularly advantageous.

 If from now on the use is called in a body, the expert reads all other applications outside of a body.

In the automotive industry, holes must be set or punched out at various points in the bodywork. As a rule, this is done during the stamping and forming process of the individual sheet metal or aluminum parts, and holes can also be drilled in plastic components. Subsequently, the individual metal parts are connected to each other by means of various joining processes, and the body shell is created. The holes, openings or openings therein serve, among other things, as paint drainage holes (for example for cathodic dip paint), wax injection holes, wax drainage holes, holes for subsequent screwing in the assembly or for cable bushings. Many of these holes need to be resealed after drying the cathodic dip or even after the final clear coat process (then the pinhole would take place in the assembly process).

The need for a hole closure can have many causes, for example: - Moisture

 acoustics

 corrosion protection

As a rule, the holes or openings are closed by means of injection-molded parts (plugs) made of various plastics, which are manufactured according to the requirements. These can be, for example, stoppers made of PET, ABS, PP, PVC, EPDM, PA and other common plastics on the market or even combinations of the materials mentioned and commercially customary plastic substrates not listed here. In use, there are also materials that have a share of glass fibers; Also conceivable are carbon fibers, which reinforce the plug against, for example to provide the puncture. Basically, all common plastic substrates are possible, as long as they offer certain parameters for paintability, temperature stability, dimensional stability under climatic conditions and also fulfill a certain economy in the production process of the plug.

Currently, plastic plugs are usually used for closing body holes, which are not sure to close the hole on the one hand in an individual case and on the other hand are comparatively complex and expensive to produce. For each hole size, a special, adapted to the hole size plug is required. This means high logistical and administrative effort for the customer of the plug.

 For example, a large number of plugs of different sizes must be kept in the respective assigned storage boxes on the production line. Furthermore, adhesive tapes which are cut to length or punched to fit the hole size are suitable for this purpose. But also tapes do not always meet the increasing demands in the market.

As already described in WO 2006/053827 A1, die-cuts are also suitable for the special perforated closure, which consist of a heat-resistant carrier at least partially self-adhesive base layer whose area is greater than the area of the hole to be closed and in particular is provided centrally on the adhesive side equipped with a first portion of a heat-activatable adhesive film whose area is greater than the area of the hole to be closed and smaller than the surface of the base layer. The blank is applied over the hole to be closed so that the hole is substantially covered by the first portion. The described heat-activatable adhesive films are well suited for sealing, but are relatively expensive. The possibility of introducing a component into the stamped article which completely fills and / or covers the hole at elevated temperature, such as a drying step in the painting area, by foaming, is described in WO 2005/097582 A1. However, it is found that the unfoamed component must have a large expansion in order to ensure a complete hole closure, since the propagation direction only through the adhesion side to one-sided self-adhesive Stanzling is limited. Due to this necessary high degree of foaming, the resulting hole closure has only a comparatively low material density, which has a disadvantageous effect on the noise-damping properties. In addition, such a hole closure shows only a low strength in terms of foam adhesion to the sheet, since the material comes into contact only with the hole edge and little sheet on the side facing away from the stamped part. This results in a low puncture resistance, which is of crucial importance for the described application.

Here, the self-adhesive hole closures, which must achieve an acoustic effect, are considered closer.

Often these acoustically relevant hole closures are used in the assembly in order to achieve a foreclosed area in the passenger compartment, the vehicle interior. A disturbing in the vehicle interior acoustics is generated for example by rolling noise of the tires or by rolling chips and small stones that are thrown against the Fahrzeugbeplankung and also against the vehicle carrier. Further wind noise, which may be due to aerodynamically unfavorable design, may be a cause of higher, undesirable noise level in the passenger compartment.

Often caused by rolling chips, pebbles, rolling noise of the tires and also by uneven floors sound in the cavities of the carrier systems (longitudinal and cross member) in the vehicle interior or the passenger compartment forwarded. This means that acoustically effective products must also be used outside the vehicle. For example, effective acoustic protection is to mask holes in the underbody or in the vehicle platform. Often holes, punched holes or holes in the longitudinal and transverse beams are introduced. Here, special care must be taken to ensure that every possible opening is carefully closed.

As already described above, many holes in the body panels, or the carrier systems serve to allow the KTL paint as quickly as possible from the body and all kinds of cavities can run to secure process time. Conversely, this means that immediately after the KTL T rockner the openings and holes must be securely closed. In general, this will be in the so-called PVC line completed. This area is a production step which takes place before the filler painting or before the basecoat painting. Thus, another feature to be met is the recoatability of products used in this production section. Furthermore, compatibility with PVC seam sealing material has to be ensured, as gaps between pumpable PVC masses are sealed between the cathodic dryers and the next layer of varnish.

The object of the invention is to provide a stamped product which is suitable for permanently sealing holes, in particular in sheets or in plastic parts of automobile bodies, which closes said holes in such a way that a passage of moisture is eliminated, which improves the noise insulation and the the holes even with rockfall on the subfloor or mechanical stresses in the interior, especially in the bottom area, safely closes.

This problem is solved by a diecut, as laid down in the main claim. Subject of the dependent claims are advantageous developments of the subject invention and a method for permanently closing holes.

Accordingly, the invention relates to a stamped product, in particular for permanently sealing holes, in particular in sheets or in plastic parts with a carrier made of a laminate of at least two plastic films, wherein the lower film has a basis weight of at least 1, 5 kg / m ² and on the upper Foil opposite side of the lower film, an adhesive, in particular curable or self-adhesive adhesive is applied.

According to a preferred embodiment of the invention, the lower film has a basis weight between 1, 5 and 6 kg / m ² , preferably between 1, 5 and 3.9 kg / m ² between 1, 5 and 2.5 kg / m ² . The lower film is preferably a heavy film such as a polyolefin film filled in particular with mineral or an elastomer-modified bituminous film.

 Possible production variants of such a heavy foil are extrusion processes or

Casting processes.

A heavy foil consists of a foil-like layer of any thickness, in particular from 0.015 mm to over 12 mm, wherein the heavy foil in particular of thermoplastic polymers, in particular PE (polyethylene), EPDM (ethylene-propylene-diene rubber) and / or EVA (ethylene-vinyl acetate ) and mineral fillers, in particular limestone powder or calcite (CaC0 ₃ ) and heavy spar (BaS0 ₄ ) composed. Furthermore, for filling talc, slate, graphite, mica or asbestos (the latter today rather less) can be used.

The proportion of fillers is in particular 30 to 90 wt .-%, preferably 40 to 70 wt .-%.

 Expressed in percent by volume, the proportion is preferably from 30 to 60% by volume, more preferably from 45 to 55% by volume,

The heavy foil may additionally contain oil for swelling and for better absorption of the fillers. The oil content can be between 8 vol.% To 20 vol.%.

Instead of an upper foil, a stampable aluminum sheet, a corrosion resistant steel sheet or an aluminum foil with a scrim for reinforcement or strength may be laminated on the lower sheet.

The top film may be any polymer, either alone or in admixture.

 Suitable polymers are olefinic polymers such as homo- or copolymers of olefins such as ethylene, propylene or butylene (the term copolymer is to be understood as meaning herein terpolymers), polypropylene homopolymers or polypropylene copolymers including the block (impact) and random polymers.

Other polymers can be selected from the group of polyesters such as in particular polyethylene terephthalate (PET), polyamides, polyurethanes, polyoxymethylene, polyvinyl chloride (PVC), polyethylene naphthalate (PEN), ethylene vinyl alcohol (EVOH), Polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polycarbonate (PC), polyamide (PA), polyethersulfone (PES), polyimide (PI), polyarylene sulfides and / or polyarylene oxides.

 These polymers, alone or in mixture, are also suitable for forming the heavy film.

The upper film preferably consists of polyester (in particular of polyethylene terephthalate (PET)), polyurethane or PVC.

The polymers for forming the top film and the bottom film may be in pure form or in blends with additives such as antioxidants, sunscreens, antiblocking agents, lubricants and processing aids, fillers, dyes, pigments, blowing or nucleating agents.

 Preferably, the films have none of the additives mentioned. According to a further embodiment, the carrier may also have more than two foils. In particular, the upper carrier foil can consist of an at least two-layer laminate of two or more foil layers of any desired material (for example polyethylene, polypropylene, polyester, PA and / or PVC). In an advantageous embodiment of the invention, a layered body is present in the carrier (between the upper and the lower film) or on the carrier, which consists of metal, of a metal foil, for example aluminum foil, or of a metal-containing film. According to a preferred embodiment, the thickness of the upper film between 15 and 350 μηη, preferably between 30 and 200 μηη, more preferably between 50 and 150 μηι.

According to a preferred embodiment, the thickness of the lower film is between 600 and 3500 μηη, preferably between 1100 and 3500 μηη, more preferably between 1700 and 3500 μηη.

According to a further preferred embodiment, the thickness of the lower film is between 600 and 1100 μηι, between 1100 and 1700 μηη or between 1700 and 3500 μηι. In a further advantageous embodiment of the invention, the upper and / or lower film are reinforced by integrated or attached fibers or filaments, so that their strength is particularly reinforced in the longitudinal direction. For the purposes of this invention, a filament is understood to mean a bundle of parallel, straight individual fibers, often referred to in the literature as multifilament. Optionally, this fiber bundle can be solidified by twisting, then one speaks of spun or twisted filaments. Alternatively, the fiber bundle can be solidified by swirling with compressed air or water jet. In addition, for all these embodiments - as well as for the embodiment reinforced with fibers - generally only the term filament is used.

If a film is reinforced only by longitudinally integrated / attached filaments, it is called monofilament adhesive tapes. In an advantageous development of the subject invention, the upper film and / or the lower film are reinforced by an open filament fabric. In this case, it is called cross-filament tape.

As filaments high-strength fibers, twisted yarns, mixed yarns or threads with low elongation at break are added.

The individual filaments are preferably continuous filaments and / or have a fineness between 4 and 8 dtex, preferably 5 dtex. In an advantageous embodiment, all filaments are endless filaments.

In a preferred embodiment, there are between 1 and 30 filaments per centimeter width in the substrate, more preferably between 1 and 5.

The filaments can consist of organic or inorganic materials, for example and preferably glass, carbon, combinations of both types of fibers, aramid fibers or special polyamides, drawn polymer fibers such as polyester fibers, polypropylene fibers, polyethylene fibers, furthermore, the reinforcing fibers may be at least partially colored be to make the substrate more visually appealing. In this way it is easily possible to visually differentiate the reinforced carrier. Dyed glass or polymer threads are particularly suitable for this purpose. The film (s) are further preferably laminated with the filaments. The filaments should be firmly bonded to the film (s). This can be done by direct incorporation or incorporation of the fibers, threads or threads or mixed threads in the film (s), for example weaving in fabrics, knitting in knitted fabrics, embedding or insertion in the production process.

However, the filaments can also be subsequently connected to the film (s); for example, welding or lamination with a corresponding bonding layer may be mentioned.

Furthermore, the reinforcements are preferably inserted selectively in accordance with the direction of loading of the carrier, that is to say primarily in the longitudinal direction. However, they may also, if more appropriate, additionally in transverse or oblique direction or, for example, curved, spiral or zigzag-shaped or run randomly.

According to the invention, the curable adhesive used in an inventive variant is a structural adhesive (construction adhesive, assembly adhesive) (see Römpp, Georg Thieme Verlag, document identifier RD-19-04489, last update: September 2012). According to DIN EN 923: 2006-01, structural adhesives are adhesives that form adhesive bonds that can maintain a specified strength in a microstructure for a predetermined, longer period of time (according to the ASTM definition: bonding agents used for transferring required loads between adherends exposed to service environments typical for the structure involved ") These are adhesives for bonds which are chemically and physically highly stressable and which, when cured, contribute to the bonding of bonded substrates and are used to produce structures made of metals, ceramics, concrete, wood or reinforced plastics Structural adhesives according to the invention are based in particular on (thermosetting) reaction adhesives (phenolic resins, epoxy resins, polyimides, polyurethanes and others). The curable adhesive may be elastic after curing to ensure a durable, insensitive to vibration and twisting closure. According to an advantageous embodiment of the invention, the curable adhesive is self-adhesive, or at least partially a self-adhesive composition is applied to the curable adhesive.

Useful adhesive compositions include, in particular, reactive heat-activable adhesives.

 These have a very good dimensional stability when the elastomeric component has a high elasticity. Furthermore, the reactive resins require that a crosslinking reaction can occur, which significantly increases the bond strength. Thus, for example, heat-activatable adhesives based on nitrile rubbers and phenolic resins can be used, for example commercially available in product 8401 from tesa.

According to an advantageous embodiment, the adhesive consists at least of a) a polyamide having amino and / or acid end groups,

b) an epoxy resin,

c) optionally a plasticizer,

wherein the polyamide reacts at temperatures of at least 150 ° C with the epoxy resin and the ratio in parts by weight of a) and b) is between 50:50 to 99: 1.

More preferably, the adhesive is made

i) a thermoplastic polymer in a proportion of 30 to 89.9 wt .-%, ii) one or more tackifying resins in a proportion of 5 to 50 wt.% And / or

iii) epoxy resins with hardeners, optionally also accelerators, in a proportion of 5 to 40 wt .-%.

This adhesive is a blend of reactive resins that crosslink at room temperature to form a three-dimensional, high-strength polymer network, and permanently elastic elastomers that resist embrittlement of the product. The elastomer may preferably be selected from the group of polyolefins, polyesters, polyurethanes or polyamides or a modified rubber such as nitrile rubber.

 The particularly preferred thermoplastic polyurethanes (TPU) are known as reaction products of polyester or polyether polyols and organic diisocyanates such as diphenylmethane diisocyanate. They are composed of predominantly linear macromolecules. Such products are usually commercially available in the form of elastic granules, for example from Bayer AG under the trade name "Desmocoll".

 By combining TPU with selected compatible resins, the softening temperature of the adhesive can be lowered. In parallel, there is even an increase in adhesion. As suitable resins, for example, certain rosin, hydrocarbon and coumarone resins have been found.

 Alternatively, the reduction of the softening temperature of the adhesive can be achieved by combining TPU with selected epoxy resins based on bisphenol A and / or F and a latent curing agent. An adhesive from such a system allows a post-curing of the bondline, either gradually at room temperature without any further external intervention or for a short time by a targeted tempering.

 Due to the chemical crosslinking reaction of the resins, high strengths are achieved between the adhesive and the surface to be bonded and a high internal strength of the product is achieved.

 The addition of these reactive resin / hardener systems also leads to a lowering of the softening temperature of the above-mentioned polymers, which advantageously lowers their processing temperature and speed. The suitable product is a self-adhesive product at room or slightly elevated temperatures. When the product is heated, it also reduces the viscosity in the short term, allowing the product to wet even rough surfaces.

The compositions for the adhesive can be widely varied by changing the nature and content of the raw material. Likewise, further product properties such as color, thermal or electrical conductivity can be achieved by targeted additions of dyes, mineral or organic fillers and / or carbon or metal powders.

In particular, all acrylonitrile-butadiene copolymers having an acrylonitrile content of 15 can be used as nitrile rubbers in adhesives of the invention to 50% by weight. Likewise, copolymers of acrylonitrile, butadiene and isoprene can be used. The proportion of 1, 2-linked butadiene is variable. The aforementioned polymers can be hydrogenated to a different degree and fully hydrogenated polymers having a double bond content of less than 1% can be used.

All of these nitrile rubbers are carboxylated to a certain extent; the proportion of the acid groups is preferably from 2 to 15% by weight. Commercially, such systems are available, for example, under the name Nipol 1072 or Nipol NX 775 from Zeon. Hydrogenated carboxylated nitrile rubbers are commercially available under the name Therban XT VP KA 8889 from Lanxess.

In order to increase the adhesion, the addition of adhesive resins compatible with the nitrile rubbers is also possible. Epoxy resins are usually understood as meaning both monomeric and oligomeric compounds having more than one epoxide group per molecule. These may be reaction products of glycidic esters or epichlorohydrin with bisphenol A or bisphenol F or mixtures of these two. It is also possible to use epoxy novolak resins obtained by reaction of epichlorohydrin with the reaction product of phenols and formaldehyde. Also, monomeric compounds having multiple epoxide end groups used as thinners for epoxy resins are useful. Also elastically modified epoxy resins can be used.

Examples of epoxy resins are Araldite ™ 6010, CY-281 ™, ECN ™ 1273, ECN ™ 1280, MY 720, RD-2 from Ciba Geigy, DER ™ 331, 732, 736, DEN ™ 432 from Dow Chemicals, Epon ™ 812, 825, 826, 828, 830 etc. from Shell Chemicals, HPT ™ 1071, 1079 also from Shell Chemicals, Bakelite ™ EPR 161, 166, 172, 191, 194 etc. from Bakelite AG.

Commercial aliphatic epoxy resins are, for example, vinylcyclohexane dioxides such as ERL-4206, 4221, 4201, 4289 or 0400 from Union Carbide Corp.

Elastified epoxy resins are available from Noveon under the name Hycar.

Epoxy diluents, monomeric compounds having a plurality of epoxide groups are, for example, Bakelite ™ EPD KR, EPD Z8, EPD HD, EPD WF from Bakelite AG or Polypox ™ R 9, R12, R 15, R 19, R 20 from UCCP. More preferably, the adhesive contains more than one epoxy resin.

As novolac resins, for example, Epi-Rez ™ 5132 from Celanese, ESCN-001 from Sumitomo Chemical, CY-281 from Ciba Geigy, DEN ™ 431, DEN ™ 438, Quatrex 5010 from Dow Chemical, RE 305S from Nippon can be used Kayaku, Epiclon ™ N673 from DaiNipon Ink Chemistry or Epicote ™ 152 from Shell Chemical.

Furthermore, melamine resins such as Cymel ™ 327 and 323 from Cytec can also be used as reactive resins.

Furthermore, reactive resins can also be used for terpene phenolic resins such as, for example, NI REZ ™ 2019 from Arizona Chemical. Furthermore, as reactive resins and phenolic resins such as YP 50 from Toto Kasei, PKHC Union Carbide Corp. can be. and BKR 2620 from Showa Union Gosei Corp. deploy.

 Furthermore, phenolic resole resins can also be used as reactive resins in combination with other phenolic resins.

It is also possible to use as reactive resins polyisocyanates such as Coronate ™ L from Nippon Polyurethane Ind., Desmodur ™ N3300 or Mondur ™ 489 from Bayer. In an advantageous embodiment of the adhesive based on nitrile rubber according to the invention, adhesive-increasing (tackifying) resins are also added; very advantageous to a proportion of up to 30 wt .-%, based on the adhesive.

As tackifying resins to be added, all previously known adhesive resins described in the literature can be used without exception. Non-hydrogenated, partially or completely hydrogenated resins based on indene, rosin and rosin derivatives, hydrogenated polymers of dicyclopentadiene, non-hydrogenated, partially, selectively or completely hydrogenated hydrocarbon resins based on C ₅ -, C ₅ / C ₉ are particularly suitable, inter alia or Cg monomer streams, terpene phenolic resins, terpene resins based on α-pinene and / or β-pinene and / or δ-limonene or hydrogenated polymers preferably pure C ₈ and C ₉ aromatics, aromatic resins such as cumarone-indene resins or resins of styrene or α-methylstyrene such as rosin and its derivatives such as disproportionated, dimerized or esterified resins, glycols, glycerol or pentaerythritol.

Any combination of these and other resins can be used to adjust the properties of the resulting adhesive as desired. In general, all compatible with the corresponding polymer (soluble) resins can be used. The presentation of the state of knowledge in the "Handbook of Pressure Sensitive Adhesive Technology" by Donatas Satas (van Nostrand, 1989) is expressly pointed out.

In addition to the acid or acid anhydride modified nitrile rubbers already mentioned, other elastomers can also be used. In addition to other acid- or acid anhydride-modified elastomers, it is also possible to use unmodified elastomers, for example polyvinyl alcohol, polyvinyl acetate, styrene block copolymers, polyvinyl formal, polyvinyl butyral or soluble polyesters.

 It is also possible to use copolymers with maleic anhydride, for example a copolymer of polyvinyl methyl ether and maleic anhydride, for example available under the name Gantrez ™, marketed by ISP.

Due to the chemical crosslinking of the resins with the elastomers, very high strengths are achieved within the adhesive.

As further additives can typically be used:

Primary antioxidants such as sterically hindered phenols

 secondary antioxidants such as phosphites or thioethers

 Process stabilizers such as C radical scavengers

 Light stabilizers such as UV absorbers or hindered amine processing aids

Fillers such as silica, glass (milled or in the form of spheres), aluminas, zinc oxides, calcium carbonates, titanium dioxides, carbon blacks, metal powders, etc.

Color pigments and dyes as well as optical brighteners By using plasticizers, the elasticity of the crosslinked adhesive can be increased. Plasticizers which may be used are, for example, low molecular weight polyisoprenes, polybutadienes, polyisobutylenes or polyethylene glycols and polypropylene glycols or plasticizers based on polyethylene oxides, phosphate esters, aliphatic carboxylic acid esters and benzoic acid esters. Furthermore, it is also possible to use aromatic carboxylic esters, relatively high molecular weight diols, sulfonamides and adipic esters.

Since the nitrile rubbers used do not have too low a viscosity even at high temperatures, the adhesive does not escape from the adhesive joint during gluing and hot pressing. During this process, the epoxy resins crosslink with the elastomers, resulting in a three-dimensional network.

By adding so-called accelerators, the reaction rate can be further increased.

 Accelerators can be for example:

 tertiary amines such as benzyldimethylamine, dimethylaminomethylphenol, tris (dimethylaminomethyl) phenol

 Boron trihalide-amine complex

- substituted imidazoles

 triphenylphosphine

 For example, imidazoles commercially available as 2M7, 2E4MN, 2PZ-CN, 2PZ-CNS, PO550, L07N from Shikoku Chem. Corp. are suitable as accelerators. or Curezol 2MZ from Air Products. Further suitable crosslinkers are HMTA (hexamethylenetetramine) additives.

Furthermore, optional fillers (for example fibers, carbon black, zinc oxide, titanium dioxide, chalk, solid or hollow glass spheres, microspheres of other materials, silicic acid, silicates), nucleating agents, blowing agents, adhesive-enhancing additives and thermoplastics, compounding agents and / or aging inhibitors, for example in Form of primary and secondary antioxidants or in the form of sunscreens.

In a further preferred embodiment, further additives are added to the adhesive, for example polyvinylformal, polyacrylate rubbers, chloroprene Rubbers, ethylene-propylene-diene rubbers, methyl-vinyl-silicone rubbers, fluorosilicone rubbers, tetrafluoroethylene-propylene copolymer rubbers, butyl rubbers, styrene-butadiene rubbers.

 Polyvinyl butyrals are available as Butvar ™ from Solucia, under Pioloform ™ from Wacker and under Mowital ™ from Kuraray. Polyacrylate rubbers are available under Nipol AR ™ from Zeon. Chloroprene rubbers are available under Baypren ™ from Bayer. Ethylene-propylene-diene rubbers are available under Keltan ™ from DSM, under Vistalon ™ from Exxon Mobile and under Buna EP ™ from Bayer. Methyl vinyl silicone rubbers are available from Silastic ™ from Dow Corning and Silopren ™ from GE Silicones. Fluo silicone rubbers are available as Silastic ™ from GE Silicones. Butyl rubbers are available on Esso Butyl ™ from Exxon Mobile. Styrene-butadiene rubbers are available as Buna S ™ from Bayer, and Europrene ™ from Eni Chem and under Polysar S ™ from Bayer.

 Polyvinylformals are available on Formvar ™ from Ladd Research.

In a further preferred embodiment, further additives are added to the adhesive, for example thermoplastic materials from the group of the following polymers: polyurethanes, polystyrene, acrylonitrile-butadiene-styrene terpolymers, polyesters, hard polyvinyl chlorides, flexible polyvinyl chlorides, polyoxymethylenes, polybutylene terephthalates, Polycarbonates, fluorinated polymers such as polytetrafluoroethylene, polyamides, ethylene-vinyl acetates, polyvinyl acetates, polyimides, polyethers, copolyamides, copolyesters, polyolefins such as polyethylene, polypropylene, polybutene, polyisobutene and poly (meth) acrylates. The bond strength of the heat-activatable adhesive can be counteracted by further targeted addition of additives. Thus, for example, polyimine or polyvinyl acetate copolymers can also be used as adhesion-promoting additives.

In a further preferred variant, the adhesive applied to the carrier is a pressure-sensitive adhesive, that is to say an adhesive which, even under relatively weak pressure, permits a lasting connection with almost all adhesive properties and can be removed from the primer again without leaving any residue after use. A PSA is permanently tacky at room temperature, so it has a sufficiently low viscosity and high tack, so that it wets the surface of the respective Klebegrunds already at low pressure. The Adhesiveness of the adhesive is based on its adhesive properties and the removability on its cohesive properties.

It can be used on all known adhesive systems. In addition to natural or synthetic rubber-based adhesives, it is possible in particular to use silicone adhesives and also polyacrylate adhesives, preferably a low molecular weight acrylate hot melt pressure-sensitive adhesive.

Preference is given to adhesives based on acrylate or silicone.

The adhesive can be selected from the group of natural rubbers or synthetic rubbers or from any blend of natural rubbers and / or synthetic rubbers, the natural rubber or natural rubbers basically being made of all available qualities such as Crepe, RSS, ADS, TSR. or CV types, depending on the required level of purity and viscosity, and the synthetic rubber or synthetic rubbers from the group of random copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), the synthetic polyisoprenes (IR), the Butyl rubbers (NR), the halogenated butyl rubbers (XI IR), the acrylate rubbers (ACM), the ethylene-vinyl acetate copolymers (EVA) and the polyurethanes and / or their blends can be selected.

Further, it is preferable to add to the rubbers, for the purpose of improving the processability, thermoplastic elastomers having a weight proportion of 10 to 50% by weight, based on the total elastomer content.

By way of example, the particularly compatible styrene-isoprene-styrene (SIS) and styrene-butadiene-styrene (SBS) types may be mentioned as examples. Suitable elastomers for blending are also, for example, EPDM or EPM rubber, polyisobutylene, butyl rubber, ethylene-vinyl acetate, hydrogenated block copolymers of dienes (for example by hydrogenation of SBR, cSBR, BAN, NBR, SBS, SIS or IR, such polymers for example known as SEPS and SEBS) or acrylate copolymers such as ACM.

In addition, a 100% system based on styrene-isoprene-styrene (SIS) has proven suitable. Crosslinking is advantageous for improving the redetachability of the adhesive tape after use and may be thermal or by exposure to UV light or electron beams.

 For the purpose of thermally induced chemical crosslinking are all known thermally activatable chemical crosslinkers such as accelerated sulfur or sulfur donor systems, isocyanate systems, reactive melamine, formaldehyde and (optionally halogenated) phenol-formaldehyde resins or reactive phenolic or Diisocyanatvernetzungssysteme with the corresponding activators, epoxidized polyester - And acrylate resins and their combinations used.

The crosslinkers are preferably activated at temperatures above 50 ° C, in particular at temperatures of 100 ° C to 160 ° C, most preferably at temperatures of 1 10 ° C to 140 ° C.

 The thermal excitation of the crosslinker can also be effected by IR radiation or high-energy alternating fields.

Suitable adhesives are solvent-based, water-based or even as a hot-melt system. A composition based on acrylate hotmelt is also suitable, it being possible for it to have a K value of at least 20, in particular greater than 30, obtainable by concentrating a solution of such a composition into a system which can be processed as a hotmelt

 The concentration can take place in suitably equipped boilers or extruders, in particular in the concomitant degassing a vented extruder is preferred.

 Such an adhesive is set forth in DE 43 13 008 A1, the content of which is hereby incorporated by reference and the content of which is part of this disclosure and invention. The adhesive on Acrylathotmelt-based but can also be chemically crosslinked.

In a further embodiment, self-adhesives used are copolymers of (meth) acrylic acid and their esters having 1 to 25 C atoms, maleic, fumaric and / or itaconic acid and / or their esters, substituted (meth) acrylamides, maleic anhydride and other vinyl compounds, such as vinyl esters, in particular vinyl acetate, vinyl alcohols and / or vinyl ethers used.

The residual solvent content should be below 1% by weight. An adhesive which also shows to be suitable is a low molecular weight acrylate hot melt pressure-sensitive adhesive, such as that supplied by BASF under the name acResin UV or Acronal®, in particular Acronal® DS 3458 or AC Resin A 260UV. This adhesive with a low K value obtains its application-oriented properties through a final radiation-induced crosslinking.

Finally, it should be mentioned that polyurethane-based adhesives are also suitable.

To optimize the properties, the self-adhesive composition used can be blended with one or more additives, such as tackifiers (resins), plasticizers, fillers, pigments, UV absorbers, light stabilizers, aging inhibitors, crosslinking agents, crosslinking promoters or elastomers.

Tackifiers are the resins already described in detail.

Suitable fillers and pigments are, for example, carbon black, titanium dioxide, calcium carbonate, zinc carbonate, zinc oxide, silicates or silicic acid.

Suitable plasticizers are, for example, aliphatic, cycloaliphatic and aromatic mineral oils, di- or poly-esters of phthalic acid, trimellitic acid or adipic acid, liquid rubbers (for example nitrile or polyisoprene rubbers), liquid polymers of butene and / or isobutene, acrylic esters, polyvinyl ethers, liquid and soft resins based on the raw materials to adhesive resins, wool wax and other waxes or liquid silicones.

Crosslinking agents are, for example, phenolic resins or halogenated phenolic resins, melamine and formaldehyde resins. Suitable crosslinking promoters are, for example, maleimides, allyl esters, such as triallyl cyanurate, polyfunctional esters of acrylic and methacrylic acid.

A "poly (meth) acrylate" is understood as meaning a polymer whose monomer base consists of at least 60% by weight of acrylic acid, methacrylic acid, acrylic acid esters and / or methacrylic acid esters, acrylic esters and / or methacrylates being at least partly, preferably at least 50% by weight. %, based on the total monomer base of the polymer in question a "poly (meth) acrylate" means a polymer which is obtainable by radical polymerization of acrylic and / or methacrylic monomers and optionally other copolymerizable monomers According to the invention, the poly (meth) acrylate or poly (meth) acrylates are from 30 to Preferably, the PSA according to the invention contains from 35 to 55% by weight, based on the total weight of the PSA, of at least one poly (meth) acrylate. Meth) acrylate is preferably <0 ° C, more preferably between -20 and -50 ° C.

The glass transition temperature of polymers or polymer blocks in block copolymers is determined in the context of this invention by means of dynamic scanning calorimetry (DSC).

The poly (meth) acrylates of the PSA of the invention are preferably obtainable by at least partial incorporation of functional monomers which are preferably crosslinkable with epoxide groups. Particular preference is given to monomers having acid groups (especially carboxylic acid, sulfonic acid or phosphonic acid groups) and / or hydroxyl groups and / or acid anhydride groups and / or epoxide groups and / or amine groups; particular preference is given to monomers containing carboxylic acid groups. It is particularly advantageous if the polyacrylate comprises copolymerized acrylic acid and / or methacrylic acid. All of these groups have a crosslinking ability with epoxide groups, whereby the polyacrylate is advantageously accessible to thermal crosslinking with incorporated epoxides.

Other monomers which can be used as comonomers for the poly (meth) acrylates, in addition to acrylic acid and / or methacrylic acid esters having up to 30 carbon atoms per molecule, for example vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinyl aromatic compounds with up to 20 C atoms, ethylenically unsaturated nitriles, vinyl halides, vinyl ethers of alcohols containing 1 to 10 carbon atoms, aliphatic hydrocarbons having 2 to 8 carbon atoms and one or two double bonds or mixtures of these monomers. The properties of the relevant poly (meth) acrylate can be influenced in particular by varying the glass transition temperature of the polymer by different weight proportions of the individual monomers. The poly (meth) acrylate (s) of the invention may preferably be recycled to the following monomer composition: a) acrylic acid esters and / or methacrylic acid esters of the following formula

CH ₂ = C (R ') (COOR ")

where R ¹ = H or CH ₃ and R "is an alkyl radical having 4 to 14 C atoms,

b) olefinically unsaturated monomers having functional groups already defined for reactivity with epoxide groups,

c) optionally further acrylates and / or methacrylates and / or olefinically unsaturated monomers which are copolymerizable with component (a). The proportions of the respective components (a), (b), and (c) are preferably selected so that the polymerization product has a glass transition temperature of <0 ° C, more preferably between -20 and -50 ° C (DSC). It is particularly advantageous, the monomers of component (a) in a proportion of 45 to 99 wt .-%, the monomers of component (b) in a proportion of 1 to 15 wt .-% and the monomers of component (c) in a proportion of 0 to 40 wt .-% to choose (the data are based on the monomer mixture for the "base polymer", ie without additives of any additives to the finished polymer, such as resins, etc.).

The monomers of component (a) are, in particular, plasticizing and / or nonpolar monomers. Preferably used as monomers (a) are acrylic and methacrylic acid esters having alkyl groups consisting of 4 to 14 C atoms, particularly preferably 4 to 9 C atoms. Examples of such monomers are n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, n-pentyl methacrylate, n-amyl acrylate, n-hexyl acrylate, n-hexyl methacrylate, n-heptyl acrylate, n-octyl acrylate, n-octyl methacrylate, n-nonyl acrylate and their branched isomers such as isobutyl acrylate, isooctyl acrylate, isooctyl methacrylate, 2-ethylhexyl acrylate or 2-ethylhexyl methacrylate. The monomers of component (b) are, in particular, olefinically unsaturated monomers having functional groups, in particular having functional groups capable of undergoing reaction with epoxide groups. For component (b), preference is given to using monomers having functional groups which are selected from the group comprising: hydroxyl, carboxy, sulfonic or phosphonic acid groups, acid anhydrides, epoxides, amines.

Particularly preferred examples of monomers of component (b) are acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, aconitic acid, dimethylacrylic acid, β-acryloyloxypropionic acid, trichloroacrylic acid, vinylacetic acid, vinylphosphonic acid, maleic anhydride, hydroxyethyl acrylate, in particular 2-hydroxyethyl acrylate, hydroxypropyl acrylate, in particular 3 Hydroxypropyl acrylate, hydroxybutyl acrylate, in particular 4-hydroxybutyl acrylate, hydroxyhexyl acrylate, in particular 6-hydroxyhexyl acrylate, hydroxyethyl methacrylate, in particular 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, in particular 3-

Hydroxypropyl methacrylate, hydroxybutyl methacrylate, especially 4-

Hydroxybutyl methacrylate, hydroxyhexyl methacrylate, especially 6-hydroxyhexyl methacrylate, allyl alcohol, glycidyl acrylate, glycidyl methacrylate. In principle, all vinylically functionalized compounds which are copolymerizable with component (a) and / or component (b) can be used as component (c). The monomers of component (c) can serve to adjust the properties of the resulting PSA. Exemplary monomers of component (c) are:

Methylacrylate, ethylacrylate, propylacrylate, methylmethacrylate, ethylmethacrylate, benzylacrylate, benzylmethacrylate, sec-butylacrylate, ie f-butylacrylate, phenylacrylate, phenylmethacrylate, isobornylacrylate, isobornylmethacrylate, ie / f-butylphenylacrylate, tert-butylaphenylmethacrylate, dodecylmethacrylate, isodecylacrylate, laurylacrylate, n-undecylacrylate , Stearyl acrylate, tridecyl acrylate, behenyl acrylate, cyclohexyl methacrylate, cyclopentyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2-butoxyethyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 3,5-dimethyl adamantyl acrylate, 4-cumylphenyl methacrylate, cyanoethyl acrylate, cyanoethyl methacrylate, 4 Biphenyl acrylate, 4-biphenyl methacrylate, 2-naphthyl acrylate, 2-naphthyl methacrylate, tetrahydrofurfuryl acrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, Dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, 2-butoxyethyl acrylate, 2-butoxyethyl methacrylate, 3-methoxyacrylic acid methyl ester, 3-methoxybutyl acrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, 2-phenoxyethyl methacrylate,

Butyl diglycol methacrylate, ethylene glycol acrylate, ethylene glycol monomethyl acrylate, methoxy polyethylene glycol methacrylate 350, methoxy polyethylene glycol methacrylate 500, propylene glycol monomethacrylate, butoxy diethylene glycol methacrylate, ethoxy triethylene glycol methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 1,1,3,3-hexafluoroisopropyl acrylate, 1, 1, 1, 3,3,3-hexafluoroisopropyl methacrylate, 2,2,3,3,3-pentafluoropropyl methacrylate, 2,2,3,4,4,4-hexafluorobutyl methacrylate, 2,2,3, 3,4,4,4-heptafluorobutyl acrylate, 2,2,3,3,4,4,4-heptafluorobutyl methacrylate, 2,2,3,3,4,4,5,5,6,6,7, 7,8,8,8-pentadecafluorooctyl methacrylate, dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, Λ / - (1-methyl-undecyl) acrylamide, / V- (n-butoxymethyl) acrylamide, / V- (butoxymethyl) methacrylamide, N- (ethoxymethyl) acrylamide , / V- (n-octadecyl) acrylamide, furthermore Λ /, / V-dialkyl-substituted amides, such as Λ /, / V-dimethylacrylamide, Λ /, / V-dimethylme thacrylamide, N-benzylacrylamide, / V-isopropylacrylamide, / V-ie / f-butylacrylamide, / V-ie f-octylacrylamide, N-methylolacrylamide, / V-methylolmethacrylamide, acrylonitrile, methacrylonitrile, vinyl ethers, such as vinyl methyl ether, ethyl vinyl ether, vinyl isobutyl ether, Vinyl esters, such as vinyl acetate, vinyl chloride, vinyl halides, vinylidene chloride, vinylidene halides, vinylpyridine, 4-vinylpyridine, / V-vinylphthalimide, / V-vinyllactam, / V-vinylpyrrolidone, styrene, α- and p-methylstyrene, α-butylstyrene, 4-n Butylstyrene, 4-n-decylstyrene, 3,4-dimethoxystyrene, macromonomers such as 2-polystyrene ethyl methacrylate (weight average molecular weight Mw, as determined by GPC, from 4000 to 13000 g / mol), poly (methyl methacrylate) ethyl methacrylate (Mw from 2000 to 8000 g / mol).

Monomers of component (c) may advantageously also be chosen such that they contain functional groups which promote a subsequent radiation-chemical crosslinking (for example by electron beams, UV). Suitable copolymerizable photoinitiators are, for example, benzoin acrylate and acrylate-functionalized benzophenone derivatives. Monomers which promote electron beam crosslinking are, for example, tetrahydrofurfuryl acrylate, N-he / f-butylacrylamide and allyl acrylate.

The preparation of the polyacrylates ("polyacrylates" is understood in the context of the invention to be synonymous with "poly (meth) acrylates") can be familiar to the person skilled in the art Processes are carried out, in particular advantageous by conventional free-radical polymerizations or controlled radical polymerizations. The polyacrylates can be prepared by copolymerization of the monomeric components using the usual polymerization initiators and optionally regulators, being polymerized at the usual temperatures in bulk, in emulsion, for example in water or liquid hydrocarbons, or in solution.

Preferably, the polyacrylates are prepared by polymerization of the monomers in solvents, in particular in solvents having a boiling range of 50 to 150 ° C, preferably from 60 to 120 ° C using the usual amounts of polymerization initiators, generally at 0.01 to 5, in particular at 0.1 to 2 wt .-%, based on the total weight of the monomers, are prepared.

In principle, all known to the expert, customary initiators are. Examples of radical sources are peroxides, hydroperoxides and azo compounds, for example dibenzoyl peroxide, cumene hydroperoxide, cyclohexanone peroxide, di-i-butyl peroxide, cyclohexylsulfonylacetyl peroxide, diisopropyl percarbonate, ί-butyl peroctoate, benzpinacol. In a very preferred procedure, the free-radical initiator used is 2,2'-azobis (2-methylbutyronitrile) (Vazo® 67 ™ from DuPont) or 2,2'-azobis (2-methylpropionitrile) (2,2'-azobisisobutyronitrile; AIBN Vazo® 64 ™ from DuPont).

Suitable solvents for the preparation of the poly (meth) acrylates are alcohols such as methanol, ethanol, n- and iso-propanol, n- and iso-butanol, preferably isopropanol and / or isobutanol, and hydrocarbons such as toluene and in particular gasoline having a boiling range of 60 up to 120 ° C in question. It is also possible to use ketones, such as, preferably, acetone, methyl ethyl ketone, methyl isobutyl ketone and esters, such as ethyl acetate, and mixtures of solvents of the type mentioned, with mixtures containing isopropanol, in particular in amounts of from 2 to 15% by weight, preferably from 3 to 10% by weight. , based on the solvent mixture used, are preferred.

Preferably, after the preparation (polymerization) of the polyacrylates, a concentration takes place, and the further processing of the polyacrylates takes place essentially solvent-free. The concentration of the polymer can be done in the absence of crosslinker and accelerator substances. But it is also possible, one add these classes of compounds to the polymer before concentration, so that the concentration then takes place in the presence of this substance (s). The weight-average molecular weights M _{w of} the polyacrylates are preferably in a range from 20,000 to 2,000,000 g / mol; more preferably in a range of 100,000 to 1,500,000 g / mol, most preferably in a range of 150,000 to 1,000,000 g / mol. The data of the average molecular weight M _w and the polydispersity PD in this document relate to the determination by gel permeation chromatography. For this purpose, it may be advantageous to carry out the polymerization in the presence of suitable polymerization regulators such as thiols, halogen compounds and / or alcohols in order to set the desired average molecular weight.

The polyacrylates preferably have a K value of 30 to 90, particularly preferably 40 to 70, measured in toluene (1% solution, 21 ° C). The K value according to Fikentscher is a measure of the molecular weight and the viscosity of the polymer.

Especially suitable according to the invention are polyacrylates which have a narrow molecular weight distribution (polydispersity PD <4). Despite relatively low molecular weight after crosslinking, these compositions have a particularly good shear strength. In addition, the lower polydispersity allows for easier melt processing, since the flow viscosity is lower compared to a more widely dispersed polyacrylate with largely similar application properties. Narrowly distributed poly (meth) acrylates can be advantageously prepared by anionic polymerization or by controlled radical polymerization, the latter being particularly well suited. Also via / V-Oxyle can be produced corresponding polyacrylates. Furthermore, atom transfer radical polymerization (ATRP) can advantageously be used for the synthesis of narrowly distributed polyacrylates, preference being given to initiating monofunctional or difunctional secondary or tertiary halides and to abstraction of the halide (s) Cu, Ni, Fe -, Pd, Pt, Ru, Os, Rh, Co, Ir, Ag or Au complexes are used.

The monomers for preparing the poly (meth) acrylates preferably contain proportionate functional groups which are suitable with epoxy groups linking reactions enter into. This advantageously allows thermal crosslinking of the polyacrylates by reaction with epoxides. By linking reactions are meant in particular addition and substitution reactions. Thus, it is preferable to link the building blocks carrying the functional groups with building blocks bearing epoxy groups, in particular in the sense of crosslinking the polymer building blocks carrying the functional groups via crosslinking molecules carrying epoxide groups as bridging bridges. The epoxide group-containing substances are preferably multifunctional epoxides, ie those having at least two epoxide groups; Accordingly, it is preferable in total to an indirect linkage of the blocks carrying the functional groups.

The poly (meth) acrylates of the PSA of the invention are preferably crosslinked by linking reactions - in particular in the context of addition or substitution reactions - of functional groups contained in them with thermal crosslinkers. It is possible to use all thermal crosslinkers which ensure both a sufficiently long processing time, so that there is no gelling during the processing process, in particular the extrusion process, as well as a rapid post-crosslinking of the polymer to the desired degree of crosslinking at temperatures lower than the processing temperature , especially at room temperature, lead. For example, a combination of polymers containing carboxyl, amine and / or hydroxyl groups and isocyanates, in particular aliphatic or amine-deactivated trimerized isocyanates, as crosslinkers is possible. Suitable isocyanates are in particular trimerized derivatives of MDI [4,4-methylene di (phenyl isocyanate)], HDI [hexamethylene diisocyanate, 1,6-hexylene diisocyanate] and / or IPDI [isophorone diisocyanate, 5-isocyanato-1-isocyanatomethyl-1, 3, 3-trimethylcyclohexane], for example the types Desmodur® N3600 and XP2410 (in each case BAYER AG: aliphatic polyisocyanates, low-viscosity HDI trimers). Also suitable is the surface-deactivated dispersion of micronized trimerized IPDI BUEJ 339®, now HF9® (BAYER AG).

Basically suitable for crosslinking, however, are also other isocyanates such as Desmodur VL 50 (polyisocyanates based on MDI, Bayer AG), Basonat F200WD (aliphatic Polyisocyanate, BASF AG), Basonat HW100 (water-emulsifiable polyfunctional isocyanate based on HDI, BASF AG), Basonat HA 300 (allophanate-modified polyisocyanate based on isocyanurate, HDI-based, BASF) or Bayhydur VPLS2150 / 1 (hydrophilic modified IPDI, Bayer AG ).

Preference is given to using thermal crosslinkers at from 0.1 to 5% by weight, in particular from 0.2 to 1% by weight, based on the total amount of the polymer to be crosslinked.

The poly (meth) acrylates of the PSA of the invention are preferably crosslinked by means of epoxide (s) or by means of one or more epoxide group-containing substance (s). The epoxide group-containing substances are in particular multifunctional epoxides, ie those having at least two epoxide groups; Accordingly, there is an overall indirect linkage of the functional groups bearing blocks of poly (meth) acrylates. The epoxide group-containing substances can be both aromatic and aliphatic compounds.

Highly suitable multifunctional epoxides are oligomers of epichlorohydrin, polyether polyhydric alcohols (especially ethylene, propylene and butylene glycols, polyglycols, thiodiglycols, glycerol, pentaerythritol, sorbitol, polyvinyl alcohol, polyallylalcohol and the like), epoxy ethers of polyhydric phenols [especially resorcinol, hydroquinone, bis - (4-hydroxyphenyl) -methane, bis (4-hydroxy-3-methylphenyl) -methane, bis (4-hydroxy-3,5-dibromophenyl) -methane, bis (4-hydroxy-3,5- difluorophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) -propane, 2 , 2-bis- (4-hydroxy-3-chlorophenyl) -propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) -propane, 2,2-bis- (4-hydroxy-3, 5-dichlorophenyl) propane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -4'-methylphenylmethane, 1, 1 - bis (4-hydroxyphenyl) -2,2,2-trichloroethane, bis (4-hydroxyphenyl) - (4-chlorophenyl) -meth 1, 1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) cyclohexylmethane, 4,4'-dihydroxydiphenyl, 2,2'-dihydroxydiphenyl, 4,4'-dihydroxydiphenylsulfone] and their hydroxyethyl ethers , Phenol-formaldehyde condensation products, such as phenol alcohols, phenol-aldehyde resins and similar, S- and N-containing epoxides (for example, N, N-diglycidylanillin, N, N'-dimethyldiglycidyl-4,4-diaminodiphenylmethane) and epoxides, which by conventional methods have been prepared from polyunsaturated carboxylic acids or monounsaturated carboxylic acid residues of unsaturated alcohols, Glycidyl esters, polyglycidyl esters, which can be obtained by polymerization or copolymerization of glycidyl esters of unsaturated acids or from other acidic compounds (cyanuric acid, diglycidyl sulfide, cyclic trimethylene trisulfone or their derivatives and others) are available.

Very suitable ethers are, for example, 1,4-butanediol diglycidyl ether, polyglycerol-3-glycidyl ether, cyclohexanedimethanol diglycidyl ether, glycerol triglycidyl ether, neopentylglycol diglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

Particularly preferred for the poly (meth) acrylates as polymers to be crosslinked is the use of a crosslinking accelerator system ("crosslinking system") described, for example, in EP 1 978 069 A1, for better control over both processing time, crosslinking kinetics and degree of crosslinking The crosslinker-accelerator system comprises at least one substance containing epoxide groups as crosslinker and at least one substance accelerating at a temperature below the melting temperature of the polymer to be crosslinked for crosslinking reactions by means of compounds containing epoxide groups as accelerator.

According to the invention, particular preference is given to amines (formally as substitution products of ammonia, in the following formulas these substituents are represented by "R" and include in particular alkyl and / or aryl radicals and / or other organic radicals), particularly preferably such amines, which undergo no or only minor reactions with the building blocks of the polymers to be crosslinked.

In principle, it is possible to select both primary (NRH ₂ ), secondary (NR ₂ H) and tertiary amines (NR ₃ ) as accelerators, of course also those which have a plurality of primary and / or secondary and / or tertiary amine groups. However, particularly preferred accelerators are tertiary amines such as triethylamine, triethylenediamine, benzyldimethylamine, dimethylamino-methylphenol, 2,4,6-tris- (N, N-dimethylaminomethyl) -phenol, N, N'-bis (3- (dimethyl-amino ) propyl) urea. As accelerators may also be advantageous multifunctional amines such as diamines, triamines and / or tetramines are used. For example, diethylenetriamine, triethylenetetramine, trimethylhexamethylenediamine are excellent.

In addition, amino alcohols are preferably used as accelerators. Secondary and / or tertiary amino alcohols are particularly preferably used, wherein in the case of several amine functionalities per molecule, preferably at least one, preferably all amine functionalities are secondary and / or tertiary. Preferred amino alcohol accelerators may be triethanolamine, N, N-bis (2-hydroxypropyl) ethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, 2-aminocyclohexanol, bis (2-hydroxycyclohexyl) methylamine, 2- (diisopropylamino) ethanol, 2- Dibutylamino) ethanol, N-butyldiethanolamine, N-butylethanolamine, 2- [bis (2-hydroxyethyl) amino] -2- (hydroxymethyl) -1, 3-propanediol, 1 - [bis (2-hydroxyethyl) amino] -2- propanol, triisopropanolamine, 2- (dimethylamino) ethanol, 2- (diethylamino) ethanol, 2- (2-dimethylaminoethoxy) ethanol, N, N, N'-trimethyl-N'-hydroxyethyl bisaminoethyl ether, Ν, Ν, Ν'-trimethylaminoethylethanolamine and / or Ν, Ν, Ν'-

Trimethylaminopropylethanolamin be used.

Other suitable accelerators are pyridine, imidazoles (such as 2-methylimidazole) and 1,8-diazabicyclo [5.4.0] undec-7-ene. Cycloaliphatic polyamines can also be used as accelerators. Also suitable are phosphate-based accelerators, such as phosphines and / or phosphonium compounds, for example triphenylphosphine or tetraphenylphosphonium tetraphenylborate.

Acrylic PSAs are typically radically polymerized copolymers of alkyl acrylates or alkyl methacrylates of C1 to C20 alcohols such as methyl acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2 Ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, iso-octyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate,

Tetradecyl (meth) acrylate, lauryl (meth) acrylate, oleyl (meth) acrylate, palmityl (meth) acrylate and stearyl (meth) acrylate in addition to other (meth) acrylic acid esters such as isobornyl (meth) acrylate, benzyl (meth) acrylate, phenyl ( meth) acrylate and 2 bromoethyl (meth) acrylate, alkoxyalkyl (meth) acrylates such as ethoxyethyl (meth) acrylate. Also included are esters of ethylenically unsaturated di- and tricarboxylic acids and anhydrides such as ethyl maleate, dimethyl fumarate and ethyl methyl itaconate. Also vinylaromatic monomers such as styrene, vinyltoluene, methylstyrene, n-butylstyrene, decylstyrene, among others.

 Further possible monomers are vinyl esters of carboxylic acids containing up to 20 carbon atoms, such as vinyl acetate or vinyl laurate, vinyl ethers of alcohols containing up to 10 carbon atoms such as vinyl methyl ether or vinyl isobutyl ether, vinyl halides such as vinyl chloride or vinylidene dichloride, nitriles such as acrylonitrile or methacrylonitrile, acid amides such as acrylamide or methacrylamide and unsaturated hydrocarbons with 2 to 8 carbon atoms such as ethylene, propene, butadiene, isoprene, 1-hexene or 1-octene.

To influence the physical and optical properties of the PSA, polyfunctional ethylenically unsaturated monomers are suitable as crosslinking monomers. Examples include divinylbenzene, alkyl diacrylates such as 1, 2-ethylene glycol diacrylate, 1, 4-butanediol diacrylate, 1, 6 hexanediol diacrylate, 1, 8-octanediol diacrylate or 1, 12-dodecanediol diacrylate, triacrylates such as trimethylolpropane triacrylate and tetraacrylates such as pentaerythritol tetraacrylate. The group of polyfunctional monomers also includes UV-crosslinkable monomers, such as (meth) acrylate-functionalized derivatives of benzophenone or benzoin.

 Another group of monomers are those which create a latent crosslinking potential in the polymer and after the drying of the adhesive spontaneously (often catalysed) lead to a network structure. Such a monomer is, for example, glycidyl methacrylate whose oxirane ring with hydroxyl or in particular carboxylate functions leads to a covalent bond under ring opening. This reaction occurs more rapidly in the presence of zinc ions or, especially in the presence of carboxyl functions, amines.

To achieve tacky properties, the processing temperature of the adhesive must be above its glass transition temperature to have viscoelastic properties.

Furthermore, it is possible to use acrylate-based activatable adhesives according to the invention. Thus, the activatable adhesives in a particularly preferred embodiment then consist of a base polymer a) consisting of

a1) 40 to 95 wt .-% of acrylic acid ester and / or methacrylic acid ester having the following formula

CH ₂ = C (R i) (COOR ₂ ), where Ri = H or CH ₃ and R ₂ = H and / or alkyl chains having 1 to 30 carbon atoms.

a2) from 5 to 30% by weight of a copolymerizable vinyl monomer having at least one carboxylic acid and / or sulfonic acid and / or phosphonic acid group a3) from 1 to 10% by weight of a copolymerizable vinyl monomer having at least one epoxy group or one acid anhydride function

a4) 0 to 20 wt .-% of a copolymerizable vinyl monomer, which can contribute to the functional group for increasing the cohesion, increasing the reactivity of the crosslinking, or for direct crosslinking, and

b) 5 to 50 wt .-% of an epoxy resin or a mixture of several epoxy resins

The polymer a) may comprise an activatable pressure-sensitive adhesive which becomes tacky under the action of temperature and optional pressure and builds up a high bond strength after bonding and cooling as a result of the solidification. Depending on the application temperature, these activatable PSAs have different static glass transition temperatures T _G, A or a melting point T _S, A.

In a very preferred embodiment, acrylic monomers are used for the monomers a1) which comprise acrylic and methacrylic acid esters having alkyl groups consisting of 4 to 14 C atoms, preferably 4 to 9 C atoms. Specific examples, without wishing to be limited by this list, are n-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-nonyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, and their branched isomers such as, for example 2-ethylhexyl acrylate. Further classes of compounds which can also be added in small amounts under c1) are methyl methacrylates, cyclohexyl methacrylates, isobornyl acrylate and isobornyl methacrylates.

In a preferred manner, the monomers a2) used are itaconic acid, acrylic acid, methacrylic acid, vinylacetic acid, fumaric acid, crotonic acid, aconitic acid, dimethylacrylic acid, β-acryloyloxypropionic acid, trichloroacrylic acid, vinylphosphonic acid, vinylsulfonic acid and vinylsulfonic acid.

In a preferred manner, the monomers a3) used are glycidyl methacrylate, maleic anhydride and itaconic anhydride. In a very preferred embodiment, monomers a4) use vinyl esters, vinyl ethers, vinyl halides, vinylidene halides, vinyl compounds having aromatic rings and heterocycles in the α-position. Here again, not only a few examples are mentioned: vinyl acetate, vinyl formamide, vinyl pyridine, ethyl vinyl ether, vinyl chloride, vinylidene chloride and acrylonitrile.

 In a further very preferred design for the monomers a4), monomers having the following functional groups are used: hydroxyl, acid amide, isocyanato or amino groups.

Further particularly preferred examples of component a4) are hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate,

Hydroxypropylmethacrylate, allylalcohol, acrylamide, benzylacrylate, benzylmethacrylate, phenylacrylate, phenylmethacrylate, t-butylphenylacrylate, t-butylaphenylmethacrylate, phenoxyethylacrlylate, phenoxyethylmethacrylate, 2-butoxyethylmethacrylate, 2-butoxyethylacrylate, dimethylaminoethylmethacrylate, dimethylaminoethylacrylate, diethylaminoethylmethacrylate, diethylaminoethylacrylate, cyanoethylmethacrylate, cyanoethylacrylate, 6-hydroxyhexylmethacrylate, N-tert-butylacrylamide, N-methylolmethacrylamide, N- (buthoxymethyl) methacrylamide, N-methylolacrylamide, N- (ethoxymethyl) acrylamide, N-isopropylacrylamide, tetrahydrofurfuryl acrylate, but this list is not exhaustive.

In a further preferred version aromatic vinyl compounds are used for the component a4), wherein preferably the aromatic rings selected from C ₄ to C ₈ exist and may also contain heteroatoms. Particularly preferred examples are styrene, 4-vinylpyridine, N-vinylphthalimide, methylstyrene, 3,4-dimethoxystyrene, 4-vinylbenzoic acid, although this list is not exhaustive.

For the polymerization, the monomers are in turn chosen so that the resulting polymers can be used as industrially useful adhesives or PSAs, in particular such that the resulting polymers adhesive or pressure-sensitive adhesive properties according to the "Handbook of Pressure Sensitive Sensitive Adhesive Technology" by Donatas Satas (van Nostrand Again, control of the desired glass transition temperature can be achieved by the application of Fox's equation (G1) in the composition of the monomer mixture that underlies the polymerization PSAs, the static glass transition temperature of the resulting polymer is advantageously below 15 ° C.

To obtain a glass transition temperature T _G, A of the polymers of T _G, A ^ 30 ° C for heat-activable adhesive according to the above, the monomers are very preferably selected and the quantitative composition of the monomer mixture advantageously selected such that according to the Fox Equation (G1) (see TG Fox, Bull. Am. Phys Soc., 1 (1956) 123) gives the desired T _{G, A} value for the polymer. w _r

 (G1)

 T, G, n

Here n represents the number of runs via the monomers used, w _n the mass fraction of the respective monomer n (wt .-%) and T _{G, n} the respective glass transition temperature of the homopolymer of the respective monomers n in K.

To prepare the adhesives, conventional free-radical polymerizations or controlled free-radical polymerizations are advantageously carried out. Initiator systems which additionally comprise further free-radical initiators for the polymerization, in particular thermally decomposing radical-forming azo or peroxo initiators, are preferably used for the free-radical polymerizations. In principle, however, all acrylates customary to the person skilled in the art are suitable. The production of C-centered radicals is described in Houben Weyl, Methods of Organic Chemistry, Vol. E 19a, pages 60 to 147. These methods are preferably applied by analogy.

Examples of radical sources are peroxides, hydroperoxides and azo compounds, as some non-exclusive examples of typical free-radical initiators are potassium peroxodisulfate, dibenzoyl peroxide, cumene hydroperoxide, cyclohexanone peroxide, di-t-butyl peroxide, Azodiisosäurebutyronitril, Cyclohexylsulfonylacetylperoxid, diisopropyl percarbonate, t-butyl peroctoate, Benzpinacol. In a very preferred embodiment, the free-radical initiator used is 1, 1'-azobis (cyclohexanecarbonitrile) (Vazo 88 ™ from DuPont). The average molecular weights M _n of the PSAs formed in the free-radical polymerization are very preferably selected such that they are in a range from 20,000 to 2,000,000 g / mol; PSAs having average molecular weights M _n of 100,000 to 500,000 g / mol are produced especially for further use as hotmelt PSAs.

The polymerization may be carried out neat, in the presence of one or more organic solvents, in the presence of water or in mixtures of organic solvents and water. The aim is to keep the amount of solvent used as low as possible.

The polymerization time is - depending on the conversion and temperature - between 4 and 72 hours. The higher the reaction temperature can be selected, that is, the higher the thermal stability of the reaction mixture, the lower the reaction time can be selected.

To increase the cohesion between the adhesive and the film, the film may be subjected to a corona treatment.

Furthermore, an etching of the film is advantageous in order to be able to anchor the adhesive.

 In a variant of the invention, a primer is present between lower film and adhesive to improve the adhesion of the adhesive to the film.

Descriptions of the commonly used primers can be found, for example, in the "Handbook of Pressure Sensitive Adhesive Technology" by Donatas Satas (van Nostrand, 1989).

Preferably, the upper and lower foils in the blank have the same shape and size and are congruently arranged.

More preferably, these conditions also apply to any other existing films.

A typical size for the diecut, with which many of the smaller holes can be closed, represents a (circular) disc with a diameter of 10 to 60 mm, in particular 30 to 40 mm. Preferably, the lower film is coated over its entire surface with the adhesive.

The inventive method for closing a hole, in particular in a body with a punched product according to the invention is characterized by the following steps:

 • Applying the stamping on the hole to be closed so that the hole is completely covered by the stamping

 • Influence of temperatures of 120 ° C to 200 ° C, in particular 175 ° C for 15 min on the diecut, so that the heat-activatable adhesive hardens and thereby the hole is closed

The punched product also withstands temperatures of, for example, 190 ° C. or more for a few minutes, for example if there is a plant breakdown and the (automobile) bodies are left in the drying ovens for longer.

The curing of the adhesive preferably takes place by supplying heat during the customary finishing process of the body shell, in particular during the painting, underbody protection or CDP drying. In this way, no additional operation is required.

 Due to the required heating of the body during said drying processes, there is enough energy.

 Alternatively, by a local energy supply by heat or infrared radiators possible. It is preferred if the stamped body is applied concentrically over the hole to be closed.

 Advantageously, the contours of the blank correspond to the contour of the hole to be closed. This results in a symmetrical projection of the individual layers of the stamped product. The supernatant is preferably between 1 and 20 mm, more preferably between 5 and 10 mm.

The stamped product according to the invention is superior to the known from the prior art solutions, especially at elevated mechanical stress. The same is true when considering the noise attenuation. The noise damping and the Strength are massively improved by the use of a carrier laminate with a heavy foil.

 Furthermore, a single embodiment of the stamped product can cover a plurality of holes of different sizes.

The stamping is characterized by:

 • a very high load capacity / dielectric strength

 • very good seal against moisture / moisture barrier

 • good seal against noise / noise reduction

The puncture resistance is determined by closing a hole with a punched product and piercing it in a targeted manner. In this case, a mandrel is clamped in a tensile testing machine, which moves at a constant speed to the horizontally positioned, closed hole and pierces it by 30 mm. The force to be expended is measured.

According to an advantageous embodiment of the invention, the diecut has puncture strengths of 200 to 2000 N. The surface of the stamped part offers an appealing and smooth surface in the points optics and haptics

Test Methods

The measurements are (unless otherwise stated) at a test climate of 23 ± 1 ° C and 50 ± 5% rel. Humidity carried out.

Molecular weight Mn and the weight-average molecular weight Mw

The statements of the number-average molar mass Mn and the weight-average molar mass Mw in this document refer to the determination by gel permeation chromatography (GPC). The determination is carried out on 100 μΙ clear filtered sample (sample concentration 4 g / l). The eluent used is tetrahydrofuran with 0.1% by volume of trifluoroacetic acid. The measurement takes place at 25 ° C.

As a precolumn is a column type PSS SDV, 5 μηι, 10 ³ Ä, 8.0 mm * 50 mm (information here and below in the order: type, particle size, porosity, inner diameter * length, 1 Ä = 10 ^"10 For separation, a combination of the columns of the type PSS-SDV, 5 [Jim, 10 ³ Ä and 10 ⁵ Ä and 10 ⁶ Ä, each with 8.0 mm * 300 mm used (columns from Polymer Standards Service; Detection by means of a differential refractometer Shodex RI71) The flow rate is 1, 0 ml per minute The calibration is carried out with polyacrylates against PMMA standards (polymethyl methacrylate calibration) and otherwise (resins, elastomers) against PS standards (polystyrene calibration).

The polyacrylates preferably have a K value of 30 to 90, particularly preferably 40 to 70, measured in toluene (1% solution, 21 ° C). The K value according to Fikentscher is a measure of the molecular weight and the viscosity of the polymer.

K value

The principle of the method is based on the capillary-viscometric determination of the relative solution viscosity. For this purpose, the test substance is dissolved in toluene by shaking for 30 minutes, so that a 1% solution is obtained. In a Vogel-Ossag viscometer, the flow time is measured at 25 ° C and determined therefrom in relation to the viscosity of the pure solvent, the relative viscosity of the sample solution. According to Fikentscher [P. E. Hinkamp, Polymer, 1967, 8, 381] read off the K value (K = 1000 k).

Glass transition temperature

The glass transition temperature is determined by dynamic scanning calorimetry (DSC). For this purpose, 5 mg of an untreated polymer sample are weighed into an aluminum crucible (volume 25 μί) and closed with a perforated lid. For measurement, a DSC 204 F1 from Netzsch is used. It will for inerting under nitrogen. The sample is first cooled to -150 ° C, then heated at a heating rate of 10 K / min to +150 ° C and again cooled to - 150 ° C. The subsequent second heating curve is driven again at 10 K / min and recorded the change in heat capacity. Glass transitions are recognized as steps in the thermogram.

The glass transition temperature is evaluated as follows (see FIG. 2):

A tangent is applied to the baseline of the thermogram before © and after © of the step. In the area of the step, a straight line © parallel to the ordinate is placed so that it intersects the two tangents in such a way that two faces © and © (between the one tangent, the equalization line and the trace) of the same content are created. The intersection of the thus positioned regression line with the trace gives the glass transition temperature

In the following, the punched article is intended to be explained in more detail with reference to a figure for the permanent closing of holes, in particular in metal sheets or in plastic parts of automobile bodies, without being intended to be limiting in any way. It shows

1 shows a hole in a body, which is to be closed, and the state after the hole to be closed is closed by the action of heat.

In the body 5, a hole 6 is structurally present, it applies to be closed.

For this purpose, a stamped article 1 with a carrier made of a laminate of at least two plastic films, namely an upper film 2 and a lower film 3, wherein the lower film 3 has a basis weight of at least 1, 5 kg / m ² , and a curable adhesive 4th fixed on the hole 6 so that the hole 6 is completely covered by the blank. The surface of the stamped product 1 is larger than the area of the hole 6 to be closed.

The stamped product 1 is permanently connected to the body 5 by briefly acting on the stamped high temperatures that lead to the activation of the adhesive 4.

Claims

Patent claims

Die-cut, especially for permanently closing holes, especially in sheet metal or plastic parts,

with a carrier made of a laminate of at least two plastic films, the lower film having a basis weight of at least 1.5 kg/m ² and an adhesive, in particular a curable or self-adhesive adhesive, being applied to the side of the lower film opposite the upper film.

Diecut according to claim 1,

characterized in that

the lower film has a basis weight between 1.5 and 6 kg/m ² , preferably between 1.5 and 3.9 kg/m ² and between 1.5 and 2.5 kg/m ² .

Diecut according to one of claims 1 or 2,

characterized in that

the lower film is a polyolefin film filled with minerals or an elastomer-modified bitumen film.

Diecut according to at least one of claims 1 to 3,

characterized in that

the upper film consists of polyester, more preferably polyethylene terephthalate (PET).

Diecut according to at least one of the previous claims,

characterized in that

the thickness of the upper film is between 15 and 350 μm, preferably between 30 and 200 μm, more preferably between 50 and 150 μm.

Diecut according to at least one of the previous claims,

characterized in that

the thickness of the lower film is between 600 and 3500 μm, preferably between 1,100 and 3500 μm, more preferably between 1700 and 3500 μm.

7. Diecut according to at least one of the previous claims,

characterized in that

An acrylate-based self-adhesive is chosen as the adhesive.

8. Diecut according to at least one of the previous claims,

characterized in that

A reactive heat-activatable adhesive is selected as the adhesive.

9. diecut according to at least one of the previous claims,

characterized in that

a reactive heat-activated adhesive made of nitrile rubber and phenolic resin is used.

10. Diecut according to at least one of the previous claims,

characterized in that

the diecut is applied concentrically over the hole to be closed.

1 1 . Diecut according to at least one of the previous claims,

characterized in that

the contours of the die-cut correspond to the contour of the hole to be closed.

12. A method for closing a hole, in particular in a body, with a diecut according to at least one of the preceding claims, characterized by the following steps:

Applying the diecut to the hole to be closed in such a way that the hole is in particular completely covered by the diecut,

Exposure of the die-cut to temperatures of 120 °C to 200 °C for 15 minutes so that the heat-activated adhesive hardens and the hole is thereby closed

13. Method according to claim 9,

characterized in that

the contours of the die-cut correspond to the contour of the hole to be closed, in particular that the projection is between 1 and 20 mm, more preferably between 5 and 10 mm.

14. Hole in particular in a body with a diecut according to at least one of the previous claims.