EP1343630A1

EP1343630A1 - Multi-layered composite material with organic sandwich layers based on rubber

Info

Publication number: EP1343630A1
Application number: EP01991803A
Authority: EP
Inventors: Ralf Sauer; Peter Born; Angelika Butt
Original assignee: Henkel Teroson GmbH
Current assignee: Henkel AG and Co KGaA
Priority date: 2000-12-16
Filing date: 2001-12-07
Publication date: 2003-09-17
Also published as: WO2002047901A1; AU2002231673A1; DE10062859A1; US20040076841A1

Abstract

Adhesive compositions based on vulcanisable rubber materials, containing liquid polyenes, optionally solid rubbers and/or thermoplastic polymer powders and vulcanising agents are suitable for the production of multi-layered laminates, comprising two external metal sheets and an adhesive sandwich layer. Said sandwich layer can optionally comprise additional flat materials made from synthetic fibres and/or metallic expanded mesh, wire mesh or similar. Said multi-layered laminates are suitable for the inclusion of intrinsically light materials in machine, vehicle or instrument construction, in particular in automobile construction.

Description

multilayer composite materials with organic intermediate layers based on rubber

The present invention relates to a multilayer laminate composed of two outer metal sheets and an intermediate layer containing an organic binder matrix, and to a method for producing these multilayer laminates.

Multi-layer laminates and processes for the production of multi-layer laminates are widely used wherever it is important to use specifically light structures with a high level of strength and / or rigidity.

Specifically lightweight materials are increasingly being used in machine, vehicle or device construction, especially in automobile construction, in order to reduce the weight of the vehicles, for example. For example, aluminum, fiber composite materials or high-strength body steels are used. The use of increasingly high strength materials with increasingly thin sheet thicknesses can meet the strength requirements in very many cases, but not the requirements for the rigidity of the components. Lightweight construction with increasingly thin sheet thicknesses reaches its limits especially where, due to the geometry, reduced cross-sections of the components whose rigidity no longer meets the requirements for usability. Examples of known multilayer composites are web plates, hump and trapezoidal composite plates in their various forms. Geometries produced by reshaping with an inner, supporting intermediate layer form the basis for the technical solutions of this type of lightweight construction. Intermediate layers are suitable, inter alia, foam core fillings with polymeric foams or also with metallic foams or inorganic foams based on silicate. Preferred technical applications today are primarily a three-layer material composite consisting of two cover sheets and an intermediate layer made of a viscoelastic material. Due to the relatively thin intermediate layer, which generally hardly contributes to increasing the rigidity, this type of composite sheet is mainly used because of its vibration-damping properties.

DE-A-3905871 discloses a composite material for thermal insulation and / or sound absorption that has a structurally stable covering layer made of a thermally stable metal foil on at least one side. A thermally resistant, highly porous, inorganic material is proposed as the insulation layer, for example foamed glass with a sponge-like structure or gas concrete or foamed ceramic or clay mineral materials. Exhaust areas of an automobile are proposed as an application for this composite material in the automotive sector.

From DE-A-3935120 a method for the production of multilayer composite panels is known, in which this composite panel consists of a cover and base plate and in between a web material made of wire or a metal grid as web material, which prior to its connection to the outer Metal plates is deformed by flattening its lattice nodes. This creates enlarged connection areas between the metal grid and the metal panels, which should also enable reshaping. Although the document states that the connection of the metal grid to the cover plates can in principle be done by adhesive processes, it should preferably be done by welding processes. This document does not provide any further information on suitable adhesives.

WO 00/13890 describes glued multilayer composite panels and methods for producing multilayer composite panels which consist of two outer metal plates which serve as upper and lower base plates and which are bonded to a deformable connecting intermediate layer. The deformable web material lying in the intermediate layer is covered with the Lid and base plate connected by means of a foaming adhesive that fills the voids remaining in the composite. The web material lying between the metal plates can consist of an expanded metal mesh, a wire mesh or a web plate, and it can include a multi-layer sequence of expanded metal meshes, wire meshes, web plates with intermediate plates that are impermeable or permeable to the adhesive. There is no teaching of suitable compositions of the adhesive in this document.

In view of this prior art, the inventors have set themselves the task of providing binders which are suitable for the production of multilayer laminates, in particular for laminates which are composed of outer metal sheets and an intermediate layer.

The solution to the problem according to the invention can be found in the claims, it consists essentially in the provision of multilayer laminates which can be produced from two outer metal sheets and an intermediate layer from a binder matrix and, if appropriate, a sheet-like structure incorporated therein, the binder composition being a vulcanizable one Rubber material based on at least one liquid elastomer with reactive groups.

In a particularly preferred embodiment, the binder is composed such that it enables the production of weight-optimized, lightweight laminates with an acoustic and / or stiffening effect. For this purpose, the binder system can contain, for example, "chemical" blowing agents, or expandable hollow microspheres or expanded hollow microspheres.

Another subject is a process for the production of the aforementioned multilayer laminate, which comprises the following essential process steps: a) application of the vulcanisable to be used according to the invention

Rubber composition using a slot die or a

Roller application device on a metal sheet, b) if applicable, applying the fabric to the rubber composition, c) joining the second sheet of metal, d) if necessary pressing the composite to the predetermined distance, e) curing the rubber adhesive layer by heating the composite to temperatures between 80 ° C. 250 ° C, preferably between 160 ° C and 200 ° C.

The last-mentioned step e) can optionally also be carried out in several stages. For this purpose, the binder composition can be precured in a first curing stage. The multilayer laminate can then be subjected to known forming processes and punching processes, so that, for example, preformed body components can be produced from the laminate, which are joined in a later work step using conventional joining methods such as gluing and / or welding, riveting, screwing, flanging. The final hardening of the binder layer then takes place in a later process step e.g. in the paint oven after electro-painting the body shell of a vehicle.

In another embodiment of the method according to the invention, the vulcanizable rubber composition is not applied directly to a metal sheet, but in a type of "transfer method" to an intermediate carrier. This intermediate carrier can be an anti-adhesive cover film, but it can also be the (reinforcing) flat structure of the intermediate layer for the multilayer laminate. In the last-mentioned embodiment, the binder layer for the intermediate storage can be provided with a cover film which, if necessary, is removed before the binder-coated fabric is applied to the metal sheets.

The binder matrix used according to the invention essentially consists of heat-curing, reactive compositions based on natural and / or synthetic rubbers (ie elastomers containing olefinic double bonds) and vulcanizing agents which contain at least one of the following substances: one or more liquid rubbers and / or solid rubbers or elastomers,

- fine-particle powders made of thermoplastic polymers,

- vulcanizing agents, vulcanization accelerators, catalysts,

- fillers,

- tackifiers and / or adhesion promoters,

- blowing agent,

- extender oils,

- anti-aging agents,

- Rheology aids.

Suitable one-component binders are e.g. described in WO 96/23040, suitable two-component binders are e.g. in EP-A-356715. The teaching of these documents with regard to the rubber compositions is expressly part of the present application.

The liquid rubbers or elastomers can be selected from the following group of homo- and / or copolymers:

Polybutadienes, in particular the 1, 4- and 1, 2-polybutadienes, polybutenes, polyisobutylenes, 1, 4- and 3,4-polyisoprenes, styrene-butadiene copolymers, butadiene-acrylonitrile copolymers, these polymers being terminal and / or (statistically distributed ) may have lateral functional groups. Examples of such functional groups are hydroxyl, amino, carboxyl, carboxylic anhydride or epoxy groups. The molecular weight of these liquid rubbers is typically below 20,000, preferably between 900 and 10,000. The proportion of liquid rubber in the overall composition depends on the desired rheology of the uncured composition and the desired mechanical properties of the cured composition. The proportion of liquid rubber or elastomer normally varies between 5 and 50% by weight of the total formulation. It has proven to be advantageous, preferably mixtures of liquid rubbers of different molecular weights and different configuration in relation to the remaining double bonds. To achieve optimum adhesion to the various substrates, a proportion is used in the particularly preferred formulations

Liquid rubber component with hydroxyl groups or acid anhydride groups used. At least one of the liquid rubbers should contain a high proportion of cis-1,4 double bonds, another a high proportion of vinyl double bonds.

Suitable solid rubbers have a significantly higher molecular weight (MW = 100,000 or higher) compared to the liquid rubbers, examples of suitable rubbers are polybutadiene, preferably with a very high proportion of cis-1,4 double bonds (typically over 95%), styrene-butadiene rubber, Butadiene acrylonitrile rubber, synthetic or natural isoprene rubber, butyl rubber or polyurethane rubber.

The addition of finely divided thermoplastic polymer powders brings a significant improvement in tensile shear strength while maintaining a very high elongation at break, which was previously unusual for structural adhesives. This enables tensile shear strengths of over 15 MPa to be achieved, with the elongation at break being clearly over 15%, very often over 20%. The high-strength structural adhesives based on epoxy resins, even as flexible adhesive formulations, only have elongations at break of less than 5%. A large number of thermoplastic polymer powders are suitable as polymer powders, for example vinyl acetate, either as a homopolymer or as a copolymer with ethylene, such as other olefins and acrylic acid derivatives, polyvinyl chloride, vinyl chloride Λ / inyl acetate copolymers, styrene copolymers, as described, for example, in DE-A -4034725 are described, polymethyl methacrylate and its copolymers with other (meth) acrylic acid esters and functional comonomers, as described for example in DE-C-2454235, or polyvinyl acetals such as polyvinyl butyral. Although the particle size or particle size distribution of the polymer powders does not appear to be particularly critical, the average particle size should be less than 1 mm, preferably less than 350 μm, very particularly preferably between 100 and 20 μm. Most notably polyvinyl acetate or copolymers based on ethylene vinyl acetate are preferred

(EVA). The amount of thermoplastic polymer powder added depends on the desired strength range, it is between 2 and 20% by weight, based on the total composition, a particularly preferred range is 10 to 15%.

Since the crosslinking or curing reaction of the rubber composition has a decisive influence on the tensile shear strength and on the elongation at break of the cured adhesive composition, the vulcanization system must be selected and coordinated with particular care. A large number of vulcanization systems based on elemental sulfur as well as vulcanization systems without elemental sulfur are suitable, the latter being the vulcanization systems based on thiuram disulfides. Vulcanization systems without sulfur compounds can also be used. The latter include vulcanization systems based on organic peroxides, polyfunctional amines, quinones, p-benzoquinone dioxime, p-nitrosobenzene and dinitrosobenzene, or crosslinking with (blocked) diisocyanates. Vulcanization systems based on elemental sulfur and organic vulcanization accelerators and zinc compounds are particularly preferred. The powdered sulfur is used in amounts of 1 to 15% by weight, based on the total composition, and amounts of between 4 and 8% are particularly preferably used. Suitable organic accelerators are the dithiocarbamates (in the form of their ammonium or metal salts), xanthates, thiuram compounds (monosulfides and disulfides), thiazole compounds, aldehyde / amine accelerators (e.g. hexamethylene tetramine) and

Guanidine accelerator, dibenzothiazyl disulfide (MBTS) is very particularly preferred. These organic accelerators are used in amounts of between 2 and 8% by weight, based on the overall formulation, preferably between 3 and 6%. In the zinc compounds acting as accelerators, a choice can be made between the zinc salts of fatty acids, zinc dithiocarbamates, basic zinc carbonates and, in particular, finely divided zinc oxide. The content of zinc compounds is in the range between 1 and 10% by weight, preferably between 3 and 7% by weight. In addition, other typical rubber Vulcanization aids such as fatty acids (eg stearic acid) may be present in the formulation.

Although the compositions to be used according to the invention generally already have very good adhesion to the substrates to be bonded due to the content of liquid rubber with functional groups, if necessary, tackifiers and / or adhesion promoters can be added. For this purpose, for example, hydrocarbon resins, phenolic resins, terpene-phenolic resins, resorcinol resins or their derivatives, modified or unmodified resin acids or esters (abietic acid derivatives), polyamines, polyamino amides, anhydrides and anhydride-containing copolymers are suitable. The addition of polyepoxide resins in small amounts (<1% by weight) can also improve the adhesion on some substrates. For this purpose, however, the solid epoxy resins with a molecular weight of significantly more than 700 are preferably used in finely ground form, so that the formulations are nevertheless essentially free of epoxy resins, in particular those with a molecular weight of less than 700. If tackifiers or adhesion promoters are used, their nature depends and the amount of the polymer composition of the adhesive / sealant, the desired strength of the cured composition and the substrate to which the composition is applied. Typical tackifying resins (tackifiers) such as the terpene phenolic resins or resin acid derivatives are normally used in concentrations between 5 and 20% by weight, typical adhesion promoters such as polyamines, polyaminoamides or resorcinol derivatives are used in the range between 0.1 and 10% by weight.

In principle, all common blowing agents can be used to achieve foaming during the curing process, examples being organic blowing agents from the class of azo compounds, N-nitroso compounds, sulfonylhydrazides or sulfonylsemicarbazides. Examples of the azo compounds to be used according to the invention include azobisisobutyronitrile and in particular azodicarbonamide, from the class of nitroso compounds the di-nitroso-pentamethylenetetramine is mentioned, from the class of sulfohydrazides 4,4'- Oxybis (benzenesulfonic acid hydrazide), the diphenylsulfone-3,3'-disulfohydrazide or the benzene-1,3-disulfohydrazide and from the class of the semicarbazides the p-

Called toluenesulfonyl semicarbazide. In place of the aforementioned blowing agents, the so-called expandable microspheres, i.e. Unexpanded thermoplastic polymer powders occur that are soaked or filled with low-boiling organic liquids.

Such "microspheres" are described, for example, in EP-A-559254, EP-A-

586541 or EP-A-594598. Although not preferred, hollow microspheres which have already been expanded can also be used or also used.

If necessary, these expandable / expanded hollow microspheres can be combined in any quantity ratio with the above-mentioned "chemical" blowing agents. The chemical blowing agents are in foamable

Compositions in amounts between 0.1 and 3% by weight, preferably between 0.2 and 2% by weight, using hollow microspheres between 0.1 and 4% by weight, preferably between 0.2 and 2% by weight.

The compositions to be used according to the invention are preferably free from plasticizers for the thermoplastic polymer. In particular, they are free from phthalic acid esters. However, the rheology of the uncured composition and / or the mechanical properties of the cured composition may need to be adjusted by the addition of so-called extender oils, i.e. aliphatic, aromatic or naphthenic oils. However, this influencing preferably takes place through the appropriate selection of the low molecular weight liquid rubbers or through the use of low molecular weight polybutenes or polyisobutylenes. If extender oils are used, amounts in the range between 2 and 15% by weight are used.

The fillers can be selected from a large number of materials, in particular chalks, naturally ground or precipitated calcium carbonates, calcium magnesium carbonates, silicates, heavy spar, graphite and carbon black. Flake-like fillers, such as, for example, vermiculite, mica, talc or similar sheet silicates, are also suitable as fillers. It may It should be expedient that at least some of the fillers have been surface-pretreated. In particular, a coating with stearic acid has proven to be expedient for the various calcium carbonates or chalks in order to reduce the moisture introduced and to reduce the sensitivity to moisture of the cured composition. In addition, the compositions according to the invention generally contain between 1 and 20% by weight, preferably between 5 and 15% by weight, calcium oxide. The total proportion of fillers in the formulation can vary between 10 and 70% by weight, the preferred range is between 25 and 60% by weight.

Against the thermal, thermooxidative or ozone depletion of the compositions according to the invention, conventional stabilizers such as sterically hindered phenols or amine derivatives are used, typical quantity ranges for these stabilizers are 0.1 to 5% by weight.

Although the rheology of the compositions according to the invention can normally be brought into the desired range by the selection of the fillers and the quantitative ratio of the low-molecular liquid rubbers, conventional rheological aids such as e.g. pyrogenic silicas, bentones or fibrillated or pulp short fibers in the range between 0.1 and 7% can be added. In addition, other conventional auxiliaries and additives can be used in the compositions according to the invention.

In the organic binder matrix of the intermediate layer of the laminate there is usually a flat structure embedded. In principle, a large number of materials can be used for this flat structure, examples being “nonwovens”, nonwovens, woven fabrics, knitted fabrics based on a large number of plastic fibers, such as polyester fibers, polypropylene fibers, polyamide fibers, carbon fibers or glass fibers. In a particularly preferred embodiment, these flat structures can consist of an expanded metal grid, a wire grid, a web plate or a perforated plate. Such metallic fabrics are for example from WO 00/13890 or known from DE-A-3935120. The ones mentioned there

Flat structures for intermediate layers of multilayer laminates are expressly part of this application.

The two outer metal sheets have a thickness between 0.1 and 0.5 mm, preferably between 0.2 and 0.3 mm. These sheets can be normal steel sheets, but also steel sheets that have been refined by the various galvanizing processes, here are the electrolytically galvanized, hot-dip galvanized sheets and the corresponding thermally post-treated or galvanized or subsequently phosphated steel sheets as well as aluminum sheets or magnesium sheets.

The laminate has a total layer thickness between 1 mm and 2 mm, preferably between 1.2 and 1.8 mm.

As mentioned at the beginning, the above-mentioned 1- or 2-component heat-curing adhesive / sealant compositions are used for the production of multilayer laminates, which are preferably used for the body-in-white in the automotive industry. The curing of the compositions should be in a temperature range between 80 and 240 ° C in about 10 to 35 minutes. , possibly in two stages. Temperatures between 160 and 200 ° C are preferably used in the shell. A decisive advantage of the compositions used according to the invention is that here too all advantages of the rubber-based adhesives / sealants known per se can be used, i.e. have good aging-resistant adhesion on various galvanized steels such as electrolytically galvanized, hot-dip galvanized and the corresponding thermally post-treated or galvanized and subsequently phosphated steel sheets, as well as non-galvanized steels and aluminum, even if the substrates are still provided with the various anti-corrosion and / or deep-drawing cavities.

The compositions used according to the invention have the following preferred compositions: % By weight Chemical name

3.0-10.0 ice 1, 4 polybutadiene, solid

3.0-8.0 zinc oxide

2.0-20 calcium oxide

0.1-2.0 2.2 methylene-bis- (4 methyl-6-tert-butylphenol)

0.5-5.0 Russ

0-2.0 hollow microspheres

5.0-40.0 calcium carbonate

5.0-40.0 calcium carbonate, coated with stearate

5.0-20.0 polybutadiene liquid, MW approx. 1800, ice - 1, 4 approx. 72%

5.0-30.0 polybutadiene with active carboxyl groups, MW approx. 1700

2.0-40.0 low molecular weight, sterospec. Polybutadiene oil, MW 1800, vinyl 50%

1, 0-10.0 sulfur

0.2-5.0 MBTS

2.0-10.0 EVA copolymer, Tg approx. 40 ° C

0-5.0 magnesium oxide

The invention is to be explained in more detail in the following exemplary embodiments, the selection of the examples not limiting the invention. should represent the object, they should only illustrate concrete exemplary embodiment in a model manner. Unless stated otherwise, all amounts are by weight for compositions.

Examples

Examples 1 to 3 below list the compositions of 3 rubber adhesives used in the manufacture of multilayer laminates.

Example 1 :

Structural rubber-based adhesive

3.75 ice 1, 4 polybutadiene, solid

4.00 zinc oxide

4.95 calcium oxide

0.50 2.2 methylene - bis - (4 methyl-6-tert.-butylphenol)

0.50 Russ

0.20 hollow microspheres

24.60 calcium carbonate

14.30 calcium carbonate, coated with stearate

13.50 polybutadiene liquid, MW approx. 1800, ice -1, 4 approx. 72%

10.00 polybutadiene with active hydroxyl groups, MW 2800

5.00 low molecular weight, sterospec. PB-ÖI, MW 1800, vinyl 50%

7.25 sulfur

0.95 MBTS

10.00 polyvinyl acetate, EVA copolymer, Tg approx. 40 ° C

0.50 imidazole

Example 2: Relining adhesive based on rubber

9.00 ice 1, 4 polybutadiene, solid

4.00 zinc oxide

4.95 calcium oxide

0.50 2.2 methylene - bis - (4 methyl-6-tert.-butylphenol)

3.00 conductivity black

21, 90 calcium carbonate

10.05 calcium carbonate coated with stearate

23.00 liquid polybutadiene, MW approx. 1800, ice -1, 4 approx. 72%

4.00 polybutadiene with active carboxyl groups, MW 1700

4.80 sulfur

4.80 MBTS

4.00 phenol novolak hexamine resin

6.00 talc

Example 3:

2-component system based on rubber according to the teaching of EP 356715

A component:

4.00 zinc oxide

4.55 calcium oxide

0.50 2.2 methylene - bis - (4 methyl-6-tert.-butylphenol)

0.50 Russ

7.00 alkyl sulfonic acid ester of phenol

0.50 polyether polyol

38.45 graphite

14.00 liquid polybutadiene, MW approx. 1800, ice -1, 4 approx. 72% 21, 00 polybutadiene with active hydroxyl groups, MW 2800

1, 00 hexamethylene bisthiosulfate

4.00 sulfur

4.00 MBTS

1,00 tetramethylene methylenediamine

Component B

6.00 zinc oxide

4.95 calcium oxide

0.50 2.2 methylene - bis - (4 methyl-6-tert.-butylphenol)

24.00 graphite

14.00 liquid polybutadiene, MW approx. 1800, ice -1, 4 approx. 72%

53.55 polybutadiene with active carboxyl groups, MW 1700

1, 00 hexamethylene bisthiosulfate

6.00 sulfur

4.00 MBTS

On the one hand, aluminum sheets and on the other, galvanized steel sheets (Elozink) with sheet thicknesses of 0.25 mm were used for the production of the multilayer laminates. For this purpose, the aforementioned adhesive was first applied to a sheet, then an expanded metal with a thickness of 0.25 mm was placed as a flat structure in accordance with the teaching of WO 00/13890 and then a second sheet was placed over it and the entire composite was pressed in such a way that the intermediate layer between the outer sheets had a layer thickness of approximately 0.25 mm. The composite was then for 30 min. cured at 180 ° C. The measurement results listed below were then determined.

Measurement results: Test Example 1 Example 2 Example 3 Aluminum

/ Elozink

(Comparison)

Tensile shear strength: (30 ^' 180 ° C) 12.5 MPa 2.2 MPa 1.50 MPa na

3 point bending test / mm

(Aluminum)

2mm 50 20 23 4

4mm 62 37 44 7

6mm 66 45 56 10

7mm 67 47 60 12

3 point bending test / mm

(Elozink)

2mm 68 42 16 6

4mm 81 52 33 11

6mm 85 58 45 15

7mm 87 60 50 17

Loss factor d as a function of the excitation frequency kHz structural adhesive according to example 1

1 kHz 3 kHz

Solid steel (reference): 0.01 0.02

Steel / steel with Example 1 0.075 0.16

Steel / aluminum with example 1 0.12 0.20

From the standard forces listed above (in N) of the three-point bending test according to DIN 53293 it can be seen that the strength and deformation properties provide excellent values when using all three adhesives. For comparison, a composite without gluing was used, in which the three layers of outer sheet metal / expanded metal were joined together by spot welding. From this it is clear that the strength and deformation properties of the multilayer laminates according to the invention are many times higher than without using the adhesive.

At the same time, the good acoustic properties of the laminates are documented by the loss factor d compared to normal single-layer solid steel.

Claims

Patent claims

1. Multi-layer laminate can be produced, from two outer metal sheets and an intermediate layer from a binder matrix and, if appropriate, a sheet-like structure incorporated in the binder, characterized in that the binder composition contains a vulcanizable rubber material based on at least one liquid elastomer with reactive groups.

2. Laminate according to claim 1, characterized in that at least one rubber is a liquid polyene from the group consisting of 1,2-polybutadiene, 1,4-polybutadiene, polyisoprene, polybutene, polyisobutylene, copolymers of butadiene and / or isoprene Is styrene and / or acrylonitrile, copolymers of acrylic acid esters with dienes, the molecular weight of the liquid polyene being in the range from 900 to about 40,000.

3. Laminate according to claim 2, characterized in that the liquid (s) polyene (s) additionally contains terminal and / or randomly distributed carboxyl groups, carboxylic acid anhydride groups, hydroxyl groups, amino groups, mercapto groups or epoxy groups as functional groups.

4. Laminate according to at least one of the preceding claims, characterized in that the binder additionally contains at least one solid rubber in an amount of 1.5 to 9% by weight, preferably 4 to 6% by weight, based on the total composition.

5. Laminate according to claim 4, characterized in that it contains one or more solid rubbers from the group cis-1, 4-polybutadiene, styrene-butadiene rubber, synthetic isoprene rubber, natural rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber , Butyl rubber, acrylic rubber contains.

6. Laminate according to at least one of the preceding claims, characterized in that the vulcanization system from 1% by weight to 15% by weight, preferably 5% by weight to 10% by weight of powdered sulfur, 2% by weight to 8% by weight, preferably 3% by weight to 6% by weight of organic accelerator and 1% by weight to 8% by weight, preferably 2% by weight to 6% by weight of zinc compounds, preferably zinc oxide, the% by weight based on the total composition.

7. Laminate according to at least one of the preceding claims, characterized in that the binder additionally thermoplastic polymer powder selected from vinyl acetate homo- or copolymer, ethylene vinyl acetate copolymer, vinyl chloride homo- or copolymer, styrene homo- or copolymer, (meth) acrylate - Homo- or copolymer or polyvinyl butyral or a mixture of two or more of these polymers, which have an average grain size of less than 1 mm, preferably less than 350 microns, most preferably less than 100 microns.

8. Laminate according to at least one of the preceding claims, characterized in that the binder system contains blowing agents selected from expandable hollow microspheres or from the group of organic blowing agents azo compounds, in particular azobisisobutyronitrile or azodicarbonamide, the nitroso compounds, in particular di-nitrosopentamethylenetetramine, the sulfohydrazides, in particular the 4,4'-oxybis (benzenesulfonic acid hydrazide), and the semicarbazides, in particular the p-toluenesulfonylsemicarbazide.

9. Laminate according to at least one of the preceding claims, characterized in that the binder system additionally contains fillers, expanded hollow microspheres, rheology aids, extender oils, adhesion promoters and / or anti-aging agents.

10. Laminate according to at least one of the preceding claims, characterized in that the two outer metal sheets have a thickness between 0.1 and 0.5 mm, preferably between 0.2 and 0.3 mm.

11. Laminate according to at least one of the preceding claims, characterized in that the fabric is an expanded metal mesh, a wire mesh, a web plate or a perforated plate.

12. Laminate according to claim 10, characterized in that the fabric has a thickness between 0.7 and 1, 2 mm, preferably of about 1 mm.

13. Laminate according to claim 9 to 11, characterized in that the fabric is in electrically conductive connection with the two outer sheets.

14. Laminate according to claim 9 to 12, characterized in that the total layer thickness of the laminate is between 1 mm and 2 mm, preferably between 1, 2 and 1, 8 mm.

Process for the production of a multilayer laminate according to claims 1 to 14, characterized by the following essential process steps a) applying a vulcanizable rubber composition according to at least one of claims 1 to 8 with the aid of a slot die or a roller applicator to a metal sheet, b) applying the sheet material to the rubber composition c) joining the second sheet of metal d) optionally pressing the composite to the predetermined distance e) curing the rubber adhesive layer by heating the composite to temperatures between 80 ° C and 250 ° C, preferably between 160 ° C and 200 ° C

6. Use of multi-layer laminates according to claim 15 for the production of lightweight parts for machine, vehicle or equipment construction, in particular for automobile construction.