DE3818479A1 - Composite material comprising a metal layer, an adhesion promoter and a polypropylene layer - Google Patents

Abstract

Described is a composite material comprising a metal layer, an adhesion promoter and a polypropylene layer. The adhesion promoter consists essentially of an epoxy resin based on bisphenol A. The polypropylene layer contains, in the mass, a graftable silane and also a peroxide as crosslinking agent, or has been treated at the surface which faces the metal layer with a mixture of graftable silane and peroxide. If the polypropylene layer contains crosslinking agent, it is possible - by setting the degree of crosslinking and through a glass fibre reinforcement of the polypropylene layer - to adapt the linear thermal expansion coefficient of the polypropylene layer to that of the metal layer in order that a bimetal effect may be avoided.

Description

The invention relates to a composite material containing one Metal layer, an adhesion promoter and a polypropylene layer according to the preamble of claim 1, a method its manufacture and the use of the composite material.

Under "composite material" in the sense of the present invention molded bodies with a defined spatial shape are understood, such as. External parts for automobiles etc., as well as flat, in essentially flat sheets or plates which are known as semi-finished products can be processed, e.g. by forming etc. to form bodies.

Materials made of fiber-reinforced polyolefins, especially here the known as "GMT" glass mat reinforced polypropy lene become molded parts on a technical scale, for e.g. Au tomobile and other technical applications, deformed. These The use of parts is limited by the quality of their parts Surface that does not require post-processing, such as sanding / filling, optically demanding surfaces, such as those found in Field of vision of automotive or other technical equipment len are required.

In DE-A-30 11 336 this difficulty is overcome proposed a composite of thin metal sheets from process composite materials into exterior parts of the body. If one relates this procedure to that in this publication not mentioned fiber composite combination glass fiber / polypropylene, this proves the extremely difficult liability to achieve between metal and plastic as a disadvantage.

From EP-A2-01 80 762 a bond between glasfa server-strengthened polyolefins and a metal layer over a mechanical adhesive bridge and with the help of a special butt  lyurethane adhesive known this method for connecting glass fiber reinforced polyolefins with metal layers is around of course and expensive.

The invention is therefore based on the object, composite work to provide materials and molded parts that meet the above requirements mentioned disadvantages do not have and with little effort and can be manufactured inexpensively.

The invention solves this problem with a composite material according to claim 1, preferably in connection with one or more ren of the features of claims 2 to 6. Preferred methods for the production of a composite material according to the invention in claims 7 to 11, preferred uses in the claims sayings 12 and 13 specified.

The use of epoxy resin is essential to the invention based on bisphenol A as an adhesion promoter and the An the presence of a graftable silane and a peroxide on the Surface or in the mass of the polypropylene used layer. This creates an unusually adhesive bond between the polypropylene layer and the metal layer enough that only by destroying the polypropylene layer can be separated.

Suitable adhesion promoters (primers) are low or high molecular weight epoxy resins based on bisphenol A, solvent-free or diluted to the desired viscosity with a suitable solvent, which are cured in particular with dicyandiamide or with acid anhydrides. After the metal sheet has been cleaned, the primer is applied in amounts of 1 to 10 g / m ² and subjected to a thermal treatment at 170 to 190 ° C. for 10 to 20 minutes. Here, the primer dries and hardens (level A), but it does not harden yet. The surfaces thus reserved are then fed directly either to the pre-composite or to the molded part production.

In addition to polypropylene, the polypropylene layer can also in particular other crosslinking agents, crosslinking accelerators, peroxide, sta bilisators and usual additives as well as glass fibers ten. can also mix with other thermoplastics beige will give as long as the characteristic properties not be affected too much, in particular can mix polypropylene with copolymers of propy lens with other olefinic monomers with 2 to 8 Koh atoms or other polyolefins such as e.g. Polybutenes, are used, but preferably at least 50% by weight homopolymeric polypropylene are included.

However, it has been found that the polypropylene is not can be replaced by polyethylene; this resulted in despite using the adhesion promoter according to the invention as well of a graftable silane and peroxide in polyethylene poor adhesion properties.

Metal layers come from aluminum, iron (steel) or their alloys in the thickness 0.1 to 1 mm, preferred as 0.3 to 0.6 mm, in question, the surfaces by Galvanizing, tinning, bondering, chromating or phosphating can be pretreated. Such metal sheets come in particular che, which is characterized by good forming behavior to draw.

A fiber-reinforced, especially glass fiber reinforced polypropylene used. Be The polypropylene layer preferably has 20 to 50% by weight of glass fa based on the weight of the fiber-reinforced polypropy layer on.

The glass fibers are preferably used in the form of glass fiber mats, nonwovens, lying or the like. They can have weights from 100 to 1200 g / m ² . One or more layers of glass fiber can be used for a reinforced polypropylene layer. In addition, mats, nonwovens or scrims made of mixed fibers, ie glass fibers and / or carbon fibers and / or thermoplastic fibers, such as polyester, polyether or polyimide fibers or similar high-temperature-resistant plastic fibers, can also be used.

Furthermore, colorants, stabilizers and conventional additives Impact of polyolefin processing in usual amounts are given.

According to a particularly preferred embodiment of the invention becomes a cross-linkable polypropylene as a polypropylene layer layer used during or after the composite Manufacturing is crosslinked. The networking is done by Use of a graftable silane compound and a peroxide, if necessary using a crosslinking accelerator.

As peroxides, individually or as a mixture, come dicumyl peroxide, tert -butylperoxy (3,5,5-trimethyl) hexoate, bis-C-tertiary-butyl peroxyisopropylbenzene in question. Here, 0.1 to 0.8%, based on the weight of the polypropylene used, organic peroxide with a one-minute half-life temperature from about 160 to 240 ° C used.

1.0 to 5%, based on the Ge importance of the polypropylenes and polyolefins used several alkoxisilane compounds of the formula

wherein R _{1 is} hydrogen or an alkyl radical with 1 to 4 carbon atoms, R _{2 is} a straight-chain alkylene radical with 1 to 10 carbon atoms, R _{3 is} an alkoxy radical with 1 to 5 carbon atoms, which can optionally be interrupted by an oxygen atom, and m and n = 0 or 1 are used, for example vinyl trialkoxysilane or γ- methacrylic-oxypropyl-trialkoxysilane, the latter is hereinafter referred to briefly as "MEMO".

In addition, a crosslinking aid such as Ver wetting accelerators, e.g. Dibutyltin dilaurate, in amounts up to 0.1% by weight, based on the weight of the poly used olefins.

With regard to the crosslinking of polypropylene, reference is made to DE-A- 33 27 149, DE-A1-35 30 364, DE-A1-25 17 256 and DE-A1-33 46 267 referred.

The combination of networking has been particularly positive and glass fiber reinforcement of polypropylene has been proven: Schend has shown that the under different achievable degree of crosslinking of the polyolefin and by adjusting the glass content, the linear temperature off change coefficient of expansion of the reinforced polypropylene layer and the linear expansion coefficient of the steel as well as that of aluminum. For example, a cross-linked, glass fiber reinforced polypropylene approach follows the composition

100.0 parts by weight of polypropylene, MFI [230/5] <0.1
0.4 parts by weight of dicumyl peroxide
1.2 parts by weight of γ- methacryl-oxypropyl-trimethoxysilane (MEMO)
0.5 parts by weight stabilizer for polypropylene
1.0 part by weight of carbon black

with 30 wt .-% glass fiber reinforcement a linear temperature expansion coefficient of 23 × 10 ^-6 / K (this corresponds to the expansion coefficient of aluminum) and with 40 wt .-% glass fiber content of 13 × 10 ^-6 / K (this corresponds to the expansion coefficient efficient of steel). Even with an asymmetrical structure of the composite material, the freedom from distortion can be achieved with temperature changes, since no "bimetal" effect occurs at the same temperature expansion coefficient of the metal layer and polypropylene layer. In comparison, a polypropylene without crosslinking with 30% by weight of glass fibers shows a linear expansion coefficient of 62 × 10 ^-6 / K and with 40% by weight of glass fibers of 50 × 10 ^-6 / K.

The adhesion promoter (primer) is during the manufacture of the Bond between the primed metal layer and that Polypropylene layer containing crosslinking agents still very much active and only hardens completely during this bond, so that the chemical reaction between silane, peroxide and Primer to connect such a strong bond between the two the layers is achieved that the composite only with destruction tion of at least one of the layers can be separated.

After the crosslinking of the polypropylene layer in the Composite material has an extremely high thermal resilience, the composite is special still above the crystallite melting point of the Po used lypropylene resilient, in particular a molded part from the Composite material according to the invention without delamination or Ver molding can be varnished at 180 to 200 ° C.

So far for the composite material according to the invention polypropylene layers are used that do not contain silane and peroxide ten, the surface of the polypropylene layer must be before the together press with the primed metal with a mixture of injectable silane, peroxide and possibly a crosslinking accelerator be pretreated. This will also make it extraordinary high bond strength of the composite is achieved, however Polypropylene layer not so high due to the lack of cross-linking temperature resistant; there is also no possibility of the linear Temperature expansion coefficient to be that of the metal layer fit.

So much for a cross-linkable and fiber-reinforced polypropylene layer is used, for example, by extrusion of sheets with a thickness of 0.3 to 3 mm at temperatures of 170 to 230 ° C, the mixture not yet ver wetting or a degree of crosslinking of <20% and preferably <5% and immediately after extrusion for penetration ner reinforcing mat is supplied, as in EP 01 34 941 and DE-PS 35 30 364 described.  

Another preferred method involves sprinkling the powdery polypropylene mixed with all for networking necessary additional components in the glass fleece and on closing melting and penetration between endless Tapes under pressure. In a variation of this can also be done by means of the above-mentioned extrusion the coating of the reinforcement kungsvlieses before pressing between endless belts consequences.

As a non-crosslinked fiber predominantly containing polypropylene Thick polypropylene layers usually come with 20 up to 45% by weight of fibers reinforced polypropylene and polypropy len copolymers, known under the generic term GMT, in Fra ge for surface pretreatment with graftable silane, Per oxide and possibly crosslinking accelerator are treated. The preferred reinforcing fibers are glass fibers.

According to a preferred process for producing the composite material according to the invention with crosslinked or crosslinkable polypropylene layer, the metal layer is coated with an adhesion promoter based on bisphenol A, which contains an amide or acid anhydride hardener, in amounts of about 1 to 10 g / m ² be coated and subjected to a thermal treatment at about 170 to 190 ° C for about 5 to 10 min. The crosslinkable, but not yet crosslinked polypropylene layer containing the crosslinking agent is then bonded to the metal layer provided with the adhesion promoter at pressures of more than 1 bar.

The metal layer can with or before coating the adhesion promoter according to a customary for metal or multi-stage deep drawing process at room temperature to a metal preform are deformed, after which this metal preform in one heated to 60 to 120 ° C, made of female and male standing mold is inserted and one or more on the required volumes of coordinated polypropylene blanks layer that heats to a temperature of 190 to 230 ° C are placed and by closing the mold with each other  be pressed and connected. Here, the curing of the Primer layer and the crosslinking of the polypropylene layer headed. The final crosslinking of the polypropylene layer can be accelerated by warm storage in a humid atmosphere will.

However, the metal layer is preferably continuous with the Polypropylene layer connected to a flat semi-finished product, whereby the bond between the polypropylene layer and the metal layer for example by means of a double belt press known per se he follows. The semi-finished product thus produced can then Forming into shaped bodies to be processed.

In a preferred method for producing a composite material according to the invention, the polypropylene layer of which contains no crosslinking agent, the metal layer is coated with an adhesion promoter based on bisphenol A, which contains an amide or acid anhydride hardener, in amounts of about 1 to 10 g / m ² and subjected to a thermal treatment at about 170 to 190 ° C for about 5 to 10 minutes. The polypropylene layer, which has been surface-treated with a mixture of graftable silane and peroxide, is then bonded to the metal layer provided with the adhesion promoter at pressures of more than 1 bar.

The metal layer can - as described - before Ver bund with the non-crosslinkable polypropylene layer to form a me tallformformteil be formed or as a flat endless material can be processed into a semi-finished product.

As far as a metal preform is used, which in a Press mold with the poly possibly containing a crosslinking agent Propylene layer is connected, the die or Molding tool on the side facing the polypropylene layer Have depressions corresponding to those from the polypropy stiffening ribs or desired thickness changes be shaped.  

Reinforced sections of the polypropylene can preferably be used layer by inserting additional parts into the mold or the molding tool are formed when pressing the Layers bonded firmly to the plastic layers, each not be deformed itself.

The flat sheets produced according to the invention, essentially flat sheets or plates (semi-finished products) are preferred Molded parts processed further by appropriate cuts of the composite material after preheating to 180 to 230 ° C in a metal deep-drawing press, the drawing stamp of 50 to 130 ° C, preferably 70 to 90 ° C is heated, who is deformed the.

In particular, it is envisaged that the multi-stage forming follows and in each case a reheating of the blanks to be formed he follows.

Both composite according to the invention can be used as cuts substances with crosslinking agents, but not yet full permanently cross-linked polypropylene layer as well as composite fabrics are used whose polypropylene layer crosslinks is free of funds.

The invention is illustrated below with the aid of several embodiments games as well as comparative examples and the drawing explained.

The figure shows a composite material according to the invention with the metal layer 1 , the primer (adhesion promoter) 2 and the glass fiber-reinforced polypropylene layer 3 .

example 1

An electrolytically chrome-plated, cold-rolled steel sheet with a thickness of 0.3 mm, with a hardness level B according to Euronorm with a thermal expansion coefficient of 13 × 10 ^-6 / K, is pre-cleaned and with a primer made from a low-molecular epoxy resin based Bisphenol A (epoxy resin DER-331, DOW Chemical), dicyandiamide as hardener and benzyldimethylamine as accelerator in a weight ratio of 120: 3: 1.5 coated with approx. 10 g / m ² and 8 min. dried at 170 ° C. A cross-linkable glass mat reinforced polypropylene layer of the following composition:

100.0 parts by weight of polypropylene, MFI 230/5 <0.1 (Novolen 1300 Z, BASF)
0.4 parts by weight of dicumyl peroxide
1.2 parts by weight of γ- methacrylic-oxypropyl-trimethoxy-silane (Dynasilan MEMO, Hüls Troisdorf AG)
0.5 parts by weight stabilizer for polypropylene
1.0 part by weight of carbon black
68.0 parts by weight of glass fibers in the form of a glass mat with 680 g / m²

is produced by plasticizing the polypropylene mass at a temperature of 210 ° C and penetrating the glass mat until it has a weight per unit area of 1700 g / m ² . One cut each of the primed metal sheet and the cross-linkable glass fiber-reinforced polypropylene layer are placed in a press mold and assembled in the press at 200 ° C. and a low pressure of 5 bar to form a composite material and removed after cooling. The composite panel thus produced can be brought repeatedly to 200 ° C without visible deformation or delamination. A layer separation at room temperature is practically not possible, see Table 1. The separation takes place either in glass mat reinforced polypropylene or by partial tearing of the steel sheet. The polypropylene layer had a degree of crosslinking of 43% and a coefficient of thermal expansion of 13 × 10 ^-6 / K.

Comparative Example 2

The primed steel sheet described in Example 1 is included an unreinforced, non-crosslinkable polypropylene EPDM film of the following composition:

55.0 parts by weight of polypropylene, MFI 230/5 <0.1
45.0 parts by weight of ethylene propylene diene rubber
1.0 part by weight of lubricant
0.5 parts by weight stabilizer for polypropylene
0.5 part by weight of carbon black

and a basis weight of 600 g / m ² in a press at 180 ° C and 5 bar. The separation of the composite is easily possible despite the use of a primer (Table 1).

Comparative Example 3

The primed steel sheet described in Example 1 is laminated with an unreinforced, non-crosslinkable polyethylene with a density of 0.952 g / m ^{2 and a} thickness of 1 mm as in Example 2. Adequate liability is not achieved (Table 1).

Comparative Example 4

A solution was applied to the polyethylene mentioned in Example 3 consisting of 2.5 parts by weight of toluene, 1.2 parts by weight of MEMO and 0.4 parts by weight of dicumyl peroxide applied and with the prep wrote primed steel sheet at 180 ° C and 5 bar ver presses. The superficial Ver wetting of the polyolefin did not lead to sufficient adhesion.

Comparative Example 5

The crosslinkable, glass mat reinforced mentioned in Example 1 Polypropylene was made with a steel sheet, which degreased was, but does not have a primer, in a press 200 ° C and a pressure of 5 bar laminated. The one achieved Adhesion was insufficient, sheet metal and plastic could be easily separate from each other.  

Comparative example 6

The primed steel sheet described in Example 1 is included a commercially available plate made of glass fiber reinforced homopolymer Polypropylene with a glass fiber content of 30 wt .-% and one Thickness of 2 mm as described in Example 1 pressed. The one there if liability was achieved, the separation was unsatisfactory between the two materials to be joined (Table 1).

Comparative Example 7

As described in Example 6, a composite with a co polymeric polypropylene with a glass fiber content of 30% by weight produced. Liability was also unsatisfactory (table 1).

Comparative Example 8

On the film made of polypropylene and a in Example 2 EPDM became a solution consisting of 2.5 parts by weight of toluene, 1.2 parts by weight of MEMO and 0.4 parts by weight of dicumyl peroxide added wear and with the above primed steel sheet 180 ° C and 5 bar pressed. The take place during the pressing The surface crosslinking of the polyolefin leads to a good adhesion (Table 1).

Examples 9 and 10

The glass mat reinforced mentioned in Examples 6 and 7 Polypropylene mats were superficial as in Example 8 Treated silane and peroxide and pressed at 200 ° C and 5 bar. Here too, the chemical reaction of the silane and Peroxide achieved good adhesion (Table 1).

Comparative Example 11

The procedure is as described in Example 1, but ent the glass mat reinforced polypropylene layer does not hold a MEMO. The liability of this peroxidically treated, but not over Silane crosslinkable composite material is unsatisfactory. Both Layers can be separated easily.  

Table 1

The following Examples 12 to 22 are intended to be inventive of the system epoxy resin based on bisphenol A and in bulk or superficially silane cross-linked fiber-reinforced polypropylene set out. As a glass mat reinforced polypropylene layer in the following Examples 12 to 18 ge in Example 1 named composition used.

The composite material is produced in the press as in example 1.

Example 12

A hot-dip galvanized steel sheet 0.8 mm thick was made with Per Chlorethylene degreased and a primer made from a low molecular weight bisphenol A resin as in Example 1, dicyandiamide as hardener and benzyldimethylamine as a weight ratio accelerator 130: 3: 1.5 plotted. After a brief hardening took place the fitting with the above-mentioned glass mat reinforced, crosslinkable polypropylene layer. The liability between the Layers and the temperature and temperature change resistance were very good (Table 2).

Comparative Example 13

The same steel sheet as in Example 12 was gum mimodified bisphenol A epoxy resin (Epoxy Resin XZ 86709, DOW Chemical), methyl tetrahydrophthalic anhydride (MTHPA) as Hardener and benzyldimethylamine as accelerators in the weight ratio Ratio 100: 70: 1 primed and after pre-curing at 180 ° C pressed as before. The liability achieved was unsatisfactory (Table 2). The affinity between the two to be connected Was evident from the rubber modification of the substrates Epoxy resin disrupted.

Comparative Example 14

The same steel sheet as in Example 12 was butted lyurethane-modified bisphenol A epoxy resin (Epoxy Resin XZ 86 701.01, DOW Chemical) with the same hardener / accelerator as coated in Example 11 in a weight ratio of 100: 50: 1 and with the above-mentioned glass mat-reinforced crosslinkable poly  propylene layer pressed. There was insufficient liability found (Table 2).

Example 15

The same steel sheet as in Example 12 was made high molecular bisphenol A epoxy (epoxy resin DER 652-A 75, DOW Chemical), 75% in acetone, with dicyandiamide and benzyldime thylamine primed in a weight ratio of 130: 3: 1.5, at 180 ° C. pre-hardened and pressed to the composite as described above. Adhesion as well as temperature and temperature changes durability was very good (Table 2).

Example 16

The procedure was as in Example 15, but an elec trolytically galvanized sheet of 0.8 mm thick. Adhesion and temperature resistance were excellent (Ta belle 2).

Example 17

The procedure was as in Example 15, but a cold was rolled thin sheet of 0.3 mm thickness is used. Liability and Tem temperature resistance was very good (Table 2).

Example 18

An electrolytically galvanized steel sheet with a thickness of 0.8 mm was after degreasing with a in propylene glycol mono Epoxy resin based on bisphenol A (epoxy Resin DER 652-PM-75, DOW Chemical) (25 parts by weight of epoxy resin), Dicyandiamide and benzyldimethylamine as hardeners and accelerators ger coated in a weight ratio of 130: 3: 1.5 and according to before hardening at 180 ° C with a layer of glass mat reinforced silane crosslinkable polypropylene pressed. Both liability and temperature resistance was also very good (Table 2).

Example 19

An aluminum thin sheet, thickness 0.2 mm, with a linear temperature expansion factor of 23 × 10 ^-6 / K, was degreased and with bromine-containing epoxy resin based on bisphenol A (epoxy resin DER-516, DOW Chemical), 75% in Methyl ethyl ketone, dicyandiamide as hardener and benzyldimethylamine as accelerator in a weight ratio of 130: 3: 1.5 primed and after pre-curing at 180 ° C with a layer of a glass mat reinforced, crosslinkable polypropylene of the following composition:

100.0 parts by weight of polypropylene, MFI 230/5 <0.1
0.4 parts by weight of dicumyl peroxide
1.2 parts by weight of MEMO
0.5 parts by weight stabilizer for polypropylene
1.0 part by weight of carbon black
42.8 parts by weight of glass fibers in the form of a glass mat with 600 g / m²

pressed. The adhesion as well as the temperature and tem Temperature independence was very good (Table 2). The butt The propylene composition has a linear expansion coefficient efficient adapted to that of the aluminum sheet, the crosslinking degree of the polypropylene layer was 45%.

Example 20

An aluminum sheet AlMg 5 Mn 63/44 with a thickness of 0.5 mm is like described in Example 12 with a glass mat reinforced, crosslinkable polypropylene layer according to Example 19 to the composite pressed fabric. Adhesion and temperature resistance were out drawn (Table 2).

Example 21

An aluminum sheet AlMn 1 Mg 161/03 with a thickness of 0.5 mm was as described in Example 12 with a glass mat ver strengthened, crosslinkable polypropylene layer according to Example 19 processed. Adhesion and temperature resistance of the composite material were very good (Table 2).

Example 22

A steel sheet as in Example 12 was degreased and with a high molecular epoxy resin based on bisphenol A, diluted in Weight ratio 75:25 with methyl ethyl ketone, MTHPA and benzyl treated dimethylamine in a weight ratio of 130: 3: 1.5, pre  hardens at 180 ° C and pressed as in Example 7. Liability and the temperature and temperature change resistance were very good (Table 2).  

Table 2

Example 23

A composite material produced according to Example 1 is called appropriate blank heated to 210 ° C in the annealing furnace and in a 1000 KN deep-drawing press, the stamp of which is 100 ° C was heated, inserted and with a drawing depth of 50 mm at egg A punch diameter of 150 mm is formed into the molded part. The layers of the molded part could only be separated under Zer malfunction, a multiple temperature change The change between room temperature to 200 ° C did not lead to delays mining.

Example 24

A composite material produced according to Example 12 is as in Example 23 described with a drawing depth of 60 mm in one Drawing die diameter of 150 mm formed into the molded part. Haf tion and temperature or temperature change resistance were like in example 23.

Example 25

A hot-dip galvanized steel sheet with a thickness of 0.3 mm is degreased and primed with a mixture of low molecular weight bisphenol A epoxy resin, dicyandiamide and benzyldimethylamine in a weight ratio of 130: 3: 1.5 and for approx. 5 min at 180 ° C pre-hardened. The sheet thus treated is deep-drawn 60 mm in the deep-drawing press described in Example 21 with a punch diameter of 150 mm, without heating it. This deep-drawn metal part was placed in a female / male mold, the female mold was precisely adapted to the contours of the molded part. A blank of glass mat reinforced, cross-linkable polypropylene with a weight per unit area of 2000 g / m ² and the composition as described in Example 1 was placed on the metal formed part and heated to 210 ° C. in an external oven, and the shaped part was placed by closing the patriot educated. In this case, the female and male were heated to 90 ° C. Both adhesion and temperature resistance were as in Example 23.

Example 26

A hot-dip galvanized steel sheet with a thickness of 0.3 mm is in one usual metal deep drawing press with a punch diameter of 150 mm 60 mm deep drawn. This metal deep-drawn part was made after Degreasing with the primer, as described in Example 25, be acts, pre-hardened at 180 ° C and with glass mat reinforced Polypropylene, as described in Example 25, processed. Haf tion and temperature resistance also showed good values.

Example 27

A hot-dip galvanized steel sheet with a thickness of 0.3 mm is degreased and primed with a mixture of low molecular weight bisphenol A epoxy resin, dicyandiamide and benzyldimethylamine and pre-hardened for approx. 5 min at 180 ° C. The sheet treated in this way is deep-drawn 60 mm in the deep-drawing press described in Example 23 with a punch diameter of 150 mm, without heating it. This deep-drawn metal part was inserted into a female / male mold, the female mold was precisely adapted to the contours of the molded part. On the metallic formed part was heated to 210 ° C in an external oven to cut from non-crosslinkable glass mat-reinforced polypropylene with a basis weight of 2200 g / m ² , which, as described in Example 8, containing a mixture containing silane, peroxide and crosslinking accelerator was pretreated, placed on it and the molded part was formed by closing the male die. In this case, the female and male were heated to 90 ° C. Adhesion and temperature resistance up to 150 ° C were both good.

Example 28

A hot-dip galvanized steel sheet with a thickness of 0.3 mm is in one usual metal deep drawing press with a punch diameter of 150 mm 60 mm deep drawn. This metal deep-drawn part was made after Degreasing with the primer, as described in Example 25, be acts, pre-hardened at 180 ° C and with uncrosslinked glasmat reinforced polypropylene, as described in Example 25, processed. Adhesion and temperature resistance just showed if good values.

Claims (13)

1. Composite material containing a metal layer, an adhesion promoter and a polypropylene layer, characterized in that

• - That the coupling agent consists essentially of an epoxy resin based on bisphenol A.
• - And that the polypropylene layer
  • - Contains a graftable silane and a peroxide as crosslinking agent and / or
  • - Was treated on its surface facing the metal layer with a mixture of graftable silane and peroxide.

2. Composite material according to claim 1, characterized in that that the polypropylene layer is fiber reinforced. 3. Composite material according to claim 2, characterized in that that the polypropylene layer 20 to 50 wt .-% glass fibers contains. 4. Composite material according to one of claims 1 to 3, characterized characterized in that the polypropylene layer is cross-linked and a degree of crosslinking greater than 30%, measured than that in boiling decalin insoluble portion of the poly used propylene. 5. Composite material according to claims 3 and 4, characterized ge indicates that the glass fiber content and the crosslinking degrees are chosen so that the linear expansion coefficient the fiber-reinforced, cross-linkable polypropylene layer approximately the linear expansion coefficient of the Corresponds to the metal layer. 6. Composite material according to one of claims 1 to 5, characterized characterized in that the adhesion promoter with an amide or acid anhydride hardener is cured.   7. A method for producing a composite material according to one of claims 1 to 6, characterized in that

• - That the metal layer with the adhesion promoter based on bisphenol A, which contains an amide or acid anhydride, coated in amounts of about 1 to 10 g / m ² and a thermal treatment at about 170 to 190 ° C for about 5 to 10 min is subjected to and
• - That then a crosslinking agent containing, crosslinkable, but not yet crosslinked polypropylene layer is connected at pressures of more than 1 bar with the metal provided with the coupling agent.

8. A method for producing a composite material according to one of claims 1 to 6, characterized in that

• - That the metal layer with the adhesion promoter based on bisphenol A, which contains an amide or acid anhydride, coated in amounts of about 1 to 10 g / m ² and a thermal treatment at about 170 to 190 ° C for about 5 to 10 min is subjected to and
• - That then the surface treated with a mixture of graftable silane and peroxide treated polypropylene layer at pressures of more than 1 bar is connected to the metal provided with the adhesion promoter.

9. The method according to any one of claims 7 or 8, characterized ge indicates that the metal layer before or after loading layering with the bonding agent after one for metal usual single or multi-stage deep drawing process in space temperature is formed into a metal preform where after this metal preform in a to 60 to 120 ° C. heated die, consisting of female and male is inserted and one or more, on the required Vo lumen tailored blanks of the polypropylene layer, the are heated to a temperature of 190 to 230 ° C  placed and ver by closing the mold together presses and be connected, the curing of the Pri layer and possibly the crosslinking of the polypropylene shift is initiated. 10. The method according to claim 9, characterized in that the Press mold or the mold on which the polypropylene layer facing side depressions, correspond rip stiffening from the polypropylene layer pen or desired thickness changes can be formed. 11. The method according to any one of claims 9 or 10, characterized ge indicates that reinforced sections of the polypropy layer by inserting additional parts into the mold or the molding tool are formed during the pressing of the layers bonded firmly to the plastic layers but not deformed itself. 12. Use of a composite material according to one of the claims che 1 to 6 for the production of molded parts, where correspond appropriate cuts of the composite material after preheating to 180 to 230 ° C in a metal deep drawing press, the Drawing stamp to 50 to 130 ° C, preferably 70 to 90 ° C is heated, to be formed. 13. Use according to claim 12, characterized in that the transformation takes place in several stages and one re-heating each cut to be formed.