EP2951258A1

EP2951258A1 - Method for producing a metal-plastic hybrid component

Info

Publication number: EP2951258A1
Application number: EP14702233.9A
Authority: EP
Inventors: Maximilian Gruhn; Karl Kuhmann; Martin Risthaus
Original assignee: Evonik Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2013-01-29
Filing date: 2014-01-29
Publication date: 2015-12-09
Also published as: US20150361304A1; EP2951259B1; BR112015017978A2; BR122021018679B1; US10603872B2; JP2016506882A; JP2016510270A; JP6133440B2; CN105229107A; CN105229107B; KR20150113967A; KR101840099B1; CN105308144A; US20150375478A1; BR122021018633B1; EP2951259A1; BR112015017991A2; KR20150113966A; EP2759580A1; WO2014118210A1

Abstract

The invention relates to a method for producing a hybrid component comprising metal and plastic. The method comprises the steps: a) pre-treating the metal surface by the application of at least one conversion coating; b) applying at least one layer of an adhesion promoter composition and c) bonding the metal to the plastic. The adhesion promoter composition contains at least one copolyamide-based hot-melt adhesive.

Description

Process for producing a metal-plastic hybrid component

The present invention relates to a method for producing a hybrid component comprising metal and plastic, a coating for hybrid components and their

Use, hybrid components and metal substrates.

Hybrid components (also structural components) are composites of the two materials metal and plastic. They can be produced by the injection molding process. Hybrid components are components that are used, inter alia, in vehicle construction and in the automotive industry

Aircraft construction and in electronics and electrical engineering in the field of load-bearing parts, force-absorbing parts or as part of the housing, eg. For decorative purposes, are used. They are characterized in particular by the fact that they have local reinforcements, which give the component special mechanical properties, and / or offer the possibility for functional integration. Particularly noteworthy is the increase in component stiffness with additional

Weight reduction compared to previously used components in

conventional construction. In the aforementioned fields of application, hybrid components are increasingly being used in order to reduce the mass while at the same time optimizing the mechanical properties

To get properties. The disadvantage of these hybrid components lies in the lack of or insufficient adhesion between metal and plastic. In this respect, mechanical anchoring of the plastic to the metal has hitherto been carried out.

The adhesion between metal and plastic can be improved by adhesion promoters. From EP-A-1808468 and EP-A-2435246 hybrid components are known, wherein metal and plastic are connected by hot melt adhesives as adhesion promoters on copolyamide base, which additionally contain isocyanate and epoxide groups. Especially in the automotive industry metal substrates are known which

Conversion layers include, which are used for surface treatment. The layers are formed, for example, by phosphating or

Chromating on the surface.

The hybrid components of the prior art currently have between metal and plastic not yet sufficient liability to meet the requirements of mass production, for example in the automotive sector. The

Inadequate adhesion, for example, in the incompatibility of many plastics to various metals or in the varying chemical and physical

To see the nature of the substrate surfaces, which arise due to oxidation and corrosion processes due to environmental or media influences. The object was therefore to provide a new method that does not have the disadvantages of the prior art. Accordingly, the hybrid components obtainable from the process should have an improved or increased adhesion between metal and plastic compared with the prior art. In addition, the hybrid components obtained should meet the requirements of vehicle and aircraft construction as well as the electronics and electrical engineering industry. In addition, a good weather resistance, in particular corrosion protection resistance should be given. Metal and plastic of the hybrid component should be materially bonded

be connected to each other. Accordingly, a method of the type mentioned has been found, whereby hybrid components can be provided, which have improved adhesion between metal and plastic. The method according to the invention comprises the steps a. Pretreatment of the metal surface by applying at least one conversion layer,

b. Applying at least one layer of a primer composition and

c. Bonding the metal to the plastic, wherein the primer composition contains at least one copolyamide-based hot melt adhesive.

In the method according to the invention, the metal surface is first pretreated over the whole area or partially. The metal can be cleaned before pretreatment or already have metallic protective coatings. The metal cleaning is known in the art.

The pretreatment can be done with conversion means. The conversion agents are usually used as aqueous solutions. Conversion agents are commercially available passivants and products for the

Conversion treatment in question, such as zinc phosphating agents, iron phosphating and phosphoric acid solutions containing titanates or zirconates. Chromating agents are also technically possible, but they are less preferred because of their health-endangering properties.

Conversion agents preferably contain halides. As halides, salt-like, covalent and complex compounds of the halogens fluorine, chlorine, bromine and iodine with more electropositive elements are considered, with salt-like halides, complex halides or mixtures of these halides are preferred. Halogens are salt-like substances of alkali and alkaline earth salts and ammonium salts of hydrohalic acids. In the complex halides, halogen ions occur as monodentate anionic ligands. Further preferred are fluorine-containing halides. Particularly preferred salt-like fluorine-containing halides are fluoride anions or hydrogen fluoride anions, for example hydrogendifluoride.

In the complex halides, preferably subgroup elements, preferably titanium or zirconium, form the central atom. Complex halides are included, for example, hexafluorotitanate anions, hexafluorozirconate anions or

Mixtures thereof.

The complex halides are preferably in a proportion of 0.2 to 10 wt .-%, preferably 0.5 to 8 wt .-%, based on the total weight of the aqueous

Conversion agent solution, included. Suitable conversion agents are sold, for example, by the company Henkel, Germany, under the name Granodine. The salt-like halides are preferably contained in a proportion of 10 to 300 ppm, preferably 20 to 200 ppm and particularly preferably 30 to 100 ppm, each based on the total weight of the conversion agent solution.

Fluoride-containing solutions containing fluoride and hydrogen difluoride are

for example, under the name Grano Toner 38 offered by Henkel.

To prepare the conversion layer, the metal can be immersed in the conversion agent. In addition, the conversion agent can be applied by means of spraying, knife coating, rolling, pressing, dipping, rolling, pouring or laminating.

Post-passivation can be carried out after the pretreatment. This is understood to mean a passivating rinse with acidic solutions, preference being given to using the abovementioned halides. Furthermore, the conversion layer can be obtained by a

flame pyrolytic deposition of amorphous silicate on the metal surface. The surface to be treated is passed through the oxidizing region of a gas flame into which a silicon-containing substance, the precursor, is metered. This burns and the residue separates as an amorphous silicate as firmly adherent

Layer in layer thicknesses of about 20 to 40 nm on the surface from.

In order to treat a surface, a plasma jet is generated from a working gas or a flame jet is swept out of a fuel gas, wherein at least one precursor material is supplied to the working gas and / or the plasma jet or the fuel gas and / or the flame jet and in the plasma jet or flame jet is reacted, wherein at least one reaction product of at least one of the precursors on the surface and / or deposited on at least one disposed on the surface layer. Such a method is described, for example, in DE-A-102009042103.

The treatment of the surface can be done at atmospheric pressure. In addition, optical emissions of the plasma jet or flame jet can be measured by means of a spectrometer, on the basis of which the characteristics of the plasma jet or flame jet are determined.

The treatment of the surface may consist in an activation or in a coating of the surface by means of the plasma jet or flame jet.

In particular, the throughputs of working gas and precursor are independent

controllable from each other and / or regulated. In addition to the distance of the plasma source to the surface to be coated so is another means for influencing the layer properties, such as the layer thickness or the refractive index, available. Likewise, gradient layers can be realized in this way. By suitable choice of these process parameters and the precursors used are, for example, the following properties of the surface of the substrate targeted

changeable: scratch resistance, self-healing ability, barrier behavior,

Reflection behavior, transmission behavior, refractive index, transparency,

Light scattering, electrical conductivity, antibacterial behavior, friction, adhesion, hydrophilicity, hydrophobicity, oleophobicity, surface tension, surface energy, anti-corrosive effect, dirt-repellent effect, self-cleaning ability, photocatalytic behavior, anti-stress behavior, wear behavior, chemical resistance, biocidal behavior, biocompatible behavior, electrostatic behavior, electrochromic Activity, photochromic activity, gasochromic activity.

The generation of the plasma can be done in a free-jet plasma source. In this method, a high-frequency discharge between two concentric electrodes is ignited, which is formed by an introduced gas flow

Hollow cathode plasma as Plasmajet from the electrode assembly usually several centimeters in the free space and is led out to be coated surface. The precursor can be introduced both before the excitation in the working gas (direct plasma processing) and then in the already formed plasma or in the vicinity (remote plasma processing). Another possibility of plasma generation is the exploitation of a dielectrically impeded discharge.

In this case, serving as a dielectric working gas, in particular air, passed between two electrodes. The plasma discharge takes place between the electrodes, which are supplied with high-frequency high voltage. The precursor is preferably introduced in the gaseous state or as an aerosol into the working gas or the plasma stream. Liquid or solid, in particular pulverulent precursors can also be used, but are preferably converted into the gaseous state before introduction, for example by evaporation. Likewise, the precursor can first be introduced into a carrier gas, entrained therefrom, and introduced together with it into the working gas or the plasma stream. The deposited layer preferably comprises at least one of silicon, silver, gold, copper, iron, nickel, cobalt, selenium, tin, aluminum, titanium, zinc, zirconium, tantalum, chromium, manganese, molybdenum, tungsten, bismuth, germanium, niobium , Vanadium, gallium, indium, magnesium, calcium, strontium, barium, lithium,

Lanthanides, carbon, oxygen, nitrogen, sulfur, boron, phosphorus, fluorine,

Halogens and hydrogen. In particular, the layers contain oxidic or / and nitridic compounds of silicon, titanium, tin, aluminum, zinc, tungsten and zirconium. The precursor used is preferably an organosilicon and / or an organo-titanium compound, for example hexamethyldisiloxane, tetramethylsilane,

Tetramethoxysilane, tetraethoxysilane, titanium tetraisopropylate or titanium tetraisobutylate.

In this way, for example, barrier layers can be realized that the

Reduce permeability to gases and water.

As the working gas, air, steam or other gas can be used, for example, oxygen, nitrogen, noble gases, hydrogen, carbon dioxide, gaseous hydrocarbons or a mixture thereof.

For example, propane can be used as the fuel gas for the flame treatment, air or oxygen being supplied for combustion. The fuel gas can be premixed with air or oxygen. Also, the mixing ratio between fuel gas and oxygen or air can be used as a parameter based on the determined

Characteristics are controlled and / or regulated.

The generation of the plasma can take place in a free-jet plasma source or by means of dielectrically impeded discharge. The precursor is preferably introduced in the gaseous state or as an aerosol into the working gas or the plasma stream. Liquid or solid, in particular pulverulent precursors can also be used, but are preferably converted into the gaseous state before introduction, for example by evaporation. Likewise, the precursor can first be introduced into a carrier gas, entrained therefrom, and introduced together with it into the working gas or the plasma stream.

The precursor used is preferably an organosilicon and / or an organo-titanium compound, for example hexamethyldisiloxane, tetramethylsilane,

In a preferred embodiment, a first layer having a barrier effect and then at least one further layer as a functional layer. After drying the conversion layer, the adhesion promoter composition is then applied over the entire surface or partially to the metal or the conversion layer. The metal with the applied primer composition is thermally crosslinked or dried, with object temperatures of 120 ° C to 240 ° C, preferably 150 ° C to 225 ° C, preferably 175 ° C to 200 ° C, for a period of 0, 5 min to 30 min, preferably from 1 min to 20 min, preferably 3 min to 10 min, are advantageous. The person skilled in the art can determine suitable time / temperature conditions by means of preliminary tests. In rolling processes, peak metal temperatures (PMT) of 180 ° C to 230 ° C are preferred. The expert is the realization of the PMT

Set system or belt speed accordingly.

The compositions are thus thermally cured.

The compositions can be continuous or discontinuous by means of

Electrocoating, electrostatic spraying, vortex sintering, rolling (for example coil coating), casting, spraying and spraying, laminating, (hot) pressing, (Co) extrusion, with spray methods and roller application methods being preferred. In this case, the compositions according to the invention can be applied on one or both sides, locally or over the entire surface. The baked layer thicknesses (dry layer thicknesses) of the adhesion promoter compositions may be from 10 to 1000 μm, preferably from 20 to 250 μm and preferably from 30 to 150 μm. in the

Roller processes are layer thicknesses of 5 μιτι to 250 μιτη, in particular 10 μιτι to 50 μιτη, preferably.

Thereafter, the plastic is applied, for example, by an injection molding process or by hot pressing on the metal and the metal physically and / or chemically connected to the plastic. Preferably, the plastic is by means of

Injection molding technology injected. For this purpose, the coated metal part is inserted into the injection mold and back-injected after closing the tool with the plastic. Upon contact of the plastic melt with the coated metal surface forms a cohesive bond or the adhesion between the components. The cohesively connected hybrid component can then be removed from the injection mold and further processed or processed.

Subsequently, the combination of metal and plastic for 2 min to 90 min, preferably 5 min to 60 min, at 150 ° C to 230 ° C to increase

Bonding adhesion and degree of crosslinking are subjected to a heat treatment.

As a result, a cohesive composite of the plastic is achieved to the metal.

Hybrid components produced in this way have a permanent connection between the pretreated and coated metal and the plastic and show a high mechanical and dynamic load capacity.

Suitable metals are, for example, iron-containing alloys such as steel, aluminum, copper, magnesium, titanium and alloys of the aforementioned metals. Preferred metals are steel, titanium, aluminum and alloys of the aforementioned metals, more preferably steel and aluminum and aluminum alloys. Preferred steels are unalloyed steels or stainless steels. Steels with a protective coating are particularly preferred. Suitable coatings are, for example, coatings of zinc, aluminum-silicon, aluminum-zinc, zinc-aluminum, zinc-iron or zinc-magnesium, aluminum-silicon, zinc-aluminum and zinc being preferred. The composition of the coatings is defined, for example, in the brochure "Schmelztauchveredelt.es Band and Blech" of the Stahl-Informations-Zentrum in the Stahl-Zentrum, Düsseldorf, Germany, 2010 edition. Before the application of the plastic, the coated metal can be trimmed, reshaped or deformed The deformation or deformation can take place before or after the application of the abovementioned compositions.

The application of the plastic to the coated metal can in a known manner, for. Example, by injection molding, pressing, laminating, injection molding or (co) extruding done. Preferably, the plastic is injected by means of injection molding technology. The metal provided with the coatings according to the invention may be preheated in a range from 50 ° C to 250 ° C in order to maintain the temperature in the contact area with the plastic, e.g. when over-molding or coextruding for a good bond between primer and plastic.

Suitable plastics contain e.g. Polybutylene terephthalates, polyolefins,

Polycarbonates, polyurethanes, aliphatic or partially aromatic polyamides,

Plastic mixtures containing polyamides, styrene polymers such as acrylonitrile-butadiene-styrene, polyalkyl (meth) acrylates such as polymethyl methacrylate and mixtures of the aforementioned plastics. Blends of polycarbonates and acrylonitrile-butadiene-styrene are also suitable. Preference is given to aliphatic or partially aromatic polyamides, mixtures of plastics containing polyamides, polybutylene terephthalates, polyolefins and mixtures of the abovementioned plastics, with polyamides being particularly preferred. The plastics are preferably reinforced (Reinforcing), for example, fiber-reinforced, with glass fiber (GF) or

carbon fiber reinforced (CF) plastics are preferred. In addition, the

Plastics contain fillers such as talc or chalk. The plastics may further contain additives such as stabilizers, impact modifiers, flow aids and pigments.

Preferred polyamides (PA) are selected from the group consisting of

Polyamide 6, polyamide 6.6, polyamide 610, polyamide 612, polyamide 613, polyamide 614, polyamide 106, polyamide 1010, polyamide 1012, polyamide 1212, polyamide 1 1, polyamide 12, polyphthalamides or blends based on these polyamides. Particularly preferred polyamides are selected from polyamide 6, polyamide 6.6, polyamide 610, polyamide 1010 and mixtures thereof. The polyamides preferably contain reinforcing agents. Another object of the invention is a coating for hybrid components, comprising at least one conversion layer and at least one layer of the aforementioned adhesion promoter composition (adhesion promoter layer). The coating is obtainable by the method according to the invention. The coatings according to the invention can be used as adhesion promoters between metal and plastic of a hybrid component.

Another object of the invention are hybrid components, wherein the metal is connected to the plastic at least by a coating according to the invention. The hybrid components according to the invention are used, for example, in mechanical and plant engineering, vehicle construction, in the aerospace industry, in rail construction, in electronics or in electrical engineering. Typical applications are in the area of

Automotive interiors, bumpers, load-bearing body structures, as frame and body panels such as front end girders, door, roof, floor or

To find suspension components or as electronics housing. Frames, profiles, Facade elements or guide rails of windows and doors in the field of house construction and architecture are also suitable areas of application.

Another object of the invention is a metal substrate which is coated with at least one coating according to the invention. The substrate may, for. B. be a metallic semi-finished or a metallic molding. The substrate is

preferably a metal band, a metal panel, a metal profile, a metal casting or a metal wire. Primer composition

The primer composition contains at least one copolyamide-based hot melt adhesive. The primer composition may be in solution, in dispersion or as a solid. The hotmelt adhesive contains at least one copolyamide. The copolyamide can be prepared from amide monomers and comonomers. The comonomers preferably give copolyamides which have a melting point between 95 ° C. and 175 ° C. The amide monomers are preferably selected from the group consisting of laurolactam, amionoundecanoic acid or mixtures thereof. Copolyamides based on laurolactam are particularly preferred.

The comonomers are preferably selected from aliphatic or

cycloaliphatic diamines, aliphatic or cycloaliphatic dicarboxylic acids, lactams and mixtures thereof. The comonomers contain, independently of each other, preferably 4 to 18 C atoms. Suitable dicarboxylic acids are, for example, adipic acid, sebacic acid or dodecanedioic acid. Examples of suitable diamines are hexamethylenediamine, decamethylenediamine or

Dodecamethylenediamine. Lactams such as caprolactam can also be used as Comonomer can be used.

Preferred comonomers are caprolactam and a polymer of adipic acid and hexamethylenediamine, preferably in a mass ratio of 1: 1.

An excess of amine groups of the diamines results in copolyamides having reactive amino end groups.

The copolyamides preferably have amine numbers of 75 to 400 mmol / kg.

The weight-average molecular weight of the copolyamides is preferably found in a range of 15,000 to 70,000 g / mol (measured by means of

Gel permeation chromatography (GPC) against a polystyrene standard). The relative solution viscosity is preferably 1.2 to 1.8 (determination according to ISO 307).

The copolyamides or the hotmelt adhesive can be used in the inventive

Compositions can be used in solution, in dispersion or in powder form, with the powder form being preferred. A suitable solvent is, for example, m-cresol.

The powder form can be obtained for example by grinding, wherein the grain diameter is preferably <200 μιτι, preferably <100 μιτι and particularly preferably <70 μιτι (sieve analysis). In a preferred embodiment of the invention, at least one epoxide component and at least one blocked polyisocyanate are added to the copolyamide as further constituents of the hot-melt adhesive.

Typically, the epoxy component has an epoxy index of 1-2 Eq / kg. The epoxide equivalent weight of the epoxy resins used may be between 400 to 4000 g / mol, preferably 700 to 3000 g / mol and preferably between 875 and 1000 g / mol lie (determined by SMS 2026).

The proportion of OH groups of suitable epoxy resins is preferably from 2000 to 4500 mmol / kg, preferably from 2300 to 4000 mmol / kg (method SMS 2367).

For example, compounds based on diols, polyols or dicarboxylic acids can be used as the epoxide component, diols being preferred and corresponding phenol-diol derivatives being particularly preferred. Very particularly preferred phenol-diol derivatives are bisphenols, in particular bisphenol A. The epoxide component is usually obtained by reaction with epichlorohydrin.

Suitable epoxy resins have a density of 1 to 1.3 kg / L, preferably 1.15 to 1.25 kg / L (25 ° C, determined according to ASTM D792). The glass transition temperature (Tg) may be 20 ° C to 100 ° C, preferably 25 ° C to 90 ° C, preferably 40 ° C to 60 ° C and more preferably 45 to 55 ° C (determined according to ASTM D3418). Of the

Melting range is usually in the range of 45 ° C to 150 ° C (according to DIN 53181). Suitable epoxide resins are known, for example, as EPIKOTE Resin, such as EPIKOTE Resin 1001 or 1009 from Hexion Specialty Chemicals, Inc.

available.

The hotmelt adhesive preferably contains the epoxide component in a proportion of 2.5 to 10% by weight, preferably 4 to 6% by weight, in each case based on the total weight of the hotmelt adhesive. The hot-melt adhesive furthermore comprises hardeners such as dicyandiamide (DCD), preferably in proportions of from 3 to 6% by weight, based on the total weight of epoxy resin. Hardening derivatives such as monuron or fenuron can be added for curing acceleration, whereby the curing temperatures can be lowered or the curing times can be shortened. The proportion of blocked polyisocyanate is preferably 2.5 to 15 wt .-%, preferably 4 to 6 wt .-%, each based on the total weight of

Melt adhesive. The blocked polyisocyanate component may be aromatic, aliphatic or

cycloaliphatic, with aliphatic or cycloaliphatic polyisocyanates being preferred. Blocking agent for isocyanates such as oximes, phenols or

Caprolactam are known in the art. Preferably lies the

Polyisocyanate component as uretdione to be blocked. Typical examples are sold under the name VESTAGON by Evonik Industries, Germany.

The adhesion promoter composition may contain self-crosslinking or externally crosslinking binders (for the term "binder", see Rompp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, Binders, pages 73 and 74) Within the scope of the present invention The term "self-crosslinking" refers to the property of a binder to undergo crosslinking reactions with itself, provided that the binders contain complementary reactive functional groups that react with each other to crosslink, or that the binders contain a reactive functional group On the other hand, such binder systems are referred to as externally crosslinking, in which one type of the complementary reactive functional groups is present in the binder, and the other type in a hardener or crosslinking agent Printing inks, Georg Thieme Ve rlag, Stuttgart, New York, 1998, Hardening, pages 274 to 276, especially page 275, below.

The primer composition may further include electrically conductive materials selected from graphite, carbon black, zinc dust, or mixtures of these materials, thereby forming electrically conductive primer compositions. The hybrid components comprising coatings of electrically conductive adhesion promoter compositions can be provided with a cathodic dip coating (KTL).

The primer composition may further contain organic solvents. Accordingly, the hot melt adhesive may be in solution or as a dispersion. Suitable solvents are polar or non-polar organic solvents.

Mixtures of polar and nonpolar solvents can also be used.

The primer compositions may further contain colorants, preferably pigments. In addition, functional pigments such as

Contain anticorrosive pigments.

Suitable hotmelt adhesives are available, for example, from Evonik Industries, Germany, under the name VESTAMELT. For example, the types X1027-P1, X1038-P1, X1316-P1 and X1333-P1 may be mentioned. In addition to the hot-melt adhesive, graft copolymers of polyamine and polamide-forming monomers such as lactams or co-aminocarboxylic acids may also be present, as described in EP1065236A2:

In the graft copolymer, the amino group concentration is preferably in the range of 100 to 2,500 mmol / kg.

As a polyamine, for example, the following classes of substances can be used:

- Polyvinylamine (Rompp Chemie Lexikon, 9th edition, Volume 6, page 4921, Georg Thieme Verlag Stuttgart 1992); - Polyamines, which are made of alternating polyketones (DE-OS 196 54 058);

- Dendrimers such as

((H2N- (CH 2) 3) 2 N - (CH 2) 3) 2 -N (CH 2) 2 -N ((CH 2) 2 -N ((CH 2) 3 -NH ₂ ) 2) 2

(DE-A-196 54 179) or

Tris (2-aminoethyl) amine, N, N-bis (2-aminoethyl) -N ', N'-bis [2- [bis (2-aminoethyl) amino] ethyl] -1, 2-ethanediamine,

3,15-Bis (2-aminoethyl) -6,12-bis [2- [bis (2-aminoethyl) amino] ethyl] -9- [2- [bis [2-bis (2-aminoethyl) amino] ethyl ] amino] ethyl] 3,6,9,12,15-pentaazaheptadecane-1,17-diamine (JM Warakomski, Chem. Mat. 1992, 4, 1000-1004);

- Linear polyethyleneimines which can be prepared by polymerization of 4,5-dihydro-1, 3-oxazoles and subsequent hydrolysis (Houben-Weyl, Methods of Organic Chemistry, Volume E20, pages 1482-1487, Georg Thieme Verlag Stuttgart, 1987) ;

branched polyethyleneimines which are obtainable by polymerization of aziridines (Houben-Weyl, Methods of Organic Chemistry, Volume E20, pages 1482-1487, Georg Thieme Verlag Stuttgart, 1987) and which generally have the following amino group distribution:

25 to 46% primary amino groups,

30 to 45% secondary amino groups and

16 to 40% tertiary amino groups.

The polyamine in the preferred case has a number average molecular weight M _n of at most 20,000 g / mol, more preferably of at most 10,000 g / mol and

particularly preferably of not more than 5,000 g / mol. Lactams or ω-aminocarboxylic acids which are used as polyamide-forming monomers contain 4 to 19 and in particular 6 to 12 carbon atoms. Particular preference is given to using ε-caprolactam and laurolactam or the associated co-aminocarboxylic acids. The molar ratio C12 / C6 building block is preferably between 4: 1 to 1: 4. The mass ratio of hot melt adhesive to graft copolymer is preferably between 19: 1 and 1: 1.

The functionalized polyolefin is in the simplest case polypropylene-based. But are also suitable Etylen / C3 to Ci2-α-olefin copolymers. For example, propene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene or 1-dodecene are used as C 3 - to C 12 -alpha-olefin. Furthermore, the ethylene / C3 to C12 α-olefin copolymers may also contain up to about 10 wt .-% maximum of olefin loci such as ethylidenenorbornene or 1, 4-hexadiene. As functionalization serve preferably

Acid anhydride groups, which in known manner by thermal or radical reactions of the main chain polymer with an unsaturated

Dicarboxylic anhydride or an unsaturated dicarboxylic acid are introduced. Suitable reagents are, for example, maleic anhydride or

Itaconic. In this way, 0.1 to 4 wt .-%, based on the total weight of the functionalized polyolefins, grafted on, which can also be done together with another monomer such as styrene.

The use of maleic acid-grafted polyolefins has become widely used in industrial applications, particularly for impact modifiers or as compatibilizers in blends and mechanically reinforced systems

(Polymer, 2001, 42, 3649-3655 and cited literature). This source also exemplifies the preparation of such functionalized polyolefins.

A typical representative of a functionalized polyolefin is the

polypropylene-based, acid-anhydride-grafted Admer QB 520 E (Mitsui Chemicals). In principle, it is also possible to use light-flowing maleic acid-grafted admixtures Polypropylene from Kometra (eg SCONA TPPP 8012).

Another functionalization option is the melt blend of unfunctionalized polyolefins with reactive compatibilizers containing epoxide or carboxylic acid anhydride moieties. Typical examples

Copolymers consisting of ethylene, one or more non-reactive

Lotader AX8900 (Arkema) represents a typical representative with glycidyl methacrylate units. The ratio of polyamide component to polyolefin component is between 9 to 1 and 2 to 3.

Even without further statements, it is assumed that a person skilled in the art can use the above description to the greatest extent. The preferred ones

Embodiments and examples are therefore to be considered as merely descriptive, in no way limiting, disclosure.

Hereinafter, the present invention will be explained in more detail by way of examples. Alternative embodiments of the present invention are obtainable in an analogous manner.

Examples

Unpretreated sheet metal plates of various metal alloys were pretreated by means of conversion. The following conversion agents were used:

A: Granodine 958 A from Henkel, Germany, containing, inter alia, phosphoric acid and zinc bis (dihydrogen phosphate),

B: Granodine 958 A from Henkel, Germany, additionally containing 170 ppm of Grano Toner 38 from Henkel, Germany (component comprising fluoride and hydrogendifluoride anions),

C: Granodine 1455 T from Henkel, Germany, containing, inter alia, phosphoric acid and dihydrogen hexafluorotitanate and

D: Alodine 4595 from Henkel, Germany, containing inter alia

Dihydrogenhexafluorozirconat.

As metal alloys were used:

- M1: HDG EA (sheet thickness 0.6mm) according to DIN EN10142

- M2: DX56D Z140 (sheet thickness 1, 0mm) according to DIN EN10346

- M3: DX51 D Z140 (sheet thickness 1, 0mm) according to DIN EN10346

- M4: AIMg3 EN AW-5754 H1 1 1 according to DIN EN 573-3

- M5: Steel ZSTE 800 according to DIN EN10142

After application of the conversion solution according to the manufacturer's instructions by immersion in the solutions and drying of the layers, the metal samples were coated with a primer composition. As composition were applied

I: a copolyamide-based hot melt adhesive containing an epoxy component and a blocked polyisocyanate as a powder coating,

II: Solvent-containing spray paint A containing 29% by weight of a copolyamide-based hot melt adhesive containing an epoxy component and a blocked polyisocyanate, and

- III: Solvent-containing spray paint B containing 30 wt .-% of a A copolyamide-based hot melt adhesive containing an epoxy component and a blocked polyisocyanate.

IV: hot melt adhesive based on copolyamide (Vestamelt Z2366-P1 from Evonik) containing an epoxy component and a blocked polyisocyanate and a functionalized polyolefin as a powder coating.

The four compositions I to IV contain the same hot melt adhesives.

The paint system was applied by spraying with a layer thickness of 50 to 70 μm and the powder coating was applied electrostatically with a layer thickness of 50 to 100 μm. The spray paint and powder coating were baked at 150 ° C for 5 minutes. The coated sheets were placed in a preheated autoclave (oven). After the baking process, the metal sheets were cut with shearing shears into metal strips measuring 24.9 mm x 59.8 mm which were suitable for the injection molding cavity

(Tolerance ± 0.2 mm) cut.

The metal strips were then inserted into a tempered injection mold for the production of the final hybrid components and overmoulded with a thermoplastic. The following molding compositions were used as the plastic component:

K1: PA6GF30 Durethan BKV30 H2.0 from LANXESS Deutschland GmbH

K2: PA610GF30 VESTAMID Terra HS1850 from Evonik Industries AG

K3: PA1010GF65 VESTAMID Terra BS1429 from Evonik Industries AG

K4: PA12GF30 VESTAMID L-GF30 from Evonik Industries AG.

K5: VESTAMID LX9012 from Evonik Industries AG

K6: PA6TGF50 VESTAMID HTplus M1035 from Evonik Industries AG

K7: PACM12 TROGAMID CX7323 from Evonik Industries AG

K8: PPLGF30 Celstran PP-GF30-05CN01 from TICONA K9: PA6.6 Durethan A30S from LANXESS Deutschland GmbH

K10 PBTGF30 VESTODUR GF30 from Evonik Industries AG

The plastics were processed on a type Allrounder 420

(Screw diameter 25 mm) at a melt temperature of 280 ° C, a

Tool temperature of 80 ° C or 120 ° C and at an injection rate of about 30 cc / s. For the PPAGF50 and PPLGF30, however, tool temperatures of 120 ° C and 70 ° C and melt temperatures of 335 ° C and 270 ° C were used.

It was important to provide an injection delay of approx. 30 s, so that the inserted metal strip could be preheated to the tool temperature, whereby the adhesion was positively favored. After demoulding, the individual tensile shear specimens were separated from the sprue.

The test specimens used had the following design features:

The specimens thus produced were stored at 50% relative humidity for at least 24 hours at 23 ° C to a uniform conditioning state

guarantee. The specimens are then clamped in a standard tensile testing machine Zwick / Roell Z-020 and tested at a speed of 5 mm / min at 23 ° C with a distance between the clamps and the overlap area of about 15 mm / side. Steel KV HV Plastic Temp. In ° C Overlap Adhesive strength in mm in MPa

M1 ^* Without ¹ K1 80 25x25 1, 2

M1 A ¹ K1 80 25x25 4.1

M1 B ¹ K1 80 25x25 7.2

M1 ^* Without ¹ K1 120 25x25 U

M1 A ¹ K1 120 25x25 6,7

M1 B ¹ K1 120 25x25 8.4

M1 A II K1 120 25x25 5.3

M1 B II K1 120 25x25 6.2

M2 C II K1 120 25x25 7.4

M1 A III K1 120 25x25 8.0

M1 B III K1 120 25x25 8,3

M2 C III K1 120 25x25 8,8

M1 A 1 K1 80 12.5x25 1 1, 2

M1 B 1 K1 80 12.5x25 13.1

M1 A II K1 80 12.5x25 13.9

M1 B II K1 80 12.5x25 14.9

M1 A 1 K9 80 12.5x25 5.8

M1 B 1 K9 80 12.5x25 6.5

M1 A 1 K3 80 12.5x25 1 1, 9

M1 B 1 K3 80 12.5x25 12.6

M1 A ¹¹ K3 80 12.5x25 13.5

M1 B ¹¹ K3 80 12.5x25 14.1

M4 A ¹¹ K3 80 12.5x25 1 1, 2

M4 B ¹¹ K3 80 12.5x25 12.5

M4 A ¹¹ K6 120 12.5x25 7.9

M4 B ¹¹ K6 120 12.5x25 10.2

M4 A 1 K10 80 12.5x25 2.2

M4 B 1 K10 80 12.5x25 4.5

M4 D 1 K10 80 12.5x25 3.9 M4 ^* Without II K1 80 12,5x25 2,3

M4 A II K1 80 12.5x25 7.7

M4 B II K1 80 12.5x25 13.7

M4 D II K1 80 25x25 7.5

M4 D III K1 80 25x25 7.2

M4 D II K1 120 25x25 8.2

M4 D III K1 120 25x25 7,8

M3 ^* B without K2 80 12.5x25 nm

M3 B 1 K2 80 12.5x25 1 1, 3

M3 B II K2 80 12.5x25 14.7

M4 ^* B without K2 80 12.5x25 nm

M4 B 1 K2 80 12.5x25 16.0

M4 B II K2 80 12.5x25 15.5

M3 ^* B without K3 80 12.5x25 nm

M3 B II K3 80 12.5x25 15.7

M4 ^* B without K3 80 12.5x25 nm

M4 B II K3 80 12.5x25 7.9

M3 ^* B without K1 80 12.5x25 nm

M3 B 1 K1 80 12.5x25 13.8

M3 B II K1 80 12.5x25 12.3

M4 ^* B without K1 80 12.5x25 nm

M4 B 1 K1 80 12.5x25 13.0

M4 B II K1 80 12.5x25 13.9

M4 ^* B without K5 80 ° C 25x25 nm

M4 B 1 K5 80 ° C 25x25 4,5

M3 ^* B without K6 120 ° C 12,5x25 1

M3 B II K6 120 ° C 12.5x25 1 1, 9

M3 ^* B without K7 80 ° C 25x25 nm

M3 B 1 K7 80 ° C 25x25 4.8

M3 B II K7 80 ° C 25x25 3.7

M4 ^* B without K8 70 ° C 12.5x25 nm

M4 B IV K8 70 ° C 12.5x25 5.8 M5 ^* B without K4 80 ° C 20x20 nm

M5 B 1 K4 80 ° C 20x20 8.8

M5 B II K4 80 ° C 20x20 10.6

^* not according to the invention

n. m. = not measurable (no liability)

KV: conversion agent; HV: adhesion promoter composition; Temp:

mold temperature

The results show that the coating of the conversion layer and the adhesion promoter layer can achieve an increased adhesion strength between metal and plastic in hybrid components compared to systems without a conversion layer. The adhesive strength is increased in particular with conversion agents used which halide-containing, preferably fluoride-containing, are (converters B and C).

Claims

claims

1 . A method of making a hybrid component comprising metal and plastic comprising the steps

a. Pretreatment of the metal surface by applying at least one

Conversion layer,

b. Applying at least one layer of a primer composition and

c. Bonding the metal to the plastic,

characterized in that the primer composition contains at least one copolyamide-based hot melt adhesive.

2. The method according to claim 1, characterized in that the copolyamide

at least one epoxy component and at least one blocked polyisocyanate are added as further constituents of the hot-melt adhesive.

3. The method according to any one of the preceding claims, characterized in that the plastic reinforced, preferably fiber-reinforced.

4. The method according to any one of the preceding claims, characterized in that a conversion agent is used to produce the conversion layer.

5. The method according to claim 4, characterized in that the

Conversion agent contains halides.

6. The method according to claim 4, characterized in that the

Conversion agent salt-like halides, complex halides or mixtures of these halides contains.

7. The method according to claim 5, characterized in that the

Conversion agent contains fluorides.

8. The method according to any one of the preceding claims, characterized in that the plastic on the coated metal by injection molding, pressing,

Laminating, injection molding or (co-) extruding is applied.

9. The method according to any one of claims 1 to 4, characterized in that the conversion layer is obtained by a method for treating a surface, wherein from a working gas, a plasma jet or from a

Fuel gas is generated a flame jet, with which the surface is coated, wherein at least one precursor material to the working gas and / or the

Plasma jet or the fuel gas and / or the flame jet is supplied and reacted in the plasma jet or flame jet, wherein at least one reaction product of at least one of the precursors on the surface and / or deposited on at least one disposed on the surface layer.

10. coating for hybrid components comprising metals and plastics,

comprising at least one conversion layer and at least one layer of a primer composition obtainable by a method according to one of the preceding claims.

1 1. Hybrid component comprising metal and plastic, wherein the metal with the

Plastic is connected at least by a coating according to claim 10.

12. Use of the coating according to claim 10 as adhesion promoter between metal and plastic of a hybrid component.

13. Metal substrate coated with at least one coating according to claim 10.