Metal-plastic hybrid materials having steel and / or zinc and / or their alloys as metal components

Abstract

The present invention relates to a method for preparing a metal-plastic hybrid material, said material comprising at least one substrate having at least one metal surface made at least in part from steel and / or zinc and / or alloys thereof, and at least one thermoplastic material applied onto said metal surface of the substrate, in particular by using an acidic aqueous composition. Furthermore, the present invention also relates to a metal-plastic hybrid material obtainable by this method, to a method for using the acidic aqueous composition for bonding substrates to plastics, to such a metal-plastic hybrid material, and to a method for using the metal-plastic hybrid material as a part in the automotive or construction industry.

Description

[Technical Field]

[0001] The present invention relates to a method for preparing a metal-plastic hybrid material, said material comprising at least one substrate having at least one metal surface made at least in part from steel and / or zinc and / or alloys thereof, and at least one thermoplastic material applied onto said metal surface of the substrate, in particular by using an acidic aqueous composition. Furthermore, the present invention also relates to a metal-plastic hybrid material obtainable by this method, to the use of a water-soluble polymer, preferably when present in an acidic aqueous composition, for bonding a substrate to a plastic, to such a metal-plastic hybrid material, and to the use of the metal-plastic hybrid material as a part in the automotive or construction industry. [Background technology]

[0002] Metal-plastic hybrid materials are one of the solutions proposed for reducing weight in components such as structural parts used in the automotive industry, or in other parts such as battery covers, powertrain elements, and control panels. To achieve these parts and components, plastic and metal can be joined in several ways, and researchers are developing bonding materials that ideally combine the properties of both materials. However, joining dissimilar materials such as metal and plastic is extremely difficult due to the different chemical properties of the two materials and the resulting dissimilarities, such as the shrinkage of plastics observed during molding, as with thermoplastics.

[0003] Traditionally, adhesives have been used to bond metals and thermoplastic materials. However, manufacturing such products using adhesives not only requires additional manufacturing steps, but also leads to a decrease in adhesive strength over time or a loss of bonding strength at high temperatures. Therefore, applying such methods to technical fields such as the automotive industry is not appropriate, regardless of the associated economic and ecological disadvantages, because considerable heat resistance is often required here for electrodeposition and painting processes.

[0004] However, bonding galvanized steel, such as hot-dip galvanized steel (HDG), to thermoplastic materials without the use of adhesives is extremely difficult. In contrast to aluminum materials, where controlled etching or anodizing methods have been used to directly inject plastics into the metal surface, such methods cannot be applied to materials made of or constructed from galvanized steel, such as HDG. Plasma technology is sometimes used for this purpose, but in this case, only a small portion of the metal surface is treated due to equipment and other constraints. Furthermore, such processes also suffer from undesirable limitations, as the surface is only activated for a few hours.

[0005] It is known to apply polymer-plastic films to galvanized steel sheets by lamination, especially in the form of polymer-metal laminates or sandwich materials or structures, in which the polymer plastic is sandwiched between two metal substrates. Examples of typical sandwich structures and laminates are disclosed, for example, in WO 2016 / 83083 A1 and WO 2017 / 125261 A1, as well as WO 2017 / 098060 A, WO 2017 / 098061 A1, US 2015 / 314563 A1, and US 2019 / 022797 A1. WO 2016 / 83083 A1 relates to a product comprising at least one first metal layer and at least one plastic layer bonded to each other over their entire area to form a metal / plastic composite, and a method for producing such a product, in which the visible surface of the metal layer of the metal / plastic composite has a coil coating. WO 2017 / 125261 A1 discloses a method for producing a composite material having at least two layers of metal material and at least one layer of polymer matrix material disposed between the two layers. WO 2017 / 098060 A1 and WO 2017 / 098061 A1 relate to a method for producing a product in which a metal support designed as a sheet metal or plate covered with at least one prepreg having a thermally crosslinkable duroplastic matrix with continuous fibers is formed into a product by deep drawing, stretch deep drawing, or roll profiling after the duroplastic matrix of the prepreg is pre-crosslinked by heating. US 2015 / 314563 A1 discloses a laminate core and a method for connecting sheet metal parts to form a laminate core, in which the sheet metal part is separated from a sheet metal strip having a layer of curable polymer adhesive, and the sheet metal parts are placed on top of each other with the adhesive-applied surfaces facing each other and bonded under pressure to form a laminate core.US 2019 / 022797 A1 relates to a method for producing a plastic-metal hybrid part made from the metal surface of a metal substrate provided with a corrosion protection layer, the metal substrate having a surface with undercuts applied by means of a filler material, which are at least partially filled with a thermoplastic part that engages with the undercuts to form the plastic-metal hybrid part.

[0006] Further sandwich structures such as those described above are disclosed in WO 2018 / 145981 A1 and WO 2015 / 181004 A1. WO 2018 / 145981 A1 discloses a composite material comprising two metal sheets connected by a thermoplastic polymer film and an adhesion promoter layer disposed between each sheet and the film. The aqueous adhesion promoter composition used to provide the layer comprises a polymer selected from maleic acid / polyacrylic acid copolymers and (modified) polyacrylic acid, and a phosphate component. WO 2015 / 181004 A1 discloses a method for producing a sandwich structure in which a metal surface is contacted with an aqueous conversion composition containing, inter alia, zinc cations, phosphate, and polyacrylic acid, and the resulting coated, dried metal surface is then contacted with a layer of an organic polymer and the desired sandwich structure is formed by compression under pressure and / or temperature.

[0007] To produce polymer-metal laminates and the aforementioned sandwich materials, it is generally necessary to use thermoplastic materials with relatively low melting temperatures, such as polyethylene (PE) or polyethylene terephthalate (PET). Therefore, conventional methods for producing the aforementioned products are limited by the required polymer properties and are generally not applicable to plastics and thermoplastic materials with high melting temperatures, such as pure polyamide 6, and for these reasons, they are not easy to process.

[0008] It is therefore necessary to provide a metal-plastic hybrid material and a method for preparing the same, which contains steel and / or zinc and / or alloys thereof as metal components and which has excellent permanent or at least long-lasting adhesive properties as far as the adhesion between metal and plastic is concerned, and which at the same time can be prepared without the need to use conventional adhesives, which material further allows the use of a wider range of thermoplastic polymer materials than conventional lamination processes for preparing metal-plastic hybrid materials, in particular allowing the use of thermoplastic materials with a melting temperature above 200°C, and which can further be prepared in a flexible, easy, ecologically and economically advantageous manner. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] WO 2016 / 83083 A1 [Patent Document 2] WO 2017 / 125261 A1 [Patent Document 3] WO 2017 / 098060 A1 [Patent Document 4] WO 2017 / 098061 A1 [Patent Document 5] US 2015 / 314563 A1 [Patent Document 6] US 2019 / 022797 A1 [Patent Document 7] WO 2018 / 145981 A1 [Patent Document 8] WO 2015 / 181004 A1 Summary of the Invention [Problem to be solved by the invention]

[0010] It is therefore an underlying object of the present invention to provide a metal-plastic hybrid material, and a method for preparing the same, which comprises steel and / or zinc and / or alloys thereof as metal components and which has excellent permanent or at least long-lasting adhesive properties as far as the adhesion between metal and plastic is concerned, and which at the same time can be prepared without the need to use conventional adhesives, which material further allows the use of a wider range of thermoplastic polymer materials than conventional lamination processes for preparing the metal-plastic hybrid material, in particular allowing the use of thermoplastic materials with a melting temperature above 200°C, and which can further be prepared in a flexible, easy, ecologically and economically advantageous manner. [Means for solving the problem]

[0011] This object has been solved by the subject matter of the present claims and the preferred embodiments thereof disclosed herein, ie the subject matter described herein.

[0012] A first subject of the present invention is a method for preparing a metal-plastic hybrid material, said material comprising a substrate having at least one metal surface and at least one thermoplastic material applied onto said metal surface of said substrate, said method comprising at least steps 1) and 3), and optionally step 2), namely 1) at least partially applying an aqueous acidic composition onto at least one metal surface of a substrate to at least partially form a film on said surface, and optionally drying or curing said film to form a dried or cured layer; the metal surface is made at least in part of at least one steel and / or zinc and / or at least one alloy thereof, the acidic aqueous composition contains, in addition to water, as at least one component a1), at least one water-soluble polymer having at least one functional group selected from acid groups, hydroxyl groups, amino groups and mixtures thereof; 2) optionally applying at least one thermoplastic polymer material TM1 in the form of a foil at least partially onto the film or dried or cured layer obtained after step 1); 3) injecting at least one thermoplastic polymer material TM2, present in a molten state and identical or different to the thermoplastic material TM1 optionally applied in step 2), at least partially onto the film, the dried layer or the cured layer obtained after step 1), or onto the foil optionally obtained after step 2), to form a metal-plastic hybrid material. Includes.

[0013] A further subject of the invention is a metal-plastic hybrid material obtainable by this method.

[0014] A further subject of the present invention is the use of a water-soluble polymer as defined herein as component a1) of the acidic aqueous composition, preferably when present in said acidic aqueous composition as defined in relation to step 1) of the method, for adhering a metal surface of a substrate, at least partially made of steel and / or zinc and / or at least one alloy thereof, to a thermoplastic material present on said surface in the form of a foil, such as a foil made at least partially of at least one thermoplastic polymer material TM1, or applied onto said surface by injection molding, such as a thermoplastic polymer material TM2.

[0015] A further subject of the present invention is such a metal-plastic hybrid material, namely a metal-plastic hybrid material comprising: a substrate having at least one metallic surface made at least in part from at least one steel and / or zinc and / or at least one alloy thereof; a film or dry layer or hardened layer applied at least partially onto said metal surface, said film or dry layer or hardened layer being obtainable from at least partially applying onto said metal surface an aqueous acidic composition as defined in relation to said step 1) of the method of the present invention; Optionally, at least one thermoplastic polymer material TM1, preferably in the form of a film or a foil that is applied at least partially onto the dried or cured layer, as defined in optional step 2) of the method of the present invention, and At least one thermoplastic polymer material TM2, in a form obtainable from injection molding, preferably as defined in step 3) of the method of the present invention, applied at least partially onto the film, or onto the dried or cured layer, or onto the foil, if present, wherein material TM2 is identical to or different from the thermoplastic polymer material TM1, optionally present, and preferably comprises at least one polyamide.

[0016] A further subject of the present invention is the use of said metal-plastic hybrid material or of a metal-plastic hybrid material obtainable by the method of the present invention as a component in the automotive or construction industry.

[0017] It has been found that the acidic aqueous composition used in the present invention can provide a conversion coating on the metal surface of a substrate, while at the same time providing good adhesion between the metal surface and the thermoplastic material TM1 or TM2 applied thereon due to the adhesion-promoting properties of the resulting conversion coating or layer. It has been found that sufficient adhesion would not be achieved without the application of the acidic aqueous composition. Furthermore, and particularly surprisingly, it has been found that the water-soluble polymer present in the acidic aqueous composition functions as an adhesion promoter in this regard. Since the strength of the adhesive bond between the metal surface and the thermoplastic material used has been found to significantly affect the lifespan of the metal-plastic hybrid material, achieving good adhesion is particularly important. Furthermore, it has been found that surfaces comprising metal steel and / or zinc and / or at least one alloy thereof, particularly surfaces made at least partially from galvanized steel, can be used with substrates of all kinds of different shapes, such as sheets, coils, and / or other shapes.

[0018] Furthermore, it has been particularly surprising to discover that the adhesion problems and challenges known in the prior art when combining two dissimilar materials, i.e., a thermoplastic polymer such as TM2 or TM1 on the one hand, and at least one alloy such as steel and / or zinc and / or galvanized steel, especially HDG, on the other, can be overcome by the inventive method for preparing a metal-plastic hybrid material, in particular by combining step 3), which allows the thermoplastic polymer TM2 to be directly injected onto the metal surface of a substrate or onto a foil-containing surface of a substrate, with the use of an acidic aqueous composition for chemical pretreatment of the metal surface, as exemplified in step 1) of the inventive method, prior to carrying out step 3). It has also been discovered that the method for preparing a metal-plastic hybrid material can be directly applied by injection molding according to step 3) of the inventive method, even when using thermoplastic polymers such as TM2 with relatively high melting temperatures, such as polyamides, especially polyamide 6. Direct injection molding of a thermoplastic material onto a metal surface according to step 3) offers many advantages, among them simplicity, robustness, and a wide range of applications. The flexibility of the method is achieved, for example, by the fact that step 1) of the method can be used in a coil line with a roll coater or by spraying with a job coater, which makes the method very flexible.

[0019] It has also been found that by applying the acidic aqueous composition used in the present invention, not only is excellent adhesion achieved but also very good corrosion prevention effects are obtained.

[0020] Even more surprisingly, it has been found that the method of the present invention allows the thermoplastic polymer TM2 to be thermoplastically injected directly onto a metal surface containing steel and / or zinc and / or at least one alloy thereof, e.g., a surface made from galvanized steel, despite the very short contact time between TM2 and the metal surface, and despite the significant temperature difference between the molten thermoplastic polymer material TM2, which may exceed 200° C., and the substrate temperature of the surface, which is usually room temperature, i.e., in the range of 18° C. to 25° C., but which may also be heated, if necessary, to, for example, 80° C. In particular, it has been found that the presence of functional groups of the water-soluble polymer in the acidic aqueous composition used allows for very rapid bonding, before the thermoplastic material has had time to cool once applied / injected.

[0021] Furthermore, it has been found that the use of an acidic aqueous composition for chemical pretreatment of a metal surface as exemplified in step 1) of the method of the present invention, prior to carrying out step 3), also provides strong adhesion to a thermoplastic material TM1 when applied as a foil to the treated metal surface. It has been found that the foil formed by applying TM1 can then further serve as an adhesive or interface layer onto which the thermoplastic material TM2 is injected in step 3) of the method when carried out, particularly if the foil formed from TM1 in step 2) is chemically compatible with the material TM2 applied in step 3). DETAILED DESCRIPTION OF THE INVENTION

[0022] In the sense of the present invention, the term "comprises", for example in connection with an acidic aqueous composition, preferably has the meaning of "consists of". For example, with respect to an acidic aqueous composition, in addition to all essential components present therein, it is also possible for one or more of the further optional components specified below to be included therein. All components may in each case be present in their preferred embodiments as specified below.

[0023] The percentages and amounts by weight (wt%) of any of the components shown below present in the acidic aqueous composition are in each case based on the total weight of the acidic aqueous composition and add up to 100 wt%.

[0024] Methods of the Invention A first subject of the present invention is a method for preparing a metal-plastic hybrid material, said material comprising a substrate having at least one metal surface and at least one thermoplastic material applied onto said metal surface of said substrate, said method comprising at least steps 1) and 3), and optionally step 2).

[0025] The method may comprise further steps in addition to steps 1) and 3) and optionally step 2), for example, a cleaning step of the metal surface may be carried out before step 1), for example with an acidic, alkaline or pH-neutral, preferably alkaline, cleaning composition, wherein in the case of an acidic cleaning composition, said composition is different from the acidic aqueous composition used in step 1).

[0026] More specifically, before step 1), the following optional steps may be performed: Step A-1): A step of cleaning the surface of the substrate, preferably with an alkali, and optionally rinsing it thereafter.

[0027] Preferably, the method does not include a step involving treatment with chromium ions, such as Cr(VI) ions and / or Cr(III) ions. The optional rinsing that is part of step A-1) is preferably carried out with deionized water or tap water. Preferably, the rinsing is carried out with deionized water.

[0028] Base material The metal surface of the substrate is at least partially made of at least one steel and / or zinc and / or at least one alloy thereof. Preferably, the entire metal surface is at least partially made of at least one steel and / or zinc and / or at least one alloy thereof. The term "alloy" refers to both steel alloys and zinc alloys. More preferably, such a substrate is a metal substrate made at least partially of at least one steel and / or zinc and / or at least one alloy thereof. Examples of steel include galvanized steel, such as hot-dip galvanized steel (HDG), and alloys of at least one steel with zinc and / or magnesium. An example of a zinc alloy is a zinc-magnesium alloy. Preferably, the metal surface does not contain aluminum and / or aluminum alloys in an amount that exceeds the amount of the at least one steel and / or zinc and / or at least one alloy thereof present therein.

[0029] All kinds of substrates of different shapes and geometries can be used, preferably the substrates are selected from sheets and coils, parts, in particular parts suitable for use in the automotive industry, and mixtures thereof.

[0030] Preferably, the metal-plastic hybrid material consists of a substrate having at least one metal surface made at least in part from steel and / or zinc and / or at least one alloy thereof, and at least one thermoplastic material applied onto said metal surface in step 3) and optionally in step 2). Particularly preferably, the metal-plastic hybrid material does not comprise a further substrate having at least one metal surface. In particular, the metal-plastic hybrid material does not exhibit a sandwich structure in which the applied at least one thermoplastic material is sandwiched between two metal surfaces.

[0031] Method step 1) In step 1), the aqueous acidic composition is at least partially applied onto at least one metal surface of a substrate to at least partially form a film on said surface. Drying or curing of the optional film may be carried out in step 1) to form a dried or cured layer. Such drying or curing is preferably carried out. Drying is preferably carried out at a temperature in the range of, for example, 15°C to 100°C, more preferably 18°C ​​to 95°C, and especially 20°C to 90°C.

[0032] Step 1) is preferably a contacting step in which the metal surface is contacted with an aqueous acidic composition. "Contacting" includes spraying, dip coating, or roll coating procedures. "Contacting" may also be submerging the surface in water or manually wiping or brushing.

[0033] The treatment time, i.e. the period during which the surface is in contact with the acidic aqueous composition used in step 1), is preferably in the range of 15 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, most preferably 45 seconds to 5 minutes, for example 1 minute to 3 minutes, in each case when parts, in particular parts suitable for use in the automotive industry, are used as substrates. If the substrate is a coil, the treatment time is preferably less than 1 minute, more preferably less than 30 seconds or less than 15 seconds, even more preferably less than 10 seconds, and even more preferably in the range of 1 second to 5 seconds.

[0034] The temperature of the acidic aqueous composition used in step 1) is preferably 5 to 50°C, more preferably 15 to 45°C, and most preferably 25 to 40°C.

[0035] By carrying out step 1), a conversion coating is preferably formed on the metal surface. Preferably, after drying or curing, preferably after drying, the conversion coating has a concentration of 1 to 90 mg / m2 as determined by XRF (X-ray fluorescence spectroscopy). 2 , more preferably 5 to 85 mg / m 2 , and even more preferably 10 to 80 mg / m 2 , and even more preferably 15 to 75 mg / m 2A coating layer is formed having a coating mass of phosphorus (in each case calculated as P2O5 if component a7) defined below is present in the acidic aqueous composition). Preferably, after drying or curing, preferably after drying, a coating mass of 0.5 to 10 mg / m2, determined by XRF (X-ray fluorescence spectroscopy), is formed. 2 , more preferably 1 to 8 mg / m 2 , and more preferably 1.5 to 7 mg / m 2 , and even more preferably 2 to 6 mg / m 2 A coating layer is formed having a coating mass of manganese (calculated as metal in each case if component a4) defined below is present in the acidic aqueous composition).

[0036] acidic aqueous composition The acidic aqueous composition comprises, in addition to water, at least one component a1) which is at least one water-soluble polymer having at least one functional group selected from acid groups, hydroxyl groups, amino groups, and mixtures thereof, all components present in the composition being different from one another.

[0037] Preferably, the acidic aqueous composition used in step 1) has a pH value in the range of 0.1 to <7.0, more preferably 0.5 to 6.5, even more preferably 0.7 to 6.0, even more preferably 0.9 to 5.5, even more preferably 1.0 to 5.0, even more preferably 1.2 to 4.5, even more preferably 1.5 to 4.0, even more preferably 1.7 to 3.5, and most preferably 1.8 to 3.0. Preferably, the pH value is measured at room temperature (23°C). The pH can be adjusted, if necessary, using phosphoric acid, aqueous ammonia, and / or sodium carbonate. Most preferably, the pH value is in the range of 2.0±0.5.

[0038] In the sense of the present invention, the term "aqueous" in relation to the acidic aqueous composition used in step 1) preferably means that the composition comprises at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, particularly preferably at least 80% by weight, and most preferably at least 90% by weight of water, based on the total content of organic and inorganic solvents, including water. Thus, the composition may contain at least one organic solvent in addition to water, but in an amount less than the amount of water present.

[0039] Preferably, the acidic aqueous composition used in step 1) contains at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, particularly preferably at least 80% by weight and most preferably at least 90% by weight of water, in each case based on its total weight.

[0040] The acidic aqueous composition can be used as a dip-coat bath. However, as outlined above in connection with step 1), it can also be applied by virtually any conventional coating procedure, such as spray coating, roll coating, brushing, wiping, etc. Spray or roll coating are preferred.

[0041] The acidic aqueous composition used in step 1) is preferably a solution.

[0042] Preferably, the acidic aqueous composition used in step 1) has a temperature in the range of 18 to 35°C, more preferably 20 to 35°C, especially 20 to 30°C.

[0043] Water-soluble polymer (component a1) The acidic aqueous composition comprises as at least one component a1) at least one water-soluble polymer having at least one functional group selected from acid groups, hydroxyl groups, amino groups and mixtures thereof.

[0044] The solubility is determined at a temperature of 20° C. and atmospheric pressure (1.013 bar).

[0045] Preferably, the at least one water-soluble polymer used as component a1) is present in the acidic aqueous composition in an amount ranging from 0.1 to 5.0 g / L, more preferably from 0.3 to 4.5 g / L, even more preferably from 0.5 to 4.0 g / L, even more preferably from 0.7 to 3.5 g / L, even more preferably from 0.9 to 3.0 g / L, even more preferably from 1.1 to 2.5 g / L, and most preferably from 1.3 to 2.0 g / L. Alternatively, the at least one water-soluble polymer used as component a1) is present in the acidic aqueous composition in an amount ranging from 0.1 to 15.0 g / L, more preferably from 0.3 to 12.0 g / L, even more preferably from 0.5 to 11.0 g / L, and even more preferably from 0.7 to 10.0 g / L.

[0046] Preferably, the at least one water-soluble film-forming polymer used as component a1) has at least one functional group selected from carboxylic acid groups, phosphonic acid groups, sulfonic acid groups, hydroxyl groups, amino groups, and mixtures thereof, more preferably selected from carboxylic acid groups, hydroxyl groups, amino groups, and mixtures thereof, even more preferably selected from carboxylic acid groups.

[0047] Preferably, the at least one water-soluble polymer used as component a1) is a homopolymer or copolymer obtainable from the polymerization of at least one ethylenically unsaturated monomer, at least some of which have at least one functional group selected from acid groups, hydroxyl groups, amino groups, and mixtures thereof, more preferably a homopolymer or copolymer obtainable from the polymerization of at least one vinyl and / or (meth)acrylic monomer, at least some of which have at least one functional group selected from acid groups, hydroxyl groups, amino groups, and mixtures thereof. In particular in the case of vinylphenol homopolymers and copolymers, these polymers can be modified by condensation reaction, in particular the Mannich reaction, with compounds having amino groups, such as ethanolamine and / or N-methylglucamine.

[0048] Examples of monomers containing acid groups include acrylic acid, methacrylic acid, and maleic acid. Examples of monomers containing hydroxyl groups include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, glycerol mono(meth)acrylate, N-(2-hydroxypropyl) (meth)acrylamide, allyl alcohol, hydroxystyrene, hydroxyalkyl vinyl ethers such as hydroxybutyl vinyl ether and vinylbenzyl alcohol, vinylphenol, and vinyl alcohol. Examples of additional non-functional monomers that can be used, particularly those that do not have acid groups, hydroxyl groups, or mixtures thereof, include ethylene, propylene, butylene, and aliphatic C1-C 30(Meth)acrylic acid esters of monoalcohols, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, lauryl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 3-propylheptyl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate, but particularly aliphatic C1-C 30 Non-functional vinyl monomers are preferred over non-functional (meth)acrylic esters of monoalcohols.

[0049] If polymer a1) is a homopolymer, it is preferably a poly(meth)acrylic acid. If polymer a1) is a copolymer and has at least acid groups as functional groups, it is preferably a (meth)acrylic copolymer, preferably comprising a polymer backbone and at least one side chain attached to said polymer backbone, and carrying acid groups, such as carboxylic acid groups.

[0050] The term "(meth)acrylic" means "acrylic" and / or "methacrylic". Similarly, "(meth)acrylate" means acrylate and / or methacrylate, and "(meth)acrylic" means acrylic and methacrylic. A "(meth)acrylic polymer" is formed at least in part from "acrylic monomers" and / or "methacrylic monomers", but may also contain non-acrylic and non-methacrylic monomer units if other ethylenically unsaturated monomers, such as vinyl monomers, are additionally used when polymer a1) is a copolymer. Preferably, the backbone of such a (meth)acrylic copolymer is formed from more than 50 mol %, even more preferably more than 75 mol % of (meth)acrylic monomers.

[0051] Preferably, the at least one water-soluble polymer used as component a1) is selected from: (meth)acrylic acid homopolymers, in particular acrylic acid homopolymers; copolymers of (meth)acrylic acid and at least one ethylenically unsaturated monomer other than (meth)acrylic acid, in particular copolymers of (meth)acrylic acid and maleic acid; Copolymers of maleic acid and at least one ethylenically unsaturated monomer other than maleic acid, in particular copolymers of maleic acid and ethylene and / or propylene and / or at least one alkyl vinyl ether, such as methyl vinyl ether; Copolymers of vinylphosphonic acid and at least one ethylenically unsaturated monomer other than vinylphosphonic acid, in particular copolymers of (meth)acrylic acid and vinylphosphonic acid, and copolymers of (meth)acrylic acid, vinylphosphonic acid and maleic acid; vinyl alcohol homopolymer, copolymers of vinyl alcohol and at least one ethylenically unsaturated monomer different from vinyl alcohol, such as vinyl acetate; vinylphenol homopolymer, a copolymer of vinylphenol and at least one ethylenically unsaturated monomer different from vinylphenol; a copolymer of vinyl mercaptoethanol and at least one ethylenically unsaturated monomer different from vinyl mercaptoethanol, and Homopolymers and copolymers of vinylphenols, and mixtures thereof, modified with at least one amine, preferably at least one primary amine, such as N-ethanolamine and / or N-methylglucamine, preferably via the Mannich base reaction based on the condensation of formaldehyde with a primary or secondary amine.

[0052] More preferably, the at least one water-soluble polymer used as component a1) is selected from (meth)acrylic acid homopolymers, in particular acrylic acid homopolymers, copolymers of (meth)acrylic acid and at least one ethylenically unsaturated monomer other than (meth)acrylic acid, in particular copolymers of (meth)acrylic acid and maleic acid, copolymers of maleic acid and at least one ethylenically unsaturated monomer other than maleic acid, in particular copolymers of maleic acid and at least one alkyl vinyl ether such as ethylene and / or propylene and / or methyl vinyl ether, vinyl alcohol homopolymers, copolymers of vinyl alcohol and at least one ethylenically unsaturated monomer other than vinyl alcohol, homopolymers and copolymers of vinylphenol modified with at least one amine, preferably at least one primary amine, such as N-ethanolamine and / or N-methylglucamine, and mixtures thereof. Particularly preferred polymers are N-methylglucamine-modified poly(vinylphenol), N-ethanolamine-modified poly(vinylphenol), poly(maleic acid-co-vinyl methyl ether), poly(maleic acid-co-acrylic acid), polyacrylic acid, poly(vinylphosphonic acid-co-acrylic acid), poly(acrylic acid-co-maleic acid-co-vinylphosphonic acid), poly(acrylic acid-co-vinylmercaptoethanol), poly(acrylic acid-co-maleic acid-co-vinylmercaptoethanol), and mixtures thereof.

[0053] Preferably, the at least one water-soluble polymer has a weight average molecular weight (M) in the range of 1000 to 350000 g / mol, preferably 2000 to 325000 g / mol, more preferably 3000 to 300000 g / mol, even more preferably 4000 to 375000 g / mol. W The weight average molecular weight is determined by the method described in the "Method" section below.

[0054] If a polymer a1) is used which is a poly(meth)acrylic acid, in particular a polyacrylic acid, it preferably has a weight average molecular weight (M) in the range of 10,000 to 350,000 g / mol, preferably 50,000 to 325,000 g / mol, more preferably 100,000 to 300,000 g / mol, even more preferably 150,000 or 200,000 to 375,000 g / mol. W If a polymer a1) is used which is a copolymer at least partially prepared from maleic acid, it preferably has a weight average molecular weight (M) in the range of 10,000 to 200,000 g / mol, preferably 15,000 to 150,000 g / mol, more preferably 20,000 to 100,000 g / mol, even more preferably 30,000 to 80,000 g / mol. W If a polymer a1) is used which is a homopolymer or copolymer at least partially prepared from vinyl alcohol and / or vinylphenol, it preferably has a weight average molecular weight (M) in the range of 500 to 100,000 g / mol, preferably 750 to 50,000 g / mol, more preferably 1,000 to 25,000 g / mol, even more preferably 1,000 to 10,000 g / mol. W )

[0055] Optional component a2) Preferably, the aqueous acidic composition used in step 1) further comprises as at least one component a2) zinc cations, in each case calculated as metal, preferably in an amount ranging from 0 to 8.0 g / L, more preferably from 0.1 to 8.0 g / L, even more preferably from 0.2 to 6.0 g / L, even more preferably from 0.3 to 5.0 g / L, and even more preferably from 0.5 to 3.0 g / L. Alternatively, at least component a2) is present in the acidic aqueous composition in an amount ranging from 0.1 to 50.0 g / L, more preferably from 0.3 to 45.0 g / L, even more preferably from 0.5 to 40.0 g / L, and even more preferably from 0.7 to 35.0 g / L.

[0056] The aqueous acidic composition may include additional components, as listed below. As used herein, the term "further comprising" in reference to the components of the aqueous composition means "in addition to the essential components." Thus, such "additional" components include ions other than the metal ions described above.

[0057] Preferably, (i) The aqueous acidic composition used in step 1) comprises at least one of components a3) and a4), preferably both a3) and a4), or only a4), i.e. as at least one component a3) at least one metal cation selected from the group of titanium ions, zirconium ions and hafnium ions, and mixtures thereof, preferably at least one metal cation selected from titanium ions and zirconium ions, and mixtures thereof, in an amount in the range of preferably 5 to 5000 ppm, more preferably 7.5 to 4000 ppm, even more preferably 10 to 3000 ppm, even more preferably 12.5 to 2000 ppm, even more preferably 15 to 1000 ppm, particularly preferably 17.5 to 500 ppm, even particularly preferably 20 to 300 ppm and most preferably 30 to 200 ppm, in each case calculated as metal, and / or as at least one component a4) manganese cations, preferably in an amount ranging from 0 to 5.0 g / L or from 0.1 to 5.0 g / L, more preferably from 0.1 to 4.0 g / L, even more preferably from 0.2 to 3.5 g / L, even more preferably from 0.3 to 3.0 g / L, even more preferably from 0.5 to 2.5 g / L, in each case calculated as the metal, or preferably in an amount ranging from 0 to 30.0 g / L or from 0.1 to 27.5 g / L, more preferably from 0.1 to 25.0 g / L, even more preferably from 0.2 to 22.5 g / L, in each case calculated as the metal, Including, Optionally, at least one optional component a5) is a free fluoride anion; and / or As optional component a6), at least one organosilane, preferably in an amount ranging from 10 to 200 ppm or or (ii) The aqueous acidic composition used in step 1) preferably comprises in combination with a2) at least component a7), i.e. As at least one component a7), phosphate anions preferably in an amount ranging from 1 to 150 g / L, more preferably from 2 to 125 g / L, even more preferably from 3.0 to 100 g / L, even more preferably from 4.0 to 95 g / L, even more preferably from 5.0 or from 7.5 to 90 g / L, in each case calculated as P2O5, or preferably in an amount ranging from 1 to 200 g / L, more preferably from 2.0 to 195 g / L, even more preferably from 3.0 to 190 g / L, even more preferably from 4.0 to 185 g / L, even more preferably from 5.0 or from 7.5 to 180 g / L, in each case calculated as P2O5. and optionally as at least one component a4), manganese cations preferably in an amount ranging from 0 to 5.0 g / L or 0.1 to 5.0 g / L, more preferably 0.1 to 4.0 g / L, even more preferably 0.2 to 3.5 g / L, even more preferably 0.3 to 3.0 g / L, even more preferably 0.5 g / L to 2.5 g / L, in each case calculated as the metal, or preferably in an amount ranging from 0 to 30.0 g / L or 0.1 to 27.5 g / L, more preferably 0.1 to 25.0 g / L, even more preferably 0.2 to 22.5 g / L, in each case calculated as the metal; further comprising wherein in case (i) the phosphate anion a7) is preferably absent, In case (ii), the acidic aqueous composition is preferably free or essentially free of free fluoride anions a5).

[0058] Most preferred are aqueous acidic compositions according to option (ii), further comprising at least one component a2) (zinc cation).

[0059] In the case of option (i), the aqueous acidic composition used in step 1) preferably comprises at least one component a3), which is preferably selected from titanium ions and zirconium ions and mixtures thereof, most preferably titanium ions. The content of component a3) can be monitored and determined by means of ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy). This method is described in detail below. Preferably, a precursor metal compound is used to generate the metal cation present in the composition as component a3). Preferably, the precursor metal compound is water-soluble. The solubility is determined at a temperature of 20°C and atmospheric pressure (1.013 bar). Particularly preferred zirconium, titanium and / or hafnium compounds are complex fluorides of these metals. The term "complex fluoride" includes singly and multiply protonated forms, as well as deprotonated forms. It is also possible to use mixtures of such complex fluorides. Complex fluorides in the sense of the present invention are complexes of zirconium, titanium and / or hafnium formed with fluoride ions in the composition, for example, by coordination of fluoride anions to zirconium, titanium and / or hafnium cations in the presence of water. Furthermore, carbonates and / or complex carbonates and / or lactates and / or, in particular, nitrates of zirconium, titanium and / or hafnium can also be used. However, the cations are preferably incorporated into the composition in the form of their complex fluorides.

[0060] In the case of option (i), the aqueous acidic composition used in step 1) preferably comprises manganese cations as a4). In this case, manganese as metal can be added, for example, to phosphoric acid, and a dilution thereof containing manganese cations a4) (and phosphate anions a7)) can be included in the composition. In the case of option (ii), manganese cations a4) can also be present.

[0061] In the case of option (i), the aqueous acidic composition used in step 1) optionally, but preferably, contains at least one free fluoride anion of component a5). This arises from the presence of component a3), i.e., in particular when complex fluorides of Ti, Zr, and / or Hf are present in the composition, but may also or alternatively arise from the presence of any other component, as described below, such as the incorporation of at least one water-soluble fluorine compound. Examples of such water-soluble fluorine compounds are fluorides (other than complex fluorides of Ti, Zr, and / or Hf) and hydrofluoric acid. The free fluoride content is determined using a fluoride ion-sensitive electrode according to the method disclosed in the "Method" section.

[0062] Optionally, in the case of option (i), the acidic aqueous composition used in step 1) further comprises at least one organosilane as optional component a6), examples of which include, for example, (3-aminopropyl)trimethoxysilane, (3-aminopropyl)triethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, (3-mercaptopropyl)triethoxysilane, (3-glycidyloxypropyl)trimethoxysilane and / or (3-glycidyloxypropyl)triethoxysilane, and / or vinyltrimethoxysilane.

[0063] In the case of option (ii), the aqueous acidic composition used in step 1) preferably comprises at least a component a7), i.e., a phosphate anion as at least one component a7), in combination with a2).By using a phosphate anion, an amorphous zinc phosphate layer is formed on the metal surface.The phosphate anion is preferably added in the form of phosphoric acid.

[0064] Other optional components Optionally, the aqueous acidic composition further comprises at least one metal cation selected from the group consisting of cations of metals from the first to third subgroups of the Periodic Table of the Elements (copper, zinc, and scandium groups), the fifth to eighth subgroups (vanadium, chromium, iron, cobalt, and nickel groups), including the lanthanides, and the second main group of the Periodic Table of the Elements (alkaline earth metals), lithium, bismuth, and tin. However, preferably, metal cations from the chromium, cobalt, and nickel groups are not used. The metal cations are generally introduced in the form of their water-soluble compounds, preferably as their water-soluble salts. Preferred cation(s) are selected from the group consisting of cations of cerium and other lanthanides, iron, calcium, copper, magnesium, niobium, tantalum, yttrium, vanadium, lithium, bismuth, and tin.

[0065] Optionally, the aqueous acidic composition further comprises at least one pH-adjusting substance, preferably selected from the group consisting of nitric acid, sulfuric acid, methanesulfonic acid, acetic acid, aqueous ammonia, sodium hydroxide and sodium carbonate, where nitric acid, aqueous ammonia and sodium carbonate are preferred. Depending on the pH value of the acidic aqueous composition, the compounds may be in a fully or partially deprotonated form, or in a protonated form.

[0066] Optionally, the aqueous acidic composition further comprises at least one complexing agent, an example of which is 1-hydroxyethane-1,1-diphosphonic acid (HEDP).

[0067] Optionally, the aqueous acidic composition further comprises at least one corrosion inhibitor. Examples include L-cysteine ​​and other amino acids, benzotriazole, and mixtures thereof. Preferably, the at least one corrosion inhibitor does not contain any type of metal ion.

[0068] Optionally, particularly when the aqueous composition is alkaline, the aqueous composition further comprises at least one organic acid, preferably at least one organic acid having at least two carboxylic acid groups and / or at least one organic acid having at least one carboxylic acid group and at least one additional functional group having at least one donor atom, such as an OH group, such as lactic acid. The presence of such a compound may help stabilize at least one metal ion in the composition, such as Zr cation.

[0069] The aqueous composition may further comprise at least one of the following components: one or more waxes, one or more wetting agents, and one or more defoaming agents.

[0070] Optional step 1a) After step 1), the surface of the substrate obtained after contacting in step 1) can be optionally rinsed, preferably with deionized water or tap water (optional step 1a)). If this step is performed, it is preferably performed before the drying or curing performed in step 1).

[0071] Optional step 2) of the method, and step 3) of the method In optional step 2), at least one thermoplastic polymer material TM1 is applied in the form of a foil, at least partially, onto the film or dried or cured layer obtained after step 1) (or after optional step 1a)).

[0072] Preferably, the formed foil obtained using the thermoplastic polymer material TM1 in optional step 2) serves as a compatibilizer material for the thermoplastic polymer material TM2 optionally subsequently injected in step 3). Preferably, optional step 2) is not performed by injection molding. Preferably, a foil made from at least one thermoplastic polymer material TM1 is applied at least partially onto the film or dried or cured layer obtained after step 1) (or after optional step 1a)).

[0073] Preferably, optional step 2) is not performed. If optional step 2) is performed, thermoplastic polymer material TM1 is preferably different from thermoplastic polymer material TM2.

[0074] In step 3), at least one thermoplastic polymer material TM2, which is identical to or different from the thermoplastic material TM1 optionally applied in step 2) and which is present in a molten state, is applied at least partially onto the film obtained after step 1) or onto the dried or cured layer, or onto the foil optionally obtained after step 2), to form a metal-plastic hybrid material.

[0075] Step 3) is an injection molding step in which the thermoplastic polymer material TM2 is preferably injected directly onto the metal surface of the substrate to which the acidic aqueous composition has previously been applied in step 1).

[0076] Optional step 2) and / or step 3) can be carried out continuously or discontinuously.

[0077] The substrate obtained after step 1) or after optional step 1a) is preferably heated before optional step 2) or before carrying out step 3), preferably to a temperature above the melting temperature of the respective thermoplastic material used.

[0078] Preferably, the thermoplastic polymer material TM1 used in optional step 2) and / or the thermoplastic polymer material TM2 used in step 3) are applied in such a way that a vacuum is applied to bring the respective thermoplastic polymer material into contact with at least a portion, preferably the entire surface, of the substrate whose surface was in contact with the acidic aqueous composition in step 1), and to remove any air trapped between the surface of the substrate and the respective thermoplastic polymer material. Preferably, the temperature of the substrate and the respective thermoplastic polymer material applied thereto is maintained above a temperature that promotes bonding between the applied thermoplastic polymer material and the metal substrate. After the aforementioned heating, the substrate is preferably placed in an apparatus capable of applying the respective thermoplastic polymer material to the surface of the substrate, preferably a thermoforming apparatus capable of applying the thermoplastic polymer material TM1 as a foil. Alternatively, the substrate can first be placed in an apparatus in which the respective thermoplastic polymer material is applied, and then the substrate can be heated before the respective thermoplastic polymer material is placed thereon. Preferably, after the heated substrate is placed in the apparatus, or after the substrate is placed in the apparatus and then heated, the respective thermoplastic polymer material is placed on the substrate and optionally heated, e.g., in the case of step 3), the material is injected in a molten state. If the respective thermoplastic polymer material is heated, the heating can be effected, for example, by infrared radiation.

[0079] The temperature to which each thermoplastic polymer material is heated is preferably selected so that the thermoplastic material has rubber elasticity. To this end, the thermoplastic material is preferably heated to a temperature above the glass transition temperature of the thermoplastic material if the thermoplastic material is an amorphous thermoplastic material, or above the melting point of the crystal if the thermoplastic material is a semi-crystalline thermoplastic material, but preferably below the melting point to avoid damage. After placing each thermoplastic polymer material on the substrate surface, and optionally after heating the material, a vacuum is preferably applied as described above. By applying a vacuum, each thermoplastic polymer material preferably adheres to the surface of the substrate and achieves a strong connection. Removing air that may be trapped between the surface of the substrate and each thermoplastic polymer material preferably results in a smooth surface without blistering. To apply the vacuum, the substrate may have an opening through which air can be removed. If the substrate does not have an opening, air between the substrate and each thermoplastic polymer material can also be removed at the edges of the thermoplastic polymer material. When removing air at the edges, it is preferable to remove air from at least two opposing sides, preferably around the entire periphery of each thermoplastic polymer material. A suitable vacuum pump can be used to apply the vacuum. When removing air at the edge of each thermoplastic polymer material, each thermoplastic polymer material is preferably fixed in a device for applying a vacuum so that a gap is formed between the substrate and the edge of each thermoplastic polymer material and the vacuum is applied through the gap. By applying the vacuum, each thermoplastic polymer material preferably contacts the substrate uniformly over its entire surface, resulting in the formation of a uniform layer on the surface of the substrate.

[0080] After the respective thermoplastic polymer materials are preferably brought into contact with the entire surface of the substrate, the temperatures of the substrate and the respective thermoplastic polymer materials are maintained at a temperature that promotes bonding between the thermoplastic materials and the substrate, preferably above the melting point of the thermoplastic materials. By maintaining the temperature, the thermoplastic materials preferably chemically react with the functional groups of the water-soluble polymer originally present in the acidic aqueous composition, thereby achieving stable bonding between the surface of the substrate and the respective thermoplastic polymer materials, and forming a composite member including a "metal layer" (the metal surface of the substrate) and a "polymer layer" (the applied thermoplastic material).

[0081] Preferably, at least before step 3) is carried out, the substrate obtained after step 1), optionally 1a) or optionally step 2) is placed in a mold before step 3) is carried out.

[0082] Thermoplastic polymer materials TM1 and TM2 Thermoplastic polymer material TM2 may be the same as or different from thermoplastic polymer material TM1, and is preferably different.

[0083] Preferably, each of the thermoplastic polymer materials TM1 and TM2 is capable of chemically bonding with the functional groups of the water-soluble polymer originally present in the acidic aqueous composition used in step 1).

[0084] Preferably, the thermoplastic polymer material TM2 is selected from polyamide, polyester such as PET and / or PBT, polyurethane, polycarbonate, polyolefin such as polypropylene and polyethylene, and mixtures thereof. It is also possible to use recycled thermoplastic polymer materials such as recycled polyamide. Most preferred is polyamide. Preferably, the polyamide is selected from PA6, PA66, PA66 / 6, PA6.10, PA6.12, PA12, PA9T, PA6I / 6T, PA6T / 6I, PA6 / 6.36, and combinations thereof. Preferably, at least one polyamide is applied as the at least one thermoplastic polymer material TM2 via step 3).

[0085] The thermoplastic polymer materials TM1 and / or TM2, preferably TM2, such as polyamides, can be used in compounded form with at least one additive, such as at least one rubber, such as EPDM (ethylene propylene diene monomer) rubber, to improve the properties of the thermoplastic polymer material, in particular to reduce its water uptake. Alternatively or additionally, the thermoplastic polymer materials TM1 and / or TM2, preferably TM2, can (i) optionally comprise at least one fiber, such as glass fiber, carbon fiber, aramid fiber, and combinations thereof, and / or (ii) optionally comprise a polyether block polyamide, such as a polyether diamine and an aliphatic C4-C 40 Dicarboxylic acids and / or C6-C 12 Copolymerizates with lactams, such as caprolactam or lauryllactam, aliphatic C4-C 10 Diamines and Aliphatic C4-C 40 Copolymerizates with dicarboxylic acids, C6-C 12 and / or (iii) optionally, at least one impact modifier, such as maleic anhydride graft copolymers of ethylene with at least one of an α-olefin, a (meth)acrylic acid ester, and (meth)acrylic acid, copolymers of maleic anhydride with ethylene and at least one of a (meth)acrylic acid ester, styrene maleic anhydride, or maleic anhydride graft polypropylene.

[0086] Preferably, the thermoplastic polymer material TM1 is selected from polyamides, polyesters such as PET and / or PBT, polyurethanes, polycarbonates, polyolefins such as polypropylene and polyethylene, and mixtures thereof. It is also possible to use recycled thermoplastic polymer materials, such as recycled polyamides. Preferably, the polyamides are selected from PA6, PA66, PA66 / 6, PA6.10, PA6.12, PA12, PA9T, PA6I / 6T, PA6T / 6I, PA6 / 6.36, and combinations thereof. Most preferred are polyolefins. Preferably, at least one polyolefin is applied as the at least one thermoplastic polymer material TM1 via optional step 2).

[0087] Preferably, the thermoplastic polymer material TM1 has a melting point in the range of 80° C. to 280° C. For example, polyolefins may have a melting point of 80° C., while polyamides have significantly higher melting points, for example 280° C.

[0088] Preferably, the thermoplastic polymer material TM2 has a melting point in the range defined for the thermoplastic polymer material TM1.

[0089] Metal-plastic hybrid materials obtainable by the method of the present invention A further subject of the invention is a metal-plastic hybrid material obtainable by the method according to the invention.

[0090] All preferred embodiments mentioned herein above in relation to the method of the invention and its preferred embodiments are also preferred embodiments of the metal-plastic hybrid material of the invention obtainable by said method.

[0091] Preferably, the metal-plastic hybrid material does not have a sandwich structure in which the metal surface of the substrate, preferably such substrate, is sandwiched between two thermoplastic materials. Preferably, therefore, the method of the present invention does not include the step of applying a thermoplastic polymer material, especially not in the form of a foil, to the metal surface of the substrate opposite to the metal surface to which the thermoplastic polymer material TM2 has been applied in step 3). Preferably, the dry layer thickness of the layer obtained from drying or curing the film obtainable from applying the aqueous acidic composition, as defined in relation to step 1) of the method of the present invention at least partially onto the metal surface, is in the range of 100 to 1000 nm, more preferably 150 to 750 nm, in particular 250 to 550 nm.

[0092] Methods of using water-soluble polymers and acidic aqueous compositions A further subject of the present invention is the use of a water-soluble polymer as defined hereinbefore as component a1) of an acidic aqueous composition, preferably when present in said acidic aqueous composition, as defined in connection with step 1) of the method of the present invention, for adhering a metal surface of a substrate, at least in part made of steel and / or zinc and / or at least one alloy thereof, to a thermoplastic polymer material present on said surface in the form of a foil or applied thereto by injection molding, preferably by utilizing the method of the present invention.

[0093] All preferred embodiments described herein above in relation to the inventive method, the inventive metal-plastic hybrid material obtainable by said method, and preferred embodiments thereof, are also preferred embodiments of the inventive method of use.

[0094] Metal-plastic hybrid materials A further subject of the present invention is such a metal-plastic hybrid material, namely a substrate having at least one metallic surface made at least in part from at least one steel and / or zinc and / or at least one alloy thereof; a film or dried layer or cured layer at least partially applied onto the metal surface, which film or dried layer or cured layer is obtainable from at least partially applying onto the metal surface an aqueous acidic composition as defined in relation to said step 1) of the method of the present invention; Optionally, at least one thermoplastic polymer material TM1 in the form of a film or foil that is applied at least partially onto the dried or cured layer, as defined in optional step 2) of the method of the present invention, and Preferably, at least one thermoplastic polymer material TM2 in the form obtained from injection molding, which is applied at least partially onto the film or the dried or cured layer, or onto the foil, if present, as defined in step 3) of the method of the present invention, and which is identical to or different from the thermoplastic polymer material TM1. A metal-plastic hybrid material comprising:

[0095] Preferably, a metal-plastic hybrid material is obtainable by the method of the present invention. Preferably, the metal-plastic hybrid material is a laminate.

[0096] Preferably, the thermoplastic polymer material TM2 present in a form obtainable from injection molding has a total thickness in the range of 200 to 800 μm.

[0097] All preferred embodiments described herein above in relation to the inventive method, the inventive metal-plastic hybrid material obtainable by said method, the inventive use method and their preferred embodiments are also preferred embodiments of such inventive metal-plastic hybrid material.

[0098] Preferably, the film or dry or cured layer, preferably the dry layer, applied at least partially onto the metal surface of the metal-plastic hybrid material contains, if present in the acidic aqueous composition, a component a7) as defined below, in an amount of 1 to 90 mg / m, calculated as P2O5 in each case. 2 , more preferably 5 to 85 mg / m 2 , and even more preferably 10 to 80 mg / m 2 , and even more preferably 15 to 75 mg / m 2 Preferably, the layer formed after drying or curing, preferably after drying, has a coating mass determined by XRF (X-ray fluorescence spectroscopy) of 0.0.5 to 10 mg / m2 of phosphorus, calculated as metal in each case, if component a4) as defined below is present in the acidic aqueous composition. 2 , more preferably 1 to 8 mg / m 2 , and even more preferably 1.5 to 7 mg / m 2 , and even more preferably 2 to 6 mg / m 2 of manganese, with a coating mass determined by XRF (X-ray fluorescence spectroscopy).

[0099] How to use metal-plastic hybrid materials A further subject of the present invention is the use of said metal-plastic hybrid material or of a metal-plastic hybrid material obtainable by the method of the present invention as a component in the automotive or construction industry.

[0100] In this specification, all preferred embodiments described above in connection with the inventive method, the inventive metal-plastic hybrid material obtainable by said method, the inventive use method as described above, such inventive metal-plastic hybrid material, and their preferred embodiments, are also preferred embodiments of the inventive use method of the metal-plastic hybrid material.

[0101] In particular, metal-plastic hybrid materials can be used in the manufacture of automotive parts, especially those that require reduced weight. Further possible applications include the manufacture of battery housings and covers, and automotive panel controls.

[0102] method 1. Tensile adhesive strength The tensile bond strength was measured by a peel test according to ISO 4624:2016. A T-joint structure was used for the peel test.

[0103] 2.Average molecular weight M W and M n Decision Number average molecular weight and mass average molecular weight (M n and M W ) are measured according to the following protocol, respectively: Samples are analyzed by SEC (size exclusion chromatography) equipped with a MALS detector. Absolute molar masses are measured by setting the dn / dC value to 0.1875 mL / g, to ensure a recovery of approximately 90%. The polymer sample is dissolved in the mobile phase, and the resulting solution is filtered through a 0.45 μm Millipore filter. The elution conditions are as follows: Mobile phase: 100% by volume of H2O, 0.1 M NaCl, 25 mM NaH2PO4, 25 mM Na2HPO4; 100 ppm NaN3; Flow rate: 1 mL / min; Column: Varian Aquagel OH mixed H, 8 μm, 3*30 cm; Detection: RI (concentration detector Agilent) + MALLS (multi-angle laser light scattering) Mini Dawn Tristar + UV at 290 nm; Sample concentration: approximately 0.5% by weight in the mobile phase; Injection loop: 100 μL. The obtained M n and M W From the value of , the polydispersity P can be calculated.

[0104] 3. Determination of free fluoride content Free fluoride content is determined using a fluoride ion-selective electrode. The electrode is calibrated using at least three master solutions with known fluoride concentrations. The calibration process generates a calibration curve. This curve is then used to determine the fluoride content.

[0105] 4. ICP-OES The amount of a specific element, such as zirconium, titanium, or hafnium, in a sample under analysis is determined using inductively coupled plasma optical emission spectroscopy (ICP-OES) in accordance with DIN EN ISO 11885 (dated September 1, 2009). The sample is thermally excited in an argon plasma generated by a radio-frequency magnetic field, and the light emitted by electronic transitions is visualized as spectral lines of the corresponding wavelengths and analyzed using an optical system. There is a linear relationship between the intensity of the emitted light and the concentration of the element in question. Prior to implementation, calibration measurements are performed using known element standards (reference standards) as a function of the specific sample under analysis. These calibrations can be used to determine the concentration of unknown solutions, such as titanium, zirconium, or hafnium. [Example]

[0106] The following examples further illustrate the present invention but are not to be construed as limiting its scope.

[0107] 1. Preparation of Acidic Aqueous Coating Composition 1.1 Acidic aqueous compositions A1 to A5 (invention) and composition A6 (comparison) were prepared (1 L each). All compositions were chromium-free. Each of compositions A1 to A5 contained one of the following water-soluble polymers P1 to P5: P1: M over 150,000 g / mol W a commercially available polyacrylic acid having P2: A blend of P1 with a copolymer of maleic and acrylic acid. P3: N-ethanolamine modified polyvinylphenol, P4: Copolymer of maleic acid and ethylene, and P5: Copolymer of maleic acid and vinyl methyl ether.

[0108] [Table 1]

[0109] 1.2 Acidic aqueous compositions B1 to B7 (invention) and composition B8 (comparison) were prepared (1 L each). All compositions were chromium-free. Each of compositions B1 to B7 contained one of the water-soluble polymers P1, P2, P4, or P5 described above.

[0110] [Table 2]

[0111] 2. Pretreatment A hot-dip galvanized steel substrate (substrate T1, Gardobond® panel MBZ automotive quality) was used in the form of a metal sheet.

[0112] The substrates were cleaned using the commercially available alkaline product Gardoclean® S 5160 (60-70°C), followed by rinsing with tap water and then deionized water (30 seconds each).

[0113] A contacting step was then carried out to form a conversion coating layer having adhesion-promoting properties on the surface of the substrate, i.e., the surface of the substrate was contacted with one of the acidic aqueous compositions A1 to A6 or B1 to B8 described above in item 1. The contacting step was carried out in each case for 60 seconds by spraying one of the acidic aqueous compositions onto the surface of the substrate. The acidic aqueous composition was either heated to 25°C before spraying or applied with a roll coater.

[0114] After the contacting step, air was blown onto the surface, followed by a drying step (15 minutes at 60 to 70° C.) The thickness of the resulting dried layer was in the range of 50 to 200 nm.

[0115] 3. Preparation of Metal-plastic Hybrid Materials To reduce the water absorption of polyamide, polyamide 6 (PA6; commercially available product Ultramid® B27) as a thermoplastic polymer material was compounded with rubber materials and various standard additives to produce Ultramid® B3Z8. Before use, the polyamide was placed in an oven before application to obtain a "dry" polyamide. The compounded PA6 was then applied by injection molding directly to the preheated surface of the substrate obtained after pretreatment as described in section 2. The laminates produced by injection molding had thicknesses (of the plastic layer) ranging from 200 to 800 μm.

[0116] 4. Properties of the obtained metal-plastic hybrid material A number of properties of the product obtained by the method described in item 3 of this specification were investigated. These properties were determined according to the test methods previously described in this specification. The results are shown in Tables 2a-2b. In particular, the adhesive strength was investigated.

[0117] [Table 3]

[0118] Thermoplastics were injected over specific surface areas and the adhesive strengths of different compositions were compared. Surprisingly, minimal strength was achieved in peel tests.

[0119] When no polymer was present in the aqueous acidic compositions used (i.e., when compositions A6 and B8 were used), it was found that there was no adhesion between the plastic layer and the steel substrate, i.e., insufficient adhesive strength.

Claims

1. A method for preparing a metal-plastic hybrid material, said material comprising a substrate having at least one metal surface and at least one thermoplastic material applied onto said metal surface of said substrate, said method comprising at least steps 1) and 3), and optionally step 2), i.e. 1) at least partially applying an aqueous acidic composition onto at least one metal surface of a substrate to at least partially form a film on said surface, and optionally drying or curing said film to form a dried or cured layer; the metal surface is at least partially made of at least one steel and / or zinc and / or at least one alloy thereof, the acidic aqueous composition comprises, in addition to water, as at least one component a1), at least one water-soluble polymer having at least one functional group selected from acid groups, hydroxyl groups, amino groups and mixtures thereof; 2) optionally applying at least one thermoplastic polymer material TM1 in the form of a foil at least partially onto said film or dried or cured layer obtained after step 1); 3) Injecting at least one thermoplastic polymer material TM2, present in a molten state and identical or different to the thermoplastic material TM1 optionally applied in step 2), at least partially onto the film, dried layer or cured layer obtained after step 1) or onto the foil optionally obtained after step 2), to form a metal-plastic hybrid material. A method comprising:

2. 2. The method of claim 1, wherein the acidic aqueous composition used in step 1) has a pH value in the range of 0.1 to <7.0, preferably 0.5 to 6.5, more preferably 0.7 to 6.0, even more preferably 0.9 to 5.5, even more preferably 1.0 to 5.0, even more preferably 1.2 to 4.5, even more preferably 1.5 to 4.0, even more preferably 1.7 to 3.5, and most preferably 1.8 to 3.

0.

3. 3. The method according to claim 1 or 2, wherein the at least one water-soluble polymer used as component a1) is present in the acidic aqueous composition in an amount in the range of 0.1 to 5.0 g / L, preferably 0.3 to 4.5 g / L, more preferably 0.5 to 4.0 g / L, even more preferably 0.7 to 3.5 g / L, even more preferably 0.9 to 3.0 g / L, even more preferably 1.1 to 2.5 g / L, and most preferably 1.3 to 2.0 g / L.

4. 3. The method according to claim 1 or 2, wherein the at least one water-soluble polymer used as component a1) has at least one functional group selected from carboxylic acid groups, phosphonic acid groups, sulfonic acid groups, hydroxyl groups, amino groups, and mixtures thereof, more preferably selected from carboxylic acid groups, hydroxyl groups, amino groups, and mixtures thereof, even more preferably selected from carboxylic acid groups.

5. 10. The method according to claim 1, wherein the at least one water-soluble polymer used as component a1) is a homopolymer or copolymer obtainable from the polymerization of at least one ethylenically unsaturated monomer, preferably a homopolymer or copolymer obtainable from the polymerization of at least one vinyl and / or (meth)acrylic monomer, at least some of which monomers carry at least one functional group according to claim 4.

6. The at least one water-soluble polymer used as component a1) is preferably a (meth)acrylic acid homopolymer, in particular an acrylic acid homopolymer, a copolymer of (meth)acrylic acid and at least one ethylenically unsaturated monomer other than (meth)acrylic acid, in particular a copolymer of (meth)acrylic acid and maleic acid, a copolymer of maleic acid and at least one ethylenically unsaturated monomer other than maleic acid, in particular a copolymer of maleic acid and at least one alkyl vinyl ether, such as ethylene and / or propylene and / or methyl vinyl ether, a copolymer of vinylphosphonic acid and at least one ethylenically unsaturated monomer other than vinylphosphonic acid, in particular a copolymer of (meth)acrylic acid and vinylphosphonic acid, and a copolymer of (meth)acrylic acid and 3. The method according to claim 1 or 2, wherein the modified vinyl alcohol is selected from copolymers of vinylphosphonic acid and maleic acid, vinyl alcohol homopolymers, copolymers of vinyl alcohol and at least one ethylenically unsaturated monomer other than vinyl alcohol, vinylphenol homopolymers, copolymers of vinylphenol and at least one ethylenically unsaturated monomer other than vinylphenol, copolymers of vinylmercaptoethanol and at least one ethylenically unsaturated monomer other than vinylmercaptoethanol, homopolymers and copolymers of vinylphenol and / or vinyl alcohol modified with at least one amine, preferably at least one primary amine, such as N-ethanolamine and / or N-methylglucamine, and mixtures thereof.

7. the at least one water-soluble polymer used as component a1) is selected from (meth)acrylic acid homopolymers, in particular acrylic acid homopolymers, copolymers of (meth)acrylic acid and at least one ethylenically unsaturated monomer other than (meth)acrylic acid, in particular copolymers of (meth)acrylic acid and maleic acid, copolymers of maleic acid and at least one ethylenically unsaturated monomer other than maleic acid, in particular copolymers of maleic acid and at least one alkyl vinyl ether, such as ethylene and / or propylene and / or methyl vinyl ether, vinyl alcohol homopolymers, copolymers of vinyl alcohol and at least one ethylenically unsaturated monomer other than vinyl alcohol, homopolymers and copolymers of vinylphenol and / or vinyl alcohol modified with at least one amine, preferably at least one primary amine, such as N-ethanolamine and / or N-methylglucamine, and mixtures thereof, 3. The method according to claim 1 or 2, wherein the polymer is preferably selected from N-methylglucamine-modified poly(vinylphenol), N-ethanolamine-modified poly(vinylphenol), poly(maleic acid-co-vinyl methyl ether), poly(maleic acid-co-acrylic acid), polyacrylic acid, poly(vinylphosphonic acid-co-acrylic acid), poly(acrylic acid-co-maleic acid-co-vinylphosphonic acid), poly(acrylic acid-co-maleic acid-co-vinylmercaptoethanol), and mixtures thereof.

8. 3. The method according to claim 1 or 2, wherein the aqueous acidic composition used in step 1) further comprises as at least one component a2) zinc cations in an amount preferably in the range of 0.1 to 8.0 g / L, even more preferably 0.2 to 6.0 g / L, even more preferably 0.3 to 5.0 g / L, even more preferably 0.5 to 3.0 g / L, in each case calculated as the metal.

9. (i) the aqueous acidic composition used in step 1) comprises at least one of components a3) and a4), preferably both a3) and a4), or only a4), i.e. as at least one component a3) at least one metal cation selected from the group of titanium ions, zirconium ions and hafnium ions, and mixtures thereof, preferably at least one metal cation selected from titanium ions and zirconium ions, and mixtures thereof, in an amount in the range of preferably 5 to 5000 ppm, more preferably 7.5 to 4000 ppm, even more preferably 10 to 3000 ppm, even more preferably 12.5 to 2000 ppm, even more preferably 15 to 1000 ppm, particularly preferably 17.5 to 500 ppm, very particularly preferably 20 to 300 ppm, and most preferably 30 to 200 ppm, in each case calculated as metal, and / or as at least one component a4) manganese cations, in an amount preferably in the range of 0.1 to 5.0 g / L, more preferably 0.1 to 4.0 g / L, even more preferably 0.2 to 3.5 g / L, even more preferably 0.3 to 3.0 g / L, and even more preferably 0.5 to 2.5 g / L, in each case calculated as the metal, Including, Optionally, free fluoride anions as at least one optional component a5), and / or at least one organosilane as optional component a6), preferably in an amount ranging from 10 to 200 ppm; or or (ii) the aqueous acidic composition used in step 1) comprises at least component a7), i.e. As at least one component a7), in each case P ２ O ５ phosphate anions in an amount preferably in the range of 1 to 150 g / L, more preferably 2.0 to 125 g / L, even more preferably 3.0 to 100 g / L, even more preferably 4.0 to 95 g / L, and even more preferably 5.0 or 7.5 to 90 g / L, calculated as and optionally As at least one component a4), manganese cations in an amount preferably in the range of 0.1 to 5.0 g / L, more preferably 0.1 to 4.0 g / L, even more preferably 0.2 to 3.5 g / L, even more preferably 0.3 to 3.0 g / L, and even more preferably 0.5 g / L to 2.5 g / L, in each case calculated as the metal. further comprising In case (i), preferably the phosphate anion a7) is absent, 3. The method according to claim 1 or 2, wherein in case (ii), the acidic aqueous composition is preferably free or essentially free of free fluoride anions a5).

10. 3. The method according to claim 1 or 2, wherein the at least one thermoplastic polymer material TM1 and the at least one thermoplastic polymer material TM2 are independently selected from polyamides, polyesters, in particular PET and / or PBT, polyurethanes, polycarbonates, polyolefins, in particular polypropylene and polyethylene, and mixtures thereof, preferably the at least one thermoplastic polymer material TM2 is selected from polyamides, in particular polyamides compounded with at least one rubber material, and preferably the at least one thermoplastic polymer material TM1, if present, is selected from polyolefins, in particular polypropylene and / or polyethylene.

11. A metal-plastic hybrid material obtainable by the method according to claim 1.

12. 1. Use of a water-soluble polymer as defined above in claim 1, when present as component a1) in an acidic aqueous composition, preferably in an acidic aqueous composition as defined in claim 1, for adhering a metal surface of a substrate at least partly made of at least one steel and / or zinc and / or at least one alloy thereof to a thermoplastic polymer material present on said surface in the form of a foil or applied thereto by injection molding.

13. a substrate having at least one metallic surface made at least in part from at least one steel and / or zinc and / or at least one alloy thereof; a film or dried or hardened layer at least partially applied on the metal surface, the film or dried or hardened layer being obtainable from at least partially applying an aqueous acidic composition onto the metal surface as defined in relation to step 1) in claim 1; Optionally, at least one thermoplastic polymer material TM1 applied at least partially in the form of a foil onto said film or dry layer or cured layer, preferably as defined in optional step 2) of claim 1, and Preferably, as defined in step 3) of claim 1, at least one thermoplastic polymer material TM2 in a form obtainable from injection molding, which is applied at least partially onto the film or the dried or cured layer, or onto the foil, if present, and which is the same or different from the thermoplastic polymer material TM1. A metal-plastic hybrid material comprising:

14. the film or dried layer or cured layer obtainable from applying the aqueous acidic composition, preferably the dried layer or cured layer has a dried layer thickness in the range of 100 to 1000 nm, and / or the film or dried layer or cured layer obtainable from applying the aqueous acidic composition, preferably the dried layer or cured layer, has a thickness in the range of 100 to 1000 nm, and / or the film or dried layer or cured layer obtainable from applying the aqueous acidic composition, preferably the dried layer or cured layer, has a thickness in the range of 100 to 1000 nm, and / or ２ O ５ Calculated as 1 to 90 mg / m ２ , more preferably 5 to 85 mg / m ２ , and even more preferably 10 to 80 mg / m ２ , and even more preferably 15 to 75 mg / m ２ and / or 0.5 to 10 mg / m2 of phosphorus, calculated as metal in each case, if the component a4) as defined in the acidic aqueous composition is present. ２ , more preferably 1 to 8 mg / m ２ , and even more preferably 1.5 to 7 mg / m ２ , and even more preferably 2 to 6 mg / m ２ 14. The metal-plastic hybrid material of claim 11 or 13, having a coating mass determined by XRF (X-ray fluorescence spectroscopy) of manganese of 0.1 wt.

15. Use of the metal-plastic hybrid material according to claim 11 or 13 as a part in the automotive or construction industry.

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