Lysine-based polymer-containing composition used for chemical pretreatment of metal substrates

Abstract

The present invention relates to a chemical pretreatment method comprising at least step 1), i.e., contacting at least one metal surface of at least one substrate with an aqueous acidic composition AC suitable for forming a coating film on at least a portion thereof, wherein AC comprises water and at least components a1) and a2), i.e., component a1) is at least one of zirconium, titanium, and hafnium cations, and component a2) is at least one lysine homopolymer and / or copolymer having an amide bond. The present invention further relates to a chemically pretreated substrate obtainable by this method, the aqueous composition AC itself, concentrates usable for its preparation, a method for using composition AC for corrosion prevention and / or imparting or improving adhesion, a method for coating the chemically pretreated substrate, and a coated substrate obtainable by this method.

Description

[Technical Field]

[0001] The present invention relates to a method for chemically pre-treating the surface of a metal substrate, a chemically pre-treated substrate obtainable by this method, a chemical pre-treatment composition usable in this method, a concentrate from which the composition can be obtained, a method for using the chemical pre-treatment composition for corrosion prevention and / or imparting or improving adhesion, a method for coating the chemically pre-treated substrate, and a coated substrate obtainable by this method. [Background technology]

[0002] Before painting a substrate with a metal surface, that is, before forming a permanent coating layer on its surface, it is now common practice to apply a corrosion-preventive chemical pretreatment using a suitable chemical pretreatment composition.

[0003] EP 0 319 018 A2 discloses a metal treatment solution containing a polyphenol derivative, such as an amine oxide-containing polyphenol. WO 01 / 66827 A1 relates to a method for corrosion-resistant treatment of non-ferrous metal substrates in particular using an aqueous solution containing an organic polymer, such as a poly-4-vinylphenol-based polymer-containing solution.

[0004] However, the use of the treatment solutions disclosed in EP 0 319 018 A2 and WO 01 / 66827 A1 is undesirable because the polyphenols described therein, particularly nitrogen-containing polyphenols, are generally considered toxic or at least harmful, and even if they were usable from the standpoint of applicable regulations, they would result in ecological and economic disadvantages. Furthermore, the polyphenols disclosed in EP 0 319 018 A2 and WO 01 / 66827 A1 are also disadvantageous because they are not biodegradable, particularly due to their aromatic structure. Moreover, the method disclosed in WO 01 / 66827 A1 is disadvantageous in that its use is limited to non-ferrous substrates and therefore does not include the use of steel substrates or polymetallic substrates containing steel.

[0005] Environmentally adaptable thin-film pretreatment systems are also well known as prior art. These are, for example, based on oxides of zirconium, titanium, cerium, molybdenum, vanadium, tungsten, and other transition metals, and are used as substitutes for harmful components such as chromium and nickel, which have been used for decades in trivalent or hexavalent chromates and trivalent cationic zinc phosphate coatings. Zirconium and titanium, in particular, have been used in a wide range of pretreatment applications due to their high chemical stability under oxygen or acidic corrosion conditions. For example, aqueous solutions based on metal complex fluorides, such as titanium and / or zirconium complex fluorides, are used as chemical pretreatment compositions to form a chemical conversion coating layer on the metal surface of a substrate. Optionally, these systems further include adhesion promoters or corrosion inhibitors such as organosilanes, organophosphonates, and amino-functional alcohols. Along with the aforementioned inorganic compounds, these additives provide excellent adhesion between the metal surface and subsequent organic coatings, such as electrodeposition, powder coating, and wet coating. Furthermore, they can enhance the barrier properties of the layer against the diffusion of corrosive ions, and against the diffusion and migration of corrosive species to or along the metal surface, otherwise these barrier properties result in the suppression of cathode delamination during the corrosion process.

[0006] Conventional thin-film pretreatment systems often exhibit sufficient corrosion protection for metal substrates such as aluminum alloys, galvanized steel sheet surfaces, and zinc-magnesium alloys. However, on steel sheet surfaces, they still provide insufficient corrosion inhibition compared to chromate or trivalent zinc phosphate chloride coatings. Furthermore, conventional thin-film pretreatment systems contain nitrogen oxides or phosphorus-containing anionic components (N) such as nitrates or phosphates. x O y z- , P x O y z-These often contain nitrates and / or phosphates, and when released into the environment in large quantities, they can cause eutrophication of water quality. Due to this effect, the use of systems containing nitrates and / or phosphates is already subject to legal regulations in some countries, such as present-day China.

[0007] Therefore, there is a need to provide chemical pretreatment compositions suitable for forming a thin, permanent coating layer on a metal substrate, particularly an iron-based substrate such as a steel substrate, or a polymetallic substrate containing at least a portion of steel. These compositions are less toxic and harmful than conventional compositions, utilize readily available components, and have higher biodegradability. However, they achieve at least equivalent, preferably even improved, corrosion resistance and / or water resistance, while simultaneously providing superior adhesion to the substrate and to any layer applied as a top layer, compared to conventional aqueous coating compositions known in the prior art. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] EP 0 319 018 A2 [Patent Document 2] WO 01 / 66827 A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Therefore, an object of the present invention is to provide chemical pretreatment compositions suitable for forming a thin permanent coating layer on a metal substrate, particularly an iron-based substrate such as a steel substrate, or a polymetallic substrate containing at least a portion of steel. These compositions are less toxic and harmful than conventional compositions, utilize readily available components, and have higher biodegradability, while achieving at least equivalent, preferably even improved, corrosion resistance and / or water resistance compared to conventionally used aqueous coating compositions known in the prior art, and simultaneously providing excellent adhesion to the substrate and to any layer to which it is applied as a top layer. [Means for solving the problem]

[0010] This objective is addressed by the subject matter of the claims of this application and its preferred embodiments disclosed herein, i.e., the subject matter described herein.

[0011] The first subject of the present invention is a method for chemically pre-treating at least one metal surface of at least one substrate, comprising at least step 1), and optionally one or more of steps 2) and / or 3), i.e. 1) A step of bringing at least one metal surface of the at least one substrate into contact with an aqueous, preferably acidic, composition AC suitable for forming a coating on the surface, at least in part, A water-based, preferably acidic, composition AC comprises, in addition to water, at least two different components a1) and a2), namely, As constituent component a1), at least one of zirconium, titanium, and hafnium cations, Component a2) preferably includes at least one lysine homopolymer and / or copolymer having an amide bond, Processes including, 2) Optionally, rinse the coating film obtained after step 1) at least once with at least one aqueous rinsing composition ARC, which is different from the aqueous, preferably acidic, composition AC, and 3) Optionally, the optionally rinsed coating film obtained after step 1) or 2) is cured or dried to obtain a cured or dried coating layer. It includes.

[0012] A further subject of the present invention is a chemically pretreated substrate that can be obtained by the chemical pretreatment method of the present invention defined above and below.

[0013] A further subject of the present invention is an aqueous, preferably acidic composition AC related to step 1), which contains, in addition to water, at least one of zirconium, titanium, and hafnium cations as component a1), and at least one lysine homopolymer and / or lysine copolymer having preferably an amide bond as component a2), as defined above and below.

[0014] A further subject of the present invention is a concentrate that can be obtained at least by dilution with water and optionally further pH adjustment of the aqueous, preferably acidic composition AC.

[0015] A further subject of the present invention relates to the use method of at least one lysine homopolymer and / or lysine copolymer defined above and below as component a2) of the composition AC when incorporated into the aqueous composition AC, more preferably the aqueous, preferably acidic composition AC of the present invention defined above and below, for imparting or improving corrosion resistance to the metal surface of the substrate, and / or for imparting or improving the adhesion of the metal surface of the substrate to one or more further coating layers present thereon.

[0016] A further subject of the present invention is a method for coating at least one chemically pretreated metal surface of at least one substrate, wherein the chemical pretreatment of the at least one metal surface is carried out according to the chemical pretreatment method of the present invention defined above and below, or by using the aqueous, preferably acidic composition AC of the present invention, and the coating method comprises at least step 4), that is 4) Applying at least one coating material composition comprising at least one film-forming polymer and / or resin to a film that has been optionally rinsed after step 1) or 2) as defined above and below, or to a dried or cured film, preferably a dried film, which can be obtained by drying or curing a film that can be obtained from any step 3) as defined above and below. It also includes.

[0017] A further subject of the present invention is a substrate, which is a coated substrate that can be obtained by the coating method of the present invention as defined above and below.

[0018] Particularly surprising, composition AC was found to be suitable for use as a chemical pretreatment composition for forming a thin permanent coating layer, such as a chemical conversion coating layer, on metal substrates, including iron-based substrates such as steel substrates, or polymetallic substrates containing at least a portion of steel.

[0019] Furthermore, and surprisingly, composition AC was found to be less toxic and harmful than the compositions of the prior art, and was able to utilize readily available components, particularly biodegradable lysine homopolymer and / or copolymer components a2) based on the naturally occurring amino acid lysine.

[0020] Furthermore, and particularly surprisingly, composition AC was found to be effectively usable as a chemical pretreatment composition in chemical pretreatment methods, and chemically pretreated substrates, or chemically pretreated substrates having a further coating layer such as an electroplated coating layer, exhibited excellent corrosion resistance. In this regard, and particularly surprisingly, this effect was found to be attributable to the presence of lysine homopolymers and / or lysine copolymers in composition AC.

[0021] Furthermore, and particularly surprisingly, it was found that composition AC could be effectively used as a chemical pretreatment composition in a chemical pretreatment method, and that the chemically pretreated substrate not only exhibited excellent substrate adhesion, but also excellent adhesion to any layer applied on top, especially to the electrodeposition coating layer applied on top of the chemical pretreatment layer. In this regard, and particularly surprisingly, it was found that this effect was due to the presence of lysine homopolymers and / or copolymers in composition AC.

[0022] Furthermore, the remarkable effects on corrosion resistance and adhesion mentioned above were observed not only on aluminum alloys but also on various metal surfaces, including steels with galvanized coatings. Therefore, surprisingly, composition AC was found to be able to effectively form a conversion layer not only on steel but also on multi-metallic substrates.

[0023] Finally, it was found that composition AC, in addition to its suitability as a chemical pretreatment composition, can also be used as a cleaning composition in a cleaning step preceding, for example, step 1). This makes it possible to use only a single composition for the entire pretreatment method. When composition AC is used as a cleaning composition, it is preferable that it contains at least one surfactant, for example, at least one nonionic surfactant. [Modes for carrying out the invention]

[0024] In the present invention, the term "contains" preferably means "consisting of," for example, as used in the present invention or in relation to the aqueous composition AC of the present invention. For example, with respect to the aforementioned composition, in addition to all the essential components present therein, one or more further optional components described below may also be included. Each component may be present in the preferred embodiments specified below.

[0025] The total mass of each component present in each composition is 100% based on the percentage (mass) of the constituent components shown below.

[0026] Pretreatment method including chemical pretreatment step 1) The first subject of the present invention is a method for chemically pre-treating at least one metal surface of at least one substrate, comprising at least step 1), and optionally one or more steps 2) and / or 3). This method may include further steps performed before step 1) and / or after each of steps 1), 2), and 3).

[0027] Chemical pretreatment is a term well known to those skilled in the art, and is particularly a part of pretreatment methods.

[0028] As used herein, the term “pretreatment” is preferably used in accordance with the term “surface pretreatment” as defined in Roempp Lexikon, “Lacke und Druckfarben” (Publisher: Ulrich Zorll, Editor: Hans-Juergen P. Adler-Stuttgart; New York: Thieme, 1998; Term: “Oberflaechenvorbehandlung”, p. 417). In a metal substrate or a substrate having a metal surface, according to DIN 50902:1994-07, the first step (one or more) of surface treatment is often one or more (chemical) cleaning steps (one or more) with an aqueous or non-aqueous cleaning composition (also called “surface preparation steps”). Thus, as will be described later, this method may include one or more further optional steps performed prior to step 1).

[0029] The term "chemical pretreatment" is used in accordance with EN ISO 4618:2006 (E / F / D) (Term: 2.41 "Chemical pretreatment"), and it refers to any chemical treatment applied to a surface before the application of a coating material. According to this standard, treatments that can be included in the term "conversion treatment," such as chromate treatment, phosphate treatment, and oxalate treatment, belong to chemical pretreatment and are therefore distinguished from the (subsequent) coating process, where the coating material, i.e., coating composition, such as powder coating composition, electrodeposition coating composition, or aqueous or non-aqueous liquid coating material, applies. In addition to conversion treatments such as chromate treatment and phosphate treatment, chemical surface pretreatment is generally achieved by passivation compositions and thin-film forming compositions, including aqueous composition AC, which is essentially used as the chemical pretreatment composition in step 1). Thus, step 1) of this method represents the chemical pretreatment step, and the aqueous composition AC used therein represents the chemical pretreatment composition.

[0030] In accordance with the above internationally valid definition of "pretreatment" of metal substrates, the pretreatment method according to the present invention preferably includes a surface preparation cleaning step in addition to the chemical pretreatment step 1).

[0031] Preferably, the pretreatment method does not include any steps involving treatment with chromium ions such as Cr(VI) ions and / or Cr(III) ions.

[0032] Preferably, chemical pretreatment step 1) is the only chemical pretreatment step in the pretreatment method. Therefore, preferably, no chemical pretreatment composition other than the aqueous composition AC applied in step 1) is used.

[0033] The film obtained after step 1) or any step 2) and / or 3) contains, in each case, trace elements (one or more) such as Ti, Zr, and / or Si, as determined by XRF measurement by the method described in the "Methods" section of this specification, preferably 0.5 to 500 mg / m². 2, more preferably 1 to 400 mg / m 2 , even more preferably 2 to 350 mg / m 2 and has a coating mass in the range. Preferably, the cured or dried coating layer obtained after any step 3) has a dry film thickness of less than 0.5 μm.

[0034] Substrate The substrate used in step 1) includes at least one metal surface. The term "metal surface" in the present invention preferably means that the surface of the substrate used is at least partially composed of at least one metal, that is, at least one region of the surface is composed of at least one metal and / or its alloy. Preferably, the entire surface of the substrate is composed of at least one metal and / or its alloy, and more preferably, the entire substrate is composed of at least one metal and / or its alloy, that is, the substrate consists of at least one metal and / or its alloy. When the substrate includes regions of different metals, the substrate is referred to herein as a "multi-metal substrate" as a subclass of metal substrates. Such a multi-metal substrate can be subjected to step 1) of the chemical pretreatment method and can be coated in the same treatment tank.

[0035] At least one metal surface of the substrate may optionally be pre-coated, but is preferably not pre-coated.

[0036] Preferably, the substrate used is a conventionally used and well-known conductive substrate to those skilled in the art. The substrate can have any shape such as coils, foils, sheets, etc., and can represent vehicle parts such as automotive parts, for example, wheel parts. Particularly suitable substrates are production automotive body parts or finished vehicle bodies.

[0037] Preferably, at least one surface of the substrate is at least partially composed of at least one metal and / or its alloy, more preferably at least partially composed of at least one of steel, steel alloys, aluminum, aluminum alloys, zinc, zinc alloys including zinc-magnesium alloys, and mixtures thereof, and even more preferably at least partially composed of at least one of steel and steel alloys. Examples of steel and / or steel alloys include base steel, cold-rolled steel (CRS), hot-rolled steel (HRS), galvanized steel (electro-galvanized steel), e.g., hot-dip galvanized steel (HDG), electro-galvanized steel (EG), alloy-galvanized steel, and aluminum-plated steel, e.g., Galvalume®, Galvannealed®, or Galfan®, and steel at least partially coated with at least one zinc-aluminum-magnesium alloy (ZM). Examples of aluminum alloys include aluminum-magnesium alloys, aluminum-magnesium-silicon alloys, aluminum-copper alloys, aluminum-zinc alloys, and aluminum-zinc-copper alloys. Examples of zinc alloys include Zn / Mg alloys, Zn / Ni alloys, and Zn / Mg / Al alloys.

[0038] Any step performed before step 1) As stated above, and in accordance with the above internationally valid definition of "pretreatment" of metal substrates, the pretreatment method according to the present invention preferably includes a cleaning step to prepare the surface in addition to the chemical pretreatment step 1).

[0039] Before step 1), one or more of the following steps may be performed in this order: Step A-1): A step of cleaning the surface of the substrate and optionally rinsing it afterward. Step B-1): The substrate surface is subjected to acidic or alkaline pickling, i.e., etching, and then the substrate surface is rinsed. Step C-1): A step of bringing the substrate surface into contact with an aqueous composition containing at least one mineral acid (the aqueous composition being different from compositions AC and ARC), or an alkaline aqueous composition or a pH-neutral aqueous composition (each of these compositions being different from compositions AC and ARC), Step D-1): A step of rinsing the surface of the substrate obtained after contact according to Step C-1) and / or B-1).

[0040] Alternatively, steps A-1) and B-1) can be carried out in a single step, which is preferable. Preferably, both steps A-1) and B-1) are carried out. An optional step C-1) preferably removes oxides, unwanted alloy components, skin (film), brushing dust, etc., from the substrate surface, thereby activating the surface for the subsequent chemical conversion treatment in step 1). Preferably, at least one mineral acid in step C-1) is sulfuric acid and / or nitric acid, more preferably sulfuric acid. As will be described later, in step A-1), a cleaning composition different from or identical to composition AC may be used.

[0041] Any rinsing that is part of rinsing steps D-1) and A-1) is preferably carried out using deionized water or tap water. Preferably, step D-1) is carried out using deionized water.

[0042] In the cleaning process A-1), an aqueous composition AC may be used as the cleaning composition. In this case, the cleaning process is preferably carried out by spraying.

[0043] Process 1) According to step 1), at least one metal surface of at least one substrate is at least partially brought into contact with an aqueous composition AC suitable for forming at least a partial coating on the surface. The aqueous composition AC represents a chemical pretreatment composition. By performing step 1), a chemical conversion film (or chemical conversion coating film or passivation film) is formed on the surface of the substrate that has come into contact with the aqueous composition AC. If a cleaning step has been performed before step 1), preferably the cleaned portion of the substrate surface is subjected to step 1).

[0044] The term "at least partially" preferably means, in this context, according to the general understanding of the term, that it may be desirable or sufficient to contact the chemical pretreatment composition AC with the entire surface of the substrate rather than the entire surface. When only a portion of the metal surface is in contact with each composition, it is usually the same portion throughout the entire process. However, generally, it is desirable to contact the entire surface of the metal substrate with each composition.

[0045] The "contact" in step 1) can be a spray, dipping, or roll coating process. Composition AC can also be applied by flooding the surface, or by manual wiping or brushing. Spraying or dipping is preferred.

[0046] The processing time, i.e., the period during which the surface is in contact with the aqueous composition AC in step 1), is preferably 1 second to 20 minutes, more preferably 15 seconds or 30 seconds to 10 minutes, most preferably 45 seconds to 5 minutes, for example, 1 to 3 minutes.

[0047] The temperature of the aqueous composition AC used in step 1) is preferably 5 to 50°C, more preferably 15 to 45°C or 40°C, and most preferably 25 to 35°C.

[0048] The aqueous composition AC can be used as an immersion coating bath. However, as outlined in relation to step 1) above, it can also be applied by substantially any conventional coating method, such as spray coating, roll coating, brush application, and wiping. Spraying and immersion are preferred.

[0049] Preferably, the film obtained after step 1) (preferably after drying by any step 3)) is measured by XRF (X-ray fluorescence analysis), and the coating mass is calculated as metal or element, with a total coating mass of 0.5 to 500 mg / m². 2 More preferably 1-400 mg / m² 2 More preferably 2 to 350 mg / m² 2 Most preferably 3 to 300 mg / m² 2 It has a coating mass of silicon, zirconium, titanium, and / or hafnium ions.

[0050] Aqueous composition AC used in step 1) The aqueous composition AC contains water, plus at least two components a1) and a2), which are different from each other. Component a1) includes at least one of zirconium, titanium, and hafnium cations. Component a2) includes at least one lysine homopolymer and / or lysine copolymer. The aqueous composition AC used in step 1) represents the “pretreatment composition” or “chemical pretreatment composition”.

[0051] Preferably, the aqueous composition AC is an aqueous acidic composition and has a pH value in the range of 0.1 to less than 7.0, more preferably 0.5 to 6.5, more preferably 1.0 to 6.0, even more preferably 1.5 or 2.0 to 5.5, even more preferably 2.5 or 3.0 to 5.25, and most preferably 3.5 or 4.0 to 5.0. The pH value can be adjusted in particular using appropriate pH adjusting components, especially sodium hydroxide and / or potassium hydroxide and / or sodium carbonate and / or potassium carbonate and / or ammonium carbonate for alkalinity adjustment, and if acidity adjustment is required, it can be specifically adjusted using at least one inorganic acid such as phosphoric acid and / or sulfuric acid and / or boric acid and / or nitric acid, and / or at least one organic acid such as methylsulfonic acid.

[0052] The aqueous composition AC may be a dispersion or a solution. Preferably, it is a solution. Solubility is measured at 20°C and atmospheric pressure (1.013 bar).

[0053] The aqueous composition AC used in step 1) preferably has a temperature in the range of 5 to 50°C, more preferably 15 to 45°C or 40°C, and most preferably 25 to 35°C.

[0054] The aqueous composition AC used in step 1) is preferably, It does not contain, or substantially does not contain, chromium ions, such as Cr(VI) cations and / or Cr(III) cations, more preferably it does not contain chromium ions, or the maximum content of chromium ions calculated as metal is less than 10 mg / L, and / or preferably, It does not contain nickel ions, such as Ni(II) cations and / or Ni(III) cations, or is substantially free of them, more preferably does not contain nickel ions, or has a maximum content of nickel ions calculated as metal of less than 10 mg / L, and / or, preferably, It does not contain or substantially contains boron ions, such as B(III) cations and / or B(IV) cations, more preferably it does not contain boron ions, or the maximum content of boron ions calculated as boron is less than 10 mg / L, and / or preferably, It is free of nitrate anions, substantially free of nitrate anions, more preferably free of nitrate anions, or has a maximum content of nitrate anions calculated as nitrates of less than 10 mg / L, and / or preferably, It does not contain phosphate anions, or substantially does not contain them, and more preferably does not contain phosphate anions, or the maximum content of phosphate anions calculated as phosphate is less than 10 mg / L.

[0055] In this context, "substantially absent" means, in all cases, that the aforementioned components are not intentionally added, but it does not rule out the presence of any residue of any component as an impurity, and / or in amounts naturally present in water.

[0056] In the sense of the present invention, the term "aqueous" in relation to aqueous composition AC used in step 1) preferably means that the composition contains at least 50% by mass, more preferably at least 60% by mass, even more preferably at least 70% by mass, particularly at least 80% by mass, and most preferably at least 90% by mass of water, based on the total content of organic solvents including water and inorganic solvents. Therefore, the aqueous composition may contain at least one organic solvent in addition to water, but in an amount less than that of water. Preferably, aqueous composition AC does not contain or substantially contains no organic solvents.

[0057] Preferably, the aqueous composition AC contains, based on its total mass, at least 50% by mass, preferably at least 60% by mass, more preferably at least 70% by mass, particularly at least 80% by mass, and most preferably at least 90% by mass of water.

[0058] Preferably, the aqueous composition AC is free of or substantially free of organic solvents. "Substantially free" means that organic solvents are not intentionally added, but the possibility of their presence as impurities is not ruled out. Preferably, the amount of organic solvent present in the aqueous composition AC is not more than 5% by mass, more preferably not more than 2.5% by mass, even more preferably less than 2.0% by mass, and most preferably a maximum of 1.0% by mass, or a maximum of 0.5% by mass, or a maximum of 0.1% by mass, based on the total mass of the composition.

[0059] Component a1) In aqueous composition AC, component a1) contains at least one of zirconium, titanium, and hafnium cations, preferably at least one of zirconium and titanium cations, and more preferably at least one zirconium cation.

[0060] Preferably, the aqueous composition AC contains at least one of zirconium, titanium, and hafnium cations, calculated as a metal in each case, in an amount ranging from 1 or 5 to 4000 mg / L, more preferably 7.5 to 2000 mg / L, even more preferably 10 to 1500 mg / L, even more preferably 12.5 to 1000 mg / L, even more preferably 15 to 750 mg / L, and most preferably 20 to 500 mg / L.

[0061] Preferably, a precursor metal compound is used to generate at least one metal cation present in composition AC as component a1). Preferably, the precursor metal compound is water-soluble. Solubility is measured at a temperature of 20°C and atmospheric pressure (1.013 bar). Particularly preferred zirconium, titanium, and / or hafnium compounds for use as precursor compounds are complex fluorides of these metals. The term "complex fluoride" includes single and multiple protonated and deprotonated forms. It is also possible to use mixtures of such complex fluorides. In the present invention, a complex fluoride refers to a complex of a metal cation, such as zirconium, titanium, and / or hafnium cations and a fluoride ion, formed, for example, by the coordination of a fluoride anion to a zirconium, titanium, and / or hafnium cation in the presence of water. When at least one complex fluoride of zirconium, titanium, and / or hafnium cations is used as a precursor compound, the aqueous composition further contains a fluoride anion as component a3).

[0062] Furthermore, or alternatively, zirconium can also be added in the form of zirconyl compounds, such as zirconyl nitrate, zirconyl acetate, zirconium carbonate, and / or zirconium nitrate, the latter being particularly preferred when the aqueous composition is acidic. The same applies to titanium and hafnium.

[0063] The content of at least one metal cation a1) can be monitored and measured by ICP-OES (inductively coupled plasma atomic emission spectroscopy). The method is described in the "Methods" section below.

[0064] Component a2) In aqueous composition AC, at least one lysine homopolymer and / or lysine copolymer, preferably a lysine homopolymer, is present as component a2).

[0065] Preferably, at least one lysine homopolymer and / or lysine copolymer is present in composition AC in an amount ranging from 1 to 500,000 mg / L, more preferably 2 to 300,000 mg / L, even more preferably 3 to 200,000 mg / L, even more preferably 4 to 100,000 mg / L, even more preferably 5 to 50,000 mg / L, even more preferably 6 to 20,000 mg / L, even more preferably 7 to 15,000 mg / L, even more preferably 7.5 to 10,000 mg / L, even more preferably 8 to 5,000 mg / L, even more preferably 9 to 2,500 mg / L or 2,000 mg / L, even more preferably 10 to 1,000 mg / L, and most preferably 15 or 20 to 500 mg / L.

[0066] Preferably, at least one lysine homopolymer and / or lysine copolymer present as component a2) in composition AC has a mass-average molecular weight in the range of 500 to 300,000 g / mol or 20,000 g / mol, more preferably 750 to 200,000 g / mol or 15,000 g / mol, even more preferably 1,000 to 100,000 g / mol or 10,000 g / mol, even more preferably 1,500 to 75,000 g / mol or 7,500 g / mol, and most preferably 2,000 to 50,000 g / mol or 5,000 g / mol.

[0067] The lysine homopolymers and / or lysine copolymers (also commonly referred to herein as lysine polymers or polylysine in this context) used in the present invention contain at least structural units derived from the amino acid lysine. The lysine polymers, in particular polylysine homopolymers, used in the present invention may differ in terms of stereochemistry (D / L). Since the L-form of the amino acid lysine is a naturally occurring form, the lysine polymers used in the present invention preferably contain structural units derived from the amino acid lysine having at least an L-form structure. Furthermore, the lysine polymers, in particular polylysine homopolymers, used in the present invention may differ in their binding position (α / ε; position relative to the carbon atom having the amino group in lysine). Since the ε position is the natural form, the lysine polymers used in the present invention preferably contain structural units derived from the amino acid lysine having at least an ε-binding position. Most preferred are ε-poly-L-lysine polymers, in particular the corresponding homopolymers. At least one lysine homopolymer and / or lysine copolymer, preferably lysine, for example ε-polylysine, and especially ε-poly-L-lysine (EPL), is preferably manufactured as a polymer containing at least 10, up to 100, more preferably at least 15, up to 75, even more preferably at least 20, up to 50, and even more preferably more than 20, for example at least 25, up to 40, for example up to 30 lysine units (e.g., L-lysine units). The precursor amino acid lysine contains a total of two amino groups, one on the α-carbon and one on the ε-carbon. ε-poly-L-lysine is used, for example, as a natural preservative having antimicrobial effects against certain yeasts, fungi, Gram-positive bacteria, and Gram-negative bacteria. It can be used in food products, the chemical industry, and the pharmaceutical industry.

[0068] At least one lysine homopolymer and / or lysine copolymer, preferably a lysine homopolymer (lysine homopolypeptide), preferably has a cationic charge and therefore belongs to the cationic polymer group. This is because polylysine contains positively charged hydrophilic amino groups at pH 7.

[0069] Preferably, the lysine homopolymers and / or lysine copolymers used in the present invention have an amide bond formed by the reaction of a carboxyl group of one lysine monomer with an amino group of another lysine monomer, where the amino group of the other lysine monomer is preferably bonded to its ε-carbon atom. In the case of copolymers, in addition to lysine, monomers suitable for their preparation are preferably selected from monomers having at least one amino group and / or carboxyl group.

[0070] Preferably, at least one lysine homopolymer and / or lysine copolymer has an amino group, and more preferably, it is at least partially derived from the lysine monomer used in its production.

[0071] The lysine homopolymers and / or lysine copolymers used in the present invention, particularly lysine homopolymers, can be produced, for example, using bacterial strains of the genus Streptomyces, which are also used in natural fermentation and the commercial production of, for example, ε-polylysine, or ε-poly-L-lysine. They typically have high heat tolerance and do not denature even at high temperatures (e.g., 121°C for 30 minutes). The lysine homopolymers and / or lysine copolymers used in the present invention, particularly lysine homopolymers such as ε-polylysine, are more preferably strongly water-soluble, with a maximum solubility of at least 500 g / L. The lysine homopolymers and / or lysine copolymers used in the present invention, particularly lysine homopolymers such as ε-polylysine, have an even wider pH range (pH values ​​from 2 to 9), which can compensate for the low activity of other preservatives under neutral and alkaline conditions.

[0072] Methods for producing the lysine homopolymers and / or lysine copolymers used in the present invention, as well as lysine homopolymers and / or lysine copolymers suitable on their own, are disclosed in WO 2022 / 136613 A1.

[0073] Preferably, component a2) is a non-aromatic polymer.

[0074] Any component a3) Preferably, aqueous composition AC further contains, as component a3), a fluoride anion including a complex fluoride anion, in an amount in the range of preferably 5 or 10 to 2000 mg / L, more preferably 15 to 1500 mg / L, even more preferably 20 to 1000 mg / L, and most preferably 25 to 500 or 200 mg / L, calculated as fluorine. The complex fluoride contains zirconium.

[0075] Preferably, aqueous composition AC contains a fluoride anion present as a complex fluoride anion as component a3), which is coordinated to at least one of the zirconium, titanium, and hafnium cations present as component a1) in the composition, more preferably coordinated to at least one of the zirconium and titanium cations, and even more preferably coordinated to the zirconium cation, in an amount calculated in all cases as H2MF6 (where M is Zr, Ti, and / or Hf), more preferably in the presence of water, in the range of 1 or 50 mg / L to 4000 mg / L, more preferably 10 or 100 mg / L to 2000 or 1500 mg / L, and even more preferably 50 or 100 mg / L to 500 or 250 mg / L. Alternatively, the fluoride anion present as component a3) can be generated by adding other water-soluble fluorine compounds, such as fluorides (other than complex fluorides of Ti, Zr, and / or Hf) and hydrofluoric acid to the composition. The free fluoride content is measured using a fluoride ion-sensitive electrode according to the method disclosed in the "Methods" section.

[0076] Any component a4) Optionally, preferably, aqueous composition AC further contains, as component a4), at least one organosilane and / or its hydrolysate and / or condensation product, in any case calculated as elemental silicon, preferably in the range of 0 or 5 to 20,000 or 15,000 mg / L, more preferably 0 or 10 to 10,000 or 5,000 mg / L, even more preferably 0 or 15 to 1,000 or 500 mg / L, and even more preferably 0 or 20 to 250 or 200 mg / L.

[0077] The term "organosilane" includes, for example, organic alkoxysilanes and organic silanols. Examples of hydrolysis and / or condensation products of organic silanes include organic siloxanes and polyorganosiloxanes, as well as polyorganosilanols. In the present invention, "polyorganosiloxane" preferably means a compound that can be condensed from at least two organic silanols and does not form a polydimethylsiloxane. The "organic" in "organosilane" preferably means the presence of at least one organic group that is directly bonded to a silicon atom via a carbon atom and therefore does not undergo hydrolysis.

[0078] Preferably, any component a4) has at least one functional group selected from (meth)acrylate groups, alkylaminoalkyl groups, alkylamino groups, alkyltetrasulfide groups, amino groups, aminoalkyl groups, carboxyl groups, epoxy groups, glycidoxy groups, hydroxyl groups, isocyanate groups, mercaptoalkyl groups, succinic anhydride groups, imide groups, imino groups, and / or ureido groups (urea groups).

[0079] Examples of organosilanes include (3-aminopropyl)trimethoxysilane, (3-aminopropyl)triethoxysilane, bis(trimethoxysilylpropyl)amine, bis(triethoxysilylpropyl)amine, N-2-aminoethyl-3-aminopropyltrimethoxysilane, (3-butylaminopropyl)trimethoxysilane, bis(3-triethoxysilylpropyl)disulfide, bis(3-triethoxysilylpropyl)tetrasulfide, bis(3-trimethoxysilylpropyl)disulfide Examples include bis(3-trimethoxysilylpropyl)tetrasulfide, 1,2-bis(triethoxysilyl)ethane, (3-mercaptopropyl)trimethoxysilane, (3-mercaptopropyl)triethoxysilane, (3-methylaminopropyl)triethoxysilane, (3-methylaminopropyl)trimethoxysilane, (3-glycidyloxypropyl)trimethoxysilane and / or (3-glycidyloxypropyl)triethoxysilane and / or vinyltrimethoxysilane. Organic silanes are preferably present in hydrolyzed form.

[0080] Preferably, aqueous composition AC contains as component a4) an organic silane and / or its hydrolysate and / or condensation product having at least one amino group, urea group, imide group, imino group and / or ureido group per organic silane unit, more preferably at least one or more, for example, at least two amino groups per organic silane unit. Particularly preferred are 2-aminoethyl-3-aminopropyltrimethoxysilane, 2-aminoethyl-3-aminopropyltriethoxysilane, bis(trimethoxysilylpropyl)amine and / or bis(triethoxysilylpropyl)amine.

[0081] Any further any component including any components a5) and a6) Optionally, aqueous composition AC further comprises cations of metals from subgroups 1-3 (copper, zinc, and scandium) and subgroups 5-8 (vanadium, manganese, and iron) of the periodic table, including lanthanides, as well as at least one metal cation selected from the group consisting of main group 2 (alkaline earth metals), lithium, bismuth, and / or tin. More preferably, aqueous composition AC further comprises at least one metal cation selected from the group consisting of cerium and other lanthanides, chromium, iron, calcium, cobalt, copper, magnesium, manganese, molybdenum, nickel, niobium, tantalum, yttrium, vanadium, lithium, bismuth, zinc, tin, and mixtures thereof. Most preferably, the cation is copper and / or zinc.

[0082] Optionally, preferably, aqueous composition AC further As component a5), zinc cations are used, calculated as a metal in all cases, preferably in an amount in the range of 0 or 5 to 5000 mg / L, more preferably 0 or 10 to 2500 mg / L, and / or As component a6), copper cations are calculated as a metal in all cases, preferably in an amount in the range of 0 or 1 to 1000 mg / L, more preferably 0 or 1 to 500 mg / L, even more preferably 0 or 2 to 100 mg / L, and even more preferably 0 or 2.5 to 50 mg / L. include.

[0083] Optionally, aqueous composition AC further comprises at least one pH-adjusting component preferably selected from the group consisting of nitric acid, sulfuric acid, methanesulfonic acid, acetic acid, aqueous ammonia, sodium hydroxide, and sodium carbonate, where methanesulfonic acid and sodium carbonate are preferred. Depending on the pH value of the aqueous composition, the above components may exist in a fully or partially deprotonated or protonated form.

[0084] Optionally, aqueous composition AC further preferably comprises at least one organic solvent selected from the group consisting of methanol, ethanol, ethylene glycol N-butyl ether, ethylene glycol n-propyl ether, propylene glycol n-propyl ether, propylene glycol n-butyl ether, and mixtures thereof. Methanol and ethanol may be present, for example, as reaction products of organosilane hydrolysis.

[0085] Optionally, aqueous composition AC may further contain at least one organic acid, preferably at least two organic acids having carboxylic acid groups and / or at least one organic acid having at least one carboxylic acid group and at least one further functional group (e.g., an OH group) having at least one donor atom, such as lactic acid, especially when the aqueous composition is alkaline. The presence of such compounds is useful for stabilizing at least one metal cation present in the composition as a1) such as a Zr cation.

[0086] The aqueous composition may further include at least one of the following components: one or more waxes, one or more wetting agents, one or more defoaming agents, and / or rheological additives.

[0087] Optionally, aqueous composition AC may include at least one water-soluble polymer different from component a2), for example, a water-soluble polymer having at least one functional group selected from acidic groups, hydroxyl groups, and mixtures thereof. Preferably, if present, the at least one water-soluble polymer is a homopolymer or copolymer obtained by polymerization of at least one ethylene unsaturated monomer, wherein at least a portion of the monomer is an acidic group, more preferably a homopolymer or copolymer obtained by polymerization of at least one vinyl monomer and / or (meth)acrylic monomer (wherein at least a portion of the monomer has at least one functional group selected from acidic groups, hydroxyl groups, and mixtures thereof), and more preferably a homopolymer or copolymer obtained by polymerization of at least one vinyl monomer and / or (meth)acrylic monomer (wherein at least a portion of the monomer has at least one functional group selected from acidic groups, hydroxyl groups, and mixtures thereof).

[0088] Optionally, if aqueous composition AC is used as a cleaning composition in addition to its suitability as a chemical pretreatment composition, and especially if it represents a cleaning composition, it further comprises at least one surfactant.

[0089] The term surfactant as used herein is preferably used in accordance with the definition of "tenside" as defined in Roempp Lexikon, "Lacke und Druckfarben" (Publisher: Ulrich Zorll, Editor: Hans-Juergen P. Adler-Stuttgart; New York: Thieme, 1998; Term: "tenside", pp. 557 and 558). Surfactants exhibit antiemulsifying properties. Suitable surfactants are well known to those skilled in the art and are disclosed, for example, in WO 2020 / 200838 A1.

[0090] Preferably, at least one surfactant is selected from nonionic, anionic, and / or cationic surfactants, most preferably nonionic surfactants.

[0091] Suitable nonionic surfactants include alkylphenol alkoxylates, particularly C6-C6. 14 Alkyl phenol alkoxylates having an alkyl chain and a degree of alkoxylation of 5 to 30 moles per mole of phenol, C8-C 22 , C 10 ~C 18 Alkyl polyglucosides having an alkyl chain length and containing 1 to 20, preferably 1 to 5, glucoside units, fatty acid amide alkoxylates, fatty acid alkanol amide alkoxylates, N-alkyl glucamides, or ethylene oxide, propylene oxide and / or butylene oxide as block copolymers or random copolymers, and alkoxylated C8-C 22 Examples of block copolymers include alcohols, such as fatty alcohol alkoxylates, oxoprocess alcohol alkoxylates, and Guerbet alcohol alkoxylates (where alkoxylation is carried out using ethylene oxide, propylene oxide, butylene oxide, and / or mixtures thereof). The alcohol preferably has 8 to 18 carbon atoms, and the degree of alkoxylation is typically 2 to 50 moles, preferably 3 to 20 moles, of the above alkylene oxide per mole of alcohol. The head group of the alkylene oxide may further contain so-called terminal capping groups such as benzyl, methyl, and / or tert-butyl capping as modifications.

[0092] Depending on the application, the following anionic surfactants are particularly usable: fatty alcohol sulfates having an alkyl chain length of 8-22, preferably 10-18 carbon atoms, such as lauryl sulfate, cetyl sulfate, myristyl sulfate, palmityl sulfate, or stearyl sulfate; alkyl ether sulfates having an alkyl chain length of 8-22, preferably 10-18 carbon atoms; linear C8-C20 Alkylbenzenesulfonates, or alkanesulfonates, and soaps, for example, C8-C 24 Sodium or potassium salts of carboxylic acids. Cationic surfactants used depending on the application include quaternary mono and di(C7-C) surfactants. 25 Alkyl)dimethylammonium compounds, ester quats, especially C8-C 22 Quaternary esterified mono, di, and tri-canolamines esterified with carboxylic acids, C7-C 25 Alkylamines, N,N-dimethyl-N-(hydroxy-C7~C 25 Alkyl)ammonium salts and / or imidazoline cuts.

[0093] However, as mentioned above, at least one surfactant is preferably at least one nonionic surfactant. In most applications, anionic surfactants tend to foam too much, while cationic surfactants often adhere to metal surfaces, which can cause problems with the deposition of subsequent chemical conversion coatings.

[0094] Preferably, the aqueous composition AC contains at least one surfactant as at least one component a3) in an amount of 0 or 0.3 to 10.0 g / L, more preferably 0 or 0.4 to 5.0 g / L, and even more preferably 0 or 0.5 to 3.5 g / L.

[0095] Optional step 2) In any step 2), the film obtained after step 1) is rinsed at least once with at least one aqueous rinsing composition ARC, which is different from aqueous composition AC. Preferably, composition ARC consists of water only or is essentially water only. The term “rinsing” means, in accordance with the general understanding of the term, preferably the removal of any excess aqueous composition AC that came into contact with the surface in a step directly preceding any rinsing step.

[0096] Tap water and / or deionized water can be used for rinsing in any step 2). As mentioned above, any step 2) can be performed multiple times. Therefore, for example, it is possible to rinse once with tap water in step 2) and then rinse with deionized water, or vice versa.

[0097] Optional step 3) In any step 3), the film obtained after step 1) or any step 2) is dried or cured to obtain a cured or dried coating layer.

[0098] In particular, in step 4) described later, if the coating material composition is applied thereafter, drying and / or curing can be performed. However, step 3) is optional, and therefore, further method steps such as step 4) can be performed without drying and / or curing the film obtained after performing step 1) or rinsing step 2). In particular, in step 4) described later, the coating material composition, such as an electrodeposition paint composition, can be applied to the wet film obtained after performing step 1) or rinsing in step 2).

[0099] The drying or curing step 3) is preferably carried out at a temperature in the range of 15°C to 180°C, more preferably in the range of 25°C to 150°C, and particularly in the range of 50°C to 130°C, if performed. In the present invention, "drying" means physical drying by evaporation of water originally present in the composition used. "Curing," on the other hand, further includes chemical reactions between at least two components originally present in the composition, and / or between at least one component originally present in the composition and appropriate functional groups present on the metal surface or conversion film, for example, due to the presence of polymer a2) in composition AC. Once the film is dried, the resulting product can be considered as a layer.

[0100] Preferably, the conversion layer formed after drying or curing the film obtained after step 3) has a coating mass of 0.5 to 500 mg / m² as measured by XRF (X-ray fluorescence analysis). 2 More preferably 1-400 mg / m² 2 More preferably 2-350 mg / m² 2 In each case, these are measured by XRF as trace elements such as Ti, Zr, and / or Si.

[0101] Preferably, the thickness of the dry layer of the conversion layer formed after drying or curing the film obtained after step 3) is less than 0.5 μm. Preferably, the cured or dried coating layer obtained after step 3) has a dry film thickness in the range of 1 nm to less than 500 nm, more preferably 10 nm to 250 nm, and particularly 80 to 150 nm.

[0102] Substrates that can be obtained by chemical pretreatment methods A further subject of the present invention is a substrate which is a chemically pretreated substrate that can be obtained by the chemical pretreatment method of the present invention as defined above and below.

[0103] All preferred embodiments described herein with respect to the chemical pretreatment method and its preferred embodiments are also preferred embodiments of the substrate that can be obtained by this method.

[0104] Aqueous composition AC A further subject of the present invention is the aqueous composition AC used in step 1) of the chemical pretreatment method, as defined above and below in relation to step 1), which comprises, in addition to water, at least one of zirconium, titanium, and hafnium cations as component a1) and at least one lysine homopolymer and / or lysine copolymer as component a2).

[0105] All preferred embodiments described above with respect to the chemical pretreatment method of the present invention, the substrate that can be obtained therefrom, and preferred embodiments thereof are also preferred embodiments of composition AC of the present invention.

[0106] In particular, when an aqueous composition is used as a cleaning composition, it is preferable that it contains at least one surfactant as an optional, preferred component.

[0107] concentrate A further subject of the present invention is a concentrate that can be obtained by dilution with water and, if necessary, further pH adjustment to obtain at least an aqueous composition AC.

[0108] All preferred embodiments described herein with respect to the chemical pretreatment method of the present invention, the substrates obtainable therefrom, and the composition AC of the present invention, and preferred embodiments thereof, are also preferred embodiments of the concentrate of the present invention.

[0109] The concentrate used to produce aqueous composition AC typically contains the components of the aqueous composition AC to be produced in a desired ratio, but at a higher concentration. Such a concentrate is diluted with water to the desired concentration of the components, as described above, to form composition AC. If necessary, the pH value of the composition can be adjusted after dilution, as described above. Of course, it is also possible to further add any components of the composition to the water used for dilution, or to add any components or some essential components after diluting the concentrate with water. However, it is preferable that the concentrate already contains all the essential components.

[0110] Preferably, the aqueous composition AC is obtained by diluting the concentrate with water, preferably deionized water. In this case, the concentrate is present in the diluted composition in an amount of 5 to 60 g / L, more preferably 10 to 40 g / L, and even more preferably 15 to 30 g / L, based on the total mass of the composition obtained after dilution of the concentrate.

[0111] Preferably, the concentrate is diluted with water in a mass ratio of 1:5000 to 1:10, more preferably 1:1000 to 1:10, most preferably 1:300 to 1:10, and even more preferably 1:150 to 1:50 to produce composition AC.

[0112] Preferably, composition AC can be prepared from the concentrate by diluting the concentrate with water.

[0113] use A further subject of the present invention is a method of using at least one lysine homopolymer and / or lysine copolymer, as defined above and below, as component a2) of composition AC, preferably in aqueous composition AC, more preferably in aqueous composition AC of the present invention as defined above and below, to provide or improve corrosion resistance to a metal surface of a substrate and / or to provide or improve adhesion to one or more further coating layers present on the metal surface of a substrate.

[0114] All preferred embodiments relating to the chemical pretreatment method of the present invention, the substrates that can be obtained therefrom, the composition AC of the present invention, and the concentrates, as described above, and these preferred embodiments are also preferred embodiments of the method of use of the present invention.

[0115] Coating method A further subject of the present invention is a method for coating at least one chemically pretreated metal surface of at least one substrate, wherein the chemical pretreatment of at least one metal surface is carried out according to the chemical pretreatment method of the present invention as defined above and below, or using the aqueous composition AC of the present invention, and the coating method comprises at least step 4), i.e. 4) A step of applying at least one coating material composition comprising at least one film-forming polymer and / or resin to a film that has been optionally rinsed after step 1) or 2) as defined above and below, or to a dried or cured film, preferably a dried film, which can be obtained by drying or curing the film obtained from any step 3) as defined above and below. It also includes.

[0116] The coating method according to the present invention comprises at least step 4) and is performed after carrying out the chemical pretreatment method of the present invention as defined above and below. However, the coating method may include one or more further additional optional steps.

[0117] All preferred embodiments described above with respect to the chemical pretreatment method of the present invention, the substrates that can be obtained therefrom, the composition AC of the present invention, the concentrates, and the methods of use of the present invention, as well as these preferred embodiments, are also preferred embodiments of the coating method of the present invention.

[0118] The coating material composition used in step 4) is different from both composition AC and ARC.

[0119] The coating material composition can be, for example, an electrodeposition coating composition, a primer coating composition, a base coat composition, or a top coat comprising a clear coat composition. Of course, it is also possible to apply multiple compositions sequentially to form a multilayer coating system, which has been conventionally used, for example, in the automotive industry.

[0120] Preferably, the coating material composition applied in step 4) is an electrodepositable, preferably cationic electrodepositable, coating material composition, where at least one film-forming polymer and / or resin present is preferably an electrodepositable, preferably cationic electrodepositable polymer.

[0121] Alternatively, similarly preferably, the coating material composition applied in step 4) is a powdered coating composition comprising at least one polymer and / or resin selected from polyester, epoxy resin, poly(meth)acrylate homopolymer, and poly(meth)acrylate copolymer.

[0122] Substrates that can be obtained by coating methods A further subject of the present invention is a substrate, which is a coated substrate that can be obtained by the coating method of the present invention as defined above and below.

[0123] All preferred embodiments described above in relation to the chemical pretreatment method of the present invention, the substrate obtainable therefrom, the composition AC of the present invention, the concentrate, the method of use of the present invention, and the coating method of the present invention, as well as these preferred embodiments, are also preferred embodiments of the coating substrate of the present invention.

[0124] method 1. Measurement of free fluoride content The free fluoride content is determined by a fluoride ion selective electrode. The electrode is calibrated using at least three standard solutions with known fluoride concentrations. A calibration curve is constructed through the calibration process. This curve is then used to determine the fluoride content.

[0125] 2. ICP-OES The content of specific elements such as zirconium, titanium, and hafnium in the sample to be analyzed is determined using inductively coupled plasma atomic 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 field, and the light emitted by the electronic transitions is visualized as spectral lines of the corresponding wavelengths and analyzed using an optical system. A linear relationship exists between the intensity of the emitted light and the concentration of the target element. Calibration measurements are performed using known elemental standards (reference standards) according to the sample to be analyzed before the procedure. These calibrations can be used to determine the concentrations of unknown solutions, such as the concentrations of titanium, zirconium, and hafnium.

[0126] 3. Coating mass XRF (X-ray fluorescence analysis) is used to determine the coating mass (mg / m³) of specific (trace) elements such as Ti, Zr, and / or Si in layers such as chemical layers obtained by application. 2 It is used to measure ).

[0127] 4. VDA621-415 Corrosion Test VDA 621-415 (predecessor to VDA 233-102) is a periodic corrosion test with a weekly cycle for evaluating the corrosion resistance of a sample. The sample is scratched across its entire surface in a longitudinal direction. This test is applied to steel substrates. The weekly cycle consists of: 1) salt spray phase (5% NaCl salt spray at 35°C for 24 hours), 2) first condensate climate phase (96 hours in a warm and humid environment at 40°C and 85% relative humidity), and 3) second condensate climate phase (48 hours in a normal temperature environment, i.e., 25°C and 50% relative humidity). The total duration of the test is 10 weeks. After that, the test was conducted in accordance with DIN EN ISO 4628-8, and the overall average value of erosion (undermine; creep) was measured. Furthermore, chipping resistance after 10 weeks was also determined according to Method C of DIN EN ISO 20567-1.

[0128] 5. Copper-catalyzed acetate spray (CASS) mist test according to DIN EN ISO 9227 The copper-catalyzed acetic acid salt spray test is used to evaluate the corrosion resistance of coatings on substrates and is applicable to aluminum and / or aluminum alloys. The sample is scratched all over in parallel longitudinal lines. According to DIN EN ISO 9227 (07-2017), the analyte sample was placed in a chamber, and a 5% saline solution mixed with acetic acid and copper chloride was continuously sprayed within the chamber at 50°C for 504 hours while controlling the pH. The spray mist adhered to the analyte sample, covering it with a corrosive film of saline solution. During the CASS mist test, the substrate corroded along the scratch lines, so the level of erosion (undermine; creep) of the sample was investigated according to DIN EN ISO 4628-8 (March 2013).

[0129] 6. Adhesion Test 1 The substrate was subjected to a wet test (CH: constant high humidity condensation atmosphere) for 240 hours in accordance with DIN EN ISO 2409:2020-12, and then a cross-hatch adhesion test (cross-cut test) was performed according to DIN EN ISO 6270-2:2018-04.

[0130] 7. Boiling test The adhesion of coated panels in dry and wet conditions is measured and compared using boiling and cross-cut tests. The cross-cut test, which measures dry adhesion, is performed according to DIN EN ISO 2409:2020-12 before the boiling test. The panel is then boiled in deionized water at 100°C (212°F) for 2 hours. After 2 hours, the panel is stored at room temperature under experimental conditions for 1 hour. Wet adhesion is then measured by a cross-cut test according to DIN EN ISO 2409:2020-12. In both cases, adhesion is determined by pulling the coating from the cross-cut area using tape.

[0131] 8. Adhesion Test 2 Adhesion Test 2 measures the adhesion of the coated panels in both dry and wet conditions, and these are compared using the GMW 14704 test and the cross-cut test. First, a cross-cut test is performed to measure the dry adhesion strength according to DIN EN ISO 2409:2020-12. Then, the panels are immersed in deionized water at 62-63°C for 48 hours. After that, the panels are stored in a test room at room temperature for 1 hour. Next, a cross-cut test is performed to measure the wet adhesion strength according to DIN EN ISO 2409:2020-12. In both cases, the adhesion is determined by pulling the coating film on the cross-hatch using tape. [Examples]

[0132] The following embodiments further illustrate the present invention, but do not limit its scope.

[0133] 1. Chemical pretreatment composition 1.1 Chemical pretreatment composition CPC1 For the preparation of CPC1, the commercially available Gardo® TP 9906 was used as a precursor. This is an acidic aqueous composition containing a fluoride anion and a zirconium cation. The precursor was added to a 100 L batch, and a chemical pretreatment bath was prepared so that the zirconium cation concentration, calculated as metal, was 100 mg / L. Next, 30 mg / L of the commercially available organic silane-containing product Oxsilan® 9810 / 3, calculated as silicate, was added to the bath. Then, 3090 g / mol of M WA polylysine homopolymer PL1 was added to obtain a polymer concentration of 20 mg / L. PL1 was synthesized by the method described in WO 2022 / 136613 A1 and used in this form without further processing. The preparation of PL1 was carried out according to the procedure for polylysine-5 described in Table 1 of WO 2022 / 136613 A1, except that distillation was continued for a certain period of time after reaching the target pressure, compared to polylysine-5. Furthermore, 10 mg / L of copper cations, calculated as metal, was added to the bath. The bath temperature was then adjusted to 30°C. The pH value and free fluoride content of the obtained bath were adjusted to a pH value of 4.8 and a free fluoride anion concentration in the range of 30-40 mg / L, calculated as fluorine, by adding a diluted sodium bicarbonate solution. Before use in chemical pretreatment of the substrate, the bath was aged for at least 12 hours to obtain chemical equilibrium.

[0134] 1.2 Chemical pretreatment composition CPC2 CPC2 was prepared in the same manner as CPC1, but with the difference being that PL1 was added to achieve a polymer concentration of 200 mg / L.

[0135] 1.3 Chemical pretreatment composition CPC3 CPC3 was prepared in the same manner as CPC2, except that Oxsilan® 9810 / 3 was not used in the preparation of the bath.

[0136] 1.4 Chemical pretreatment composition CPC4 CPC4 was prepared in the same manner as CPC3, but with the difference being that PL1 was added to achieve a polymer concentration of 500 mg / L.

[0137] 1.5 Comparative pretreatment composition REF1 Furthermore, a comparative chemical pretreatment composition REF1 was used. This was prepared in the same manner as CPC1 as described above, but it did not contain the polylysine homopolymer PL1.

[0138] 1.6 Comparative pretreatment composition REF2 Furthermore, a comparative chemical pretreatment composition REF1 was used. This was prepared in the same manner as CPC3, as described above, but it did not contain the polylysine homopolymer PL1.

[0139] 1.7 Chemical pretreatment composition CPC5 For the preparation of CPC5, the commercially available Gardobond® X 4548 was used as a precursor. This is an acidic aqueous composition containing a fluoride anion and a zirconium cation. This precursor was added to a 50 L batch to prepare a chemical pretreatment bath with a zirconium cation concentration of 35 mg / L, calculated as a metal. Subsequently, a mixture of the nonionic surfactant Propetal® 120 and deionized water was added to a 4 g / L bath. After that, 3700 g / mol M was added. W A polylysine homopolymer PL2 was added to obtain a polymer concentration of 400 mg / L. PL2 was synthesized by the method described in WO 2022 / 136613 A1 and used in this form without further processing. The preparation of PL2 was carried out according to the procedure for polylysine-6 ​​described in Table 1 of WO 2022 / 136613 A1, except that after reaching the target pressure, distillation was continued for a certain period of time compared to polylysine-6. The bath temperature was then adjusted to 30°C. The pH value and free fluoride content of the obtained bath were adjusted to a pH value of 5.4 and a free fluoride anion concentration in the range of 20-25 mg / L, calculated as fluorine, by adding a diluted sodium bicarbonate solution.

[0140] 2. Pretreatment including chemical pretreatment methods 2.1 Three types of substrates were used: hot-dip galvanized steel sheet substrate (HDG substrate; S1), cold-rolled steel sheet substrate (CRS substrate; S2), and aluminum alloy substrate (AA6014S substrate; S3). Each substrate was washed at 60°C for approximately 3 minutes using a commercially available phosphate-free alkaline cleaning agent (pH value approximately 10.8). After that, a spray rinse with tap water was performed, followed by a spray rinse with deionized water (30 seconds each, at room temperature).

[0141] Next, a contact process was performed. The entire surface of each substrate was brought into contact with one of the chemical pretreatment compositions described in item 1 above by immersion at 30°C for 3 minutes, thereby forming a chemical conversion film on each substrate surface. In the control example, the contact process with the chemical pretreatment composition was omitted.

[0142] After the contact process, the substrate was spray-rinsed with tap water, followed by spray-rinsing with deionized water (30 seconds each at room temperature). After the rinsing process, a drying process was carried out by hot-air drying in an oven at an air temperature of 120°C for 8 minutes. Finally, a commercially available electrodeposition (ED) coating material (Cathoguard® 800) was applied to the chemical conversion coating surface of the substrate and baked at 175°C for 25 minutes. The dry layer thickness of the ED coating was in the range of 20 μm to 25 μm.

[0143] 2.2 Four types of substrates were used, namely S1 to S3 as described in Section 2.1, and boron steel as substrate S4. Each substrate was cleaned by spraying with the aforementioned composition CPC5. In run a), spraying was performed for 120 seconds at a spray pressure of 1 to 2 bar at 45°C. In alternative run b), spraying was performed for 180 seconds at a spray pressure of 1 to 2 bar at 30°C. In both cases, spray rinsing with tap water was followed by spray rinsing with deionized water (30 seconds each, at room temperature).

[0144] Subsequently, a contact process was carried out. The entire surface of each substrate was immersed in the aforementioned chemical pretreatment composition CPC5 at 30°C for 3 minutes to form a chemical conversion film on the surface of each substrate.

[0145] Following the contact process, the surface was spray-rinsed with tap water, followed by spray-rinsing with deionized water (30 seconds each at room temperature). After the washing process, a drying process was carried out by hot-air drying in an oven at an air temperature of 120°C for 8 minutes. Finally, one of three powder coatings, namely a commercially available polyester powder coating (Interpon® A2201 from AkzoNobel), another commercially available polyester powder coating (RAL 7035 Light Gray Texture from PPG), or a mixed epoxy and polyester powder coating (Interpon® 700 from AkzoNobel), was applied to the surface of the conversion coating.

[0146] 3. Investigation of the properties of chemically pre-treated substrates 3.1 The substrates obtained after carrying out the method described in item 2.1 were investigated according to the method described in the "Methods" section. The results are shown in Tables 1.1 and 1.2.

[0147] [Table 1]

[0148] [Table 2]

[0149] 3.2 The substrates obtained after carrying out the method described in item 2.2 were examined according to the method described in the "Methods" section. The results are shown in Tables 1.3, 1.4, and 1.5.

[0150] [Table 3]

[0151] [Table 4]

[0152] [Table 5]

Claims

1. A method for chemically pre-treating at least one metal surface of at least one substrate, comprising at least step 1), and optionally one or more of steps 2) and 3), i.e. 1) A step of bringing at least one metal surface of the at least one substrate into contact with an aqueous acidic composition AC suitable for forming a coating film on the surface in at least a portion of the surface, The aqueous acidic composition AC comprises, in addition to water, at least two different components a1) and a2), i.e., The constituent component a1) is at least one of zirconium, titanium, and hafnium cation, Component a2) preferably includes at least one lysine homopolymer and / or copolymer having an amide bond, Processes including, 2) Optionally, rinse the coating film obtained after step 1) at least once with at least one aqueous rinsing composition ARC different from the aqueous acidic composition AC, and 3) Optionally, a step of curing or drying the optionally rinsed coating film obtained after step 1) or 2) to obtain a cured or dried coating layer. Methods that include...

2. The method according to claim 1, wherein the at least one lysine homopolymer and / or lysine copolymer is present in composition AC in an amount ranging from 1 to 500,000 mg / L, more preferably 2 to 300,000 mg / L, even more preferably 3 to 200,000 mg / L, even more preferably 4 to 100,000 mg / L, even more preferably 5 to 50,000 mg / L, even more preferably 6 to 20,000 mg / L, even more preferably 7 to 15,000 mg / L, even more preferably 7.5 to 10,000 mg / L, even more preferably 8 to 5,000 mg / L, even more preferably 9 to 2,500 mg / L or 2,000 mg / L, even more preferably 10 to 1,000 mg / L, and most preferably 15 or 20 to 500 mg / L.

3. The method according to claim 1 or 2, wherein the at least one lysine homopolymer and / or lysine copolymer, preferably the lysine homopolymer, present as component a2) in composition AC has a mass-average molecular weight in the range of 500 to 300,000 g / mol or 20,000 g / mol, more preferably 750 to 200,000 g / mol or 15,000 g / mol, even more preferably 1,000 to 100,000 g / mol or 10,000 g / mol, even more preferably 1,500 to 75,000 g / mol or 7,500 g / mol, and even more preferably 2,000 to 50,000 g / mol or 5,000 g / mol.

4. The method according to claim 1 or 2, wherein the at least one lysine homopolymer and / or copolymer, preferably the lysine homopolymer, has an amide bond formed by the reaction of a carboxyl group of one lysine monomer with an amino group of another lysine monomer, the amino group of the other lysine monomer is preferably bonded to its ε-carbon atom, preferably the formed lysine homopolymer is an L-lysine homopolymer, more preferably an ε-poly-L-lysine homopolymer, and / or the at least one lysine homopolymer and / or copolymer, preferably the lysine homopolymer, is a polymer containing at least 10, up to 100, more preferably at least 15, up to 75, even more preferably at least 20, up to 50, even more preferably more than 20, for example at least 25, up to 40, for example up to 30 lysine units, the lysine units are preferably L-lysine units, the at least one lysine homopolymer and / or copolymer is preferably a cationic charged polymer, and / or the at least one lysine homopolymer and / or copolymer has an amino group.

5. The method according to claim 1 or 2, wherein the aqueous composition AC contains at least one of zirconium, titanium, and hafnium cations, calculated as metal in each case, in an amount ranging from 1 or 5 to 4000 mg / L, more preferably 7.5 to 2000 mg / L, even more preferably 10 to 1500 mg / L, even more preferably 12.5 to 1000 mg / L, even more preferably 15 to 750 mg / L, and even more preferably 20 to 500 mg / L.

6. The method according to claim 1 or 2, wherein the aqueous composition AC has a pH value in the range of 0.1 to less than 7.0, preferably 0.5 to 6.5, more preferably 1.0 to 6.0, even more preferably 1.5 or 2.0 to 5.5, even more preferably 2.5 or 3.0 to 5.25, and most preferably 3.5 or 4.0 to 5.

0.

7. The method according to claim 1 or 2, wherein the aqueous composition AC further contains, as component a3), a fluoride anion containing a complex fluoride anion, in an amount calculated as fluorine in each case, preferably 5 or 10 to 2000 mg / L, more preferably 15 to 1500 mg / L, even more preferably 20 to 1000 mg / L, and even more preferably 25 to 500 or 200 mg / L.

8. In aqueous composition AC, the fluoride anion present as a complex fluoride anion, which is coordinated to at least one of the zirconium, titanium, and hafnium cations present as component a1) in the composition, is H in each case. ２ MF ６ The method according to claim 7, wherein the amount is calculated as (wherein M is Zr, Ti and / or Hf) and more preferably ranges from 1 or 50 mg / L to 4000 mg / L, even more preferably from 10 or 100 mg / L to 2000 or 1500 mg / L, and even more preferably from 50 or 100 mg / L to 500 or 250 mg / L.

9. The aqueous composition AC further, As component a4), at least one organosilane and / or its hydrolysate and / or condensation product, calculated in each case as elemental silicon, preferably in the range of 0 or 5 to 20,000 or 15,000 mg / L, more preferably 0 or 10 to 10,000 or 5,000 mg / L, even more preferably 0 or 15 to 1,000 or 500 mg / L, and / or As component a5), zinc cations are used, calculated as a metal in each case, preferably in an amount ranging from 0 or 5 to 5000 mg / L, more preferably from 0 or 10 to 2500 mg / L, and / or As component a6), copper cations are calculated as a metal in each case, preferably in an amount ranging from 0 or 1 to 1000 mg / L, more preferably from 0 or 1 to 500 mg / L, even more preferably from 0 or 2 to 100 mg / L, and even more preferably from 0 or 2.5 to 50 mg / L. The method according to claim 1 or 2.

10. Step 3) is performed, and the cured or dried coating layer obtained after step 3) preferably has a dry film thickness of less than 0.5 μm, and / or the cured or dried coating layer obtained after step 3) preferably has a film thickness of 0.5 to 500 mg / m². ２ More preferably 1 to 400 mg / m² ２ More preferably, 2 to 350 mg / m² ２ The method according to claim 1 or 2, wherein the coating mass is determined in each case to be a trace element such as Ti, Zr, and / or Si by XRF measurement, within the range of .

11. The method according to claim 1 or 2, further comprising at least one cleaning step performed prior to step 1), wherein at least one metal surface of the at least one substrate is in contact with at least one cleaning composition in at least a portion thereof, the cleaning composition being different from or the same as the aqueous acidic composition AC used in step 1), and the cleaning composition preferably comprises at least one surfactant.

12. The method according to claim 1 or 2, wherein at least one metal surface of the at least one substrate is composed in at least part of at least one of steel, steel alloy, aluminum, aluminum alloy, zinc, zinc-magnesium alloy, and mixtures thereof, preferably in at least part of at least one of steel and steel alloy.

13. An aqueous acidic composition AC as defined in claim 1, comprising, in addition to water, at least one of zirconium, titanium, and hafnium cations as component a1) and at least one lysine homopolymer and / or copolymer having an amide bond as component a2), or a concentrate of the aqueous acidic composition AC which can be obtained by dilution with water and, if necessary, further pH adjustment.

14. A method for using at least one lysine homopolymer and / or copolymer as defined in claim 1 or 2, incorporated into an aqueous composition AC, preferably the aqueous acidic composition AC according to claim 13, to provide or improve corrosion resistance to a metal surface of a substrate and / or to provide or improve adhesion to one or more further coating layers present on the metal surface of a substrate.

15. A method for coating at least one chemically pretreated metal surface of at least one substrate, wherein the chemical pretreatment of at least one metal surface is carried out according to the method of claim 1 or using the aqueous acidic composition AC described in claim 13, at least step 4), i.e. 4) Applying at least one coating material composition comprising at least one film-forming polymer and / or resin to a film that has been optionally rinsed after step 1) or 2) as defined in claim 1, or to a dried or cured film, preferably a dried film, which can be obtained by drying or curing the film obtained from any step 3) as defined in claim 1. Methods that further include the above.

16. A substrate that is a chemically pretreated substrate obtainable by the method of claim 1, or a coated substrate obtainable by the method of claim 15.

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