WO2023110154A1 - Procédé de production d'un matériau revêtu hautement résistant à l'abrasion comportant une couche de conversion sur un substrat en aluminium, en particulier en forme de bande - Google Patents

Procédé de production d'un matériau revêtu hautement résistant à l'abrasion comportant une couche de conversion sur un substrat en aluminium, en particulier en forme de bande Download PDF

Info

Publication number
WO2023110154A1
WO2023110154A1 PCT/EP2022/051493 EP2022051493W WO2023110154A1 WO 2023110154 A1 WO2023110154 A1 WO 2023110154A1 EP 2022051493 W EP2022051493 W EP 2022051493W WO 2023110154 A1 WO2023110154 A1 WO 2023110154A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
aluminum
intermediate layer
carrier
paint
Prior art date
Application number
PCT/EP2022/051493
Other languages
German (de)
English (en)
Inventor
Carmen WÜLFING
Thorsten GÖSCHEL
Ralf Hillebrand
Thomas Wilke
Original Assignee
Alanod Gmbh & Co. Kg
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alanod Gmbh & Co. Kg filed Critical Alanod Gmbh & Co. Kg
Publication of WO2023110154A1 publication Critical patent/WO2023110154A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/06—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used
    • C25D11/08—Anodisation of aluminium or alloys based thereon characterised by the electrolytes used containing inorganic acids
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/16—Pretreatment, e.g. desmutting
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
    • C25D11/02—Anodisation
    • C25D11/04—Anodisation of aluminium or alloys based thereon
    • C25D11/18—After-treatment, e.g. pore-sealing
    • C25D11/24—Chemical after-treatment

Definitions

  • the present invention relates to a method for producing a highly abrasion-resistant material with an aluminum carrier, in particular in the form of a strip, with an intermediate layer produced on the carrier by conversion and containing anodically oxidized aluminum oxide, and with a protective surface layer made of an organic paint, comprising the following steps: a ) providing the carrier material, b) cleaning the carrier material, c) superficial conversion of the carrier to produce the intermediate layer, d) applying the organic paint to the intermediate layer to produce the surface protective layer and e) curing the surface protective layer.
  • the invention relates to a material produced in this way.
  • a material similar to the type mentioned at the outset is known from WO 00/29784 A1. It is a composite material with a reflection-enhancing, optically effective multi-layer system, which is also referred to as a functional coating. At least one pretreatment layer can be arranged as an intermediate layer between the carrier and the functional coating Conversion layer can be. It is stated that it is generally known that strips made of bright materials, e.g. B. from ultra-pure aluminum based on aluminum with a purity of 99.8% and greater, such as. B. 99.9%, or from AIMg alloys to produce, as well as to produce rolling surfaces with diffuse or directed light reflection. However, the use of ultra-pure aluminum is very expensive.
  • EP 1 493498 A1 describes a coating of a metal with a lacquer that does not require a primer system.
  • a composite material is to be produced which has a core, a metal layer arranged on the core and a protective lacquer layer arranged on the metal layer.
  • the method comprises the following steps: a) providing a metallic carrier material, b) cleaning the carrier material, c) applying a lacquer to the carrier material to produce the protective lacquer layer and d) allowing it to cure at least partially the protective lacquer layer.
  • the carrier material on the paint application side is subjected to a conversion treatment after the cleaning treatment, and a paint is used which contains substances that can be polymerized in a free-radical and/or ionic manner, in which case this paint applied to the carrier material undergoes a free-radical and/or ionic polymerization for at least is subjected to partial curing thereof.
  • the patent application is aimed at a so-called no-rinse process, according to which a zirconium and/or titanium layer is applied to the paint application side of the metallic substrate with the conversion treatment of the metal, so that post-rinsing can be omitted.
  • aluminum is mentioned as a carrier material, which is subjected to a conversion treatment before the paint is applied until a layer thickness of, for example, 1 mg/m 2 to 40 mg/m 2 , based on zirconium, results.
  • DE 100 14 035 A1 discloses a multi-layer coating with at least two layers, the first layer being a conversion layer on a metal and having pores, and the second layer on the conversion layer being obtainable by applying a solution containing at least an alkoxysilane compound and a dye soluble in a polar solvent, onto the conversion layer, followed by subsequent polymerization and/or crosslinking of the alkoxysilane compound.
  • conversion layers on metals are widespread, the term "conversion layer” meaning a layer that is not applied to a metallic surface, but by chemical conversion (conversion) of this metallic surface and various components of a aqueous passivation electrolyte is formed.
  • the conversion layer has different functions depending on the type of metal and the method used to produce the conversion layer.
  • the industrially best-known methods for producing conversion layers are the electrolytic formation of oxide layers
  • DE 100 14 035 A1 states that the pore size of an aluminum oxide layer produced by anodic oxidation is known to be between 50 nm and 100 nm. Choosing an alkoxysilane compound as the compound to be polymerized and/or crosslinked ensures that the coloring layer on the conversion layer is bonded to the surface of the conversion layer as a result of chemisorption via Si-O bonds, but also via chemisorption inside the pores.
  • a coating in the broadest sense is a liquid or powder coating material that is applied thinly to objects and through chemical or physical processes - for example by evaporating a solvent - to form a continuous coating , solid film is built up, the described dissolved alkoxysilane compound meets these criteria.
  • a compound capable of forming a titanium complex is added to the solution to be applied to the conversion layer.
  • the term "compound capable of forming a titanium complex” denotes compounds which form bridged TiO2-SiO2 systems with the alkoxysilane compound and the conversion layer via complex bonding. This known method is also regarded as generic.
  • primer layers under the paint.
  • These primers also have the disadvantage of causing additional material and process costs.
  • problems can arise with the primers because insufficient blocking resistance or unintentional activation of the primer can lead to undesired adhesion to plant components or to the next layer in a coil.
  • such a primer layer can have an unfavorable influence on the leveling of the top coat, insofar as it can lead to non-uniform painting and adversely affect the transparency of the coating.
  • the pot life of the chemicals used disadvantageously limits processing flexibility.
  • the object of the present invention is to provide a method of the type described at the outset, with which the disadvantages described above can be avoided, in particular in that it is not restricted to the use of special lacquers, does not require doping of the conversion layer or the application of primers, and leads to a product according to the invention which, with high transparency of the paint and optionally high directed or diffuse reflectivity, is distinguished by significantly improved adhesion of the paint to the substrate.
  • paint systems which are preferably quick-drying and hardened by free radicals under the influence of radiation, in particular under UV radiation.
  • the intermediate layer produced by conversion consists of aluminum oxide, which is produced by anodic oxidation in an electrolyte bath containing phosphoric acid in such a way that it has a branched, open pore structure.
  • the oxide layer has micropores immediately after production and usually forms a columnar structure, which resembles a honeycomb when viewed from above, which has a single pore in the middle of a honeycomb cell, which in turn is closed at the bottom by a likewise aluminum oxide barrier layer.
  • the pores can subsequently be closed by forming aluminum hydroxide or aluminum oxide hydrate by means of a final compression or sealing with steam, in order to produce a compact layer with closed pores.
  • Such an anodically produced oxide layer has a high resistance to corrosion and wear.
  • Industrially used, anodically oxidized products made of aluminum and wrought aluminum alloys are subject to the technical delivery conditions in accordance with the DIN 17611:2011-11 standard.
  • aluminum products arise, in particular aluminum rolled products, which can be made of pure aluminum or of different aluminum alloys with a low iron and copper content, the 1xxx, 3xxx and 5xxx series according to the standard DIN EN 573-3:2009-08 are preferred.
  • support made of aluminum is therefore understood in a broad sense.
  • aluminized metal parts or sheets or material clad with aluminum e.g. B. roll-clad Al / steel / Al composite material can be used in the process according to the invention as support materials.
  • a phosphoric acid-containing electrolyte bath is understood to mean those bath compositions which contain phosphoric acid in a mass fraction of at least 15% and at most 45%, in particular in a mass fraction in the range from 20% to 30%.
  • other components in the bath can also include other acids, e.g. As sulfuric acid or organic acids, and their salts may be included.
  • the substrates are subjected to the anodizing process according to the invention, in which they are first passed through an aqueous phosphoric acid bath.
  • the phosphoric acid concentration, the temperature, the type of current, e.g. B. constant, increasing or decreasing direct current or a pulsating operation, the electric current density, the voltage and the duration of the treatment are set product-specifically in such a way that a branched open pore structure is formed.
  • This structure which can also be described as dendritic or finger-like, then allows easy penetration of the paint into the conversion layer, even with comparatively higher viscosity and surface tension and in the absence of additional absorption-enhancing substances. It is also not necessary to use very thin, aqueous or organic solvents, as are known from the prior art.
  • the layer thicknesses of the anodized conversion layer can be in a range from 20 nm to 3 ⁇ m, preferably in a range from 70 nm to 0.7 ⁇ m.
  • the pore diameters can be in the range from 10 nm to 50 nm, preferably in the range from 20 nm to 35 nm. According to the usual classification: pore diameter ⁇ 2 nm - micropores, 2 nm to 50 nm - mesopores and > 50 nm - macropores, it is therefore in particular mesopores.
  • the gas adsorption technique or the mercury intrusion technique can be used to measure the pore size, the results of which differ only insignificantly from one another.
  • isotherms (usually N2, Ar, or CO2) are recorded from low pressures (ca. 0.00001 Torr minimum) to saturation pressure (ca. 760 Torr).
  • the pressure range depends on the size range of the pores to be measured.
  • Isotherms of microporous materials are measured over a pressure range of about 0.00001 torr to 0.1 torr
  • isotherms of mesoporous materials are typically measured over a pressure range of 1 torr to about 760 torr.
  • gas adsorption can be applied to pores ranging from 3.5 angstroms to about 4000 angstroms in diameter.
  • the pore size distribution can also be determined using a number of different methods (theories or models).
  • the available mesopore methods include, for example, the method according to Barrett, Joyner and Halenda (BJH method) and density functional theory (DFT).
  • mercury intrusion porosimetry With mercury intrusion porosimetry, the sample is placed in a special sample cup (penetrometer) and coated with mercury. Mercury hardly wets any material and does not penetrate pores unless under pressure. The pressure under which mercury enters a pore is inversely proportional to the size of the pore opening. Pressures ranging from 0.2 to 60,000 psi allow measurement of pores from 30 angstroms to 900 microns in diameter. The mercury to penetrate pores in the sample material comes from a capillary tube container connected to the sample cup. The cumulative volume emptied after each pressure change is determined by measuring the change in capacity of the tube. The intrusion volume is recorded with the appropriate pressure or pore size.
  • a wet-on-wet application of the paint to form the protective layer after anodizing can in principle be practiced, but it can also be applied to a dried aluminum oxide surface that has been subjected to intermediate drying, especially if the paint and water used for the coating are not are soluble in one another or the carrier provided with the conversion layer is produced as an intermediate product spatially separate from the location of the coating.
  • organic paints that can be used with preference for producing the protective surface layer are those that can be cured with electromagnetic radiation, in particular with UV light.
  • unsaturated acrylates such as in particular epoxy acrylates, polyester acrylates, polyether acrylates, urethane acrylates and acrylic acrylates, and also unsaturated polyesters or also acrylic-modified polysiloxanes (silicone acrylates). Coating mixtures with these components can also be used.
  • the lacquer of the protective surface layer can be cured by means of electromagnetic radiation, in particular by means of UV radiation, electron beams or particle beams.
  • a technology can be used in the curing that comprises several curing stages, such as pre-gelation, subsequent excimer curing and UV final curing. Polymerization and crosslinking take place during curing.
  • the polymerization preferably proceeds as a free radical, although a cationic polymerization can also be practiced.
  • any solvents present in the paint such as one or more alcohols, ketones and/or acetates, can be expelled by heat, for example in a drying section.
  • FIG. 1a shows an enlarged basic sectional view through an embodiment of a material according to the invention and produced in a method according to the invention, the layer thicknesses contained therein being shown purely schematically and not to scale,
  • FIG. 1b shows a schematic sectional view of an embodiment of an anodically oxidized carrier material produced according to the invention
  • table 3 a table (table 1) for the surface quality of anodically oxidized products made of aluminum and wrought aluminum alloys in accordance with the standard DIN 17611:2011-11, 4a and 4b exemplary electron micrographs of an anodically oxidized carrier material produced according to the invention,
  • Fig. 5 a “microelectrolyte model” for the adhesion between aluminum and polymer molecules carrying COOH groups
  • FIG. 6 shows a scheme for the multi-stage curing of the surface protective layer of a material according to the invention and produced in a method according to the invention after thermal drying
  • a material M produced according to the invention has a carrier 1 made of aluminum, in particular in the form of a strip, i.e. designed as a coil, with the thickness Di, an anodically oxidized aluminum oxide produced by conversion and located on one side of the carrier 1 containing intermediate layer 2 with the thickness D2 and applied to the intermediate layer 2 highly abrasion-resistant protective surface layer 3 made of an organic paint with the thickness D3.
  • the carrier 1 can have a thickness Di in the range from 0.05 mm to 20.0 mm, preferably in the range from 0.5 mm to 8.0 mm, particularly preferably from 0.7 mm to 1.1 mm.
  • the inventive method for producing the material M comprises the following steps: a) providing the material of the carrier 1, b) cleaning the material of the carrier 1, c) superficial conversion of the carrier 1 to produce the intermediate layer 2, d) application of the organic paint the intermediate layer 2 for producing the surface protective layer 3 and e) curing the surface protective layer 3.
  • the method according to the invention is characterized in that the intermediate layer 2 produced by conversion consists of aluminum oxide, which is produced in this way by anodic oxidation in an electrolyte bath containing phosphoric acid is that it has a branched open pore structure VOP, as illustrated by way of example in FIG. 1a and in particular also in FIG. 1b.
  • the structure of the intermediate layer 2 differs significantly from an anodized layer Al2O3 produced conventionally, in particular with a sulfuric acid electrolyte, as is shown schematically in FIGS. 2a and 2b.
  • These pores P which are arranged essentially parallel and perpendicular to the surface of the aluminum support, are each closed on the underside by a barrier layer S made of aluminum oxide and, as shown in FIG Aluminum hydroxide or aluminum oxide hydrate be sealed. It is also the case that the upper part of the layer already swells during the anodization due to the increasing molecular weight of the transition from aluminum to aluminum oxide, and that the pores P can be closed simply by the increase in volume that occurs as a result.
  • the known anodized material thus differs significantly from the material M according to the invention with its intermediate layer 2, as indicated schematically in FIGS. 1a and 1b and shown in electron micrographs in FIGS. 4a and 4b.
  • the pores—at least in the upper part of the anodizing layer—in the branched open pore structure VOP are preferably Y-shaped, i.e. each dendritic—like a tree (Greek: dendros)—with a trunk at the bottom and many branches at the top.
  • the presence of the carrier-side barrier layer S represents a common feature.
  • FIG. especially when the anodizing process is multi-stage, e.g. B.
  • Typical of the invention is the fibrous or finger-like interface oxide, which brings about two advantages in particular. Firstly, it leads to an increase in the interface with the surface protection layer 3, and secondly, the fingers can dip into the paint and thus improve adhesion on the one hand and act as a crack stopper on the other.
  • the height of the branched open pore structure VOP according to FIG. 1b corresponds to approximately 25% of the total layer thickness D2 of the ANOX layer and there is no preferred direction.
  • the total layer thickness D2 is 400 nm, for example, with the intermediate layer 2 produced by conversion and consisting of aluminum oxide generally having a thickness D2 in the range from 30 nm to 1.2 ⁇ m, preferably in the range from 100 nm to 1.0 ⁇ m. may have.
  • the porous anodized surface according to the invention is a heterogeneous surface
  • the equation can be used to try to explain it, whereby it makes it clear that low-viscosity paints penetrate more easily into the pores of this heterogeneous surface than high-viscosity ones.
  • Table 1 shown in FIG. 3 relates to the surface quality of anodically oxidized products made of aluminum and wrought aluminum alloys in accordance with the standard DIN 17611:2011-11 with the qualities E0 to E3 and E6 to E8. Table 1 is listed here in particular in order to show what the process steps provided according to the invention a) providing the material of the carrier 1 and b) cleaning the material of the carrier 1 can consist of.
  • Table 1 does not refer to the material M according to the invention as such, since this still has the additional lacquer layer 3 on its surface.
  • the statement “preferably indoors” in column 4 for quality E3 should advantageously be reworded to “both for indoor use and equally for outdoor use” due to the significantly higher corrosion and abrasion resistance of material M according to the invention.
  • a universal primer is provided for the paint, in particular for free-radically curing paint systems, which means that the material produced according to the invention primarily differs from the prior art through significantly improved adhesion of the paint of the surface protection layer 3 on the Substrate (carrier 1 and intermediate layer 2) is distinguished.
  • the two FIGS. 4a and 4b show this primer in the form of electron micrographs of an anodically oxidized carrier material 1/2 produced according to the invention over a length of 4 mm and magnified 5000 times, with FIG. 4a showing a cross section and FIG. 4b showing a top view.
  • the light layer on the intermediate layer 2 that is superficially visible in FIG.
  • deformation represents a particularly strong stress
  • the surface protection layer 3 - which is as hard as possible for the purpose of high abrasion resistance and thus also tends to be brittle - tends to form cracks, on which shear stresses can then attack particularly well, which in the prior art leads to delamination effects leads.
  • the cracks appear in places where the adhesion is reduced, so that intrinsic stresses also arise, which together with the stresses occurring due to the deformation lead locally to such great forces that the breaking stress is exceeded. Starting from these breaking points, the delamination then continues.
  • the lacquer layer 3 is instead uniformly supported by the substrate and there are no local force peaks and consequently no delamination either.
  • a “microelectrolyte” forms between the aluminum of the carrier 1 and an acidic paint polymer, as can be explained with reference to FIG. 5, which shows a “ Microelectrolyte model” for the adhesion between aluminum and polymer molecules bearing COOH groups. Radically hardening polymers that contain acid groups can be combined with aluminum or aluminum oxide in an H3PO4 acid bath that is still present - especially when the paint is applied wet-on-wet - and that can be understood as a "macroelectrolyte" (in Fig 5 referred to above) form a "microelectrolyte".
  • the Al 3+ cations contained in the substrate made of support 1 and intermediate layer 2 are able, according to the voltage series, to displace H + ions from non-oxidizing acids. This means that the Al 3+ cations with the COOH groups of the acidic polymer—in addition to hydrogen bridge bonds occurring as secondary valences—also enter into ionic relationships with comparatively higher binding energy as main valences, which contribute significantly to the bond strength.
  • the anodizing bath usually contains sulfuric acid, which has a redox potential E° of +0.158 V (see Table 2 below “Comparison of acid redox potentials”).
  • anodizing in phosphoric acid which has a redox potential of -0.276 V and thus forms a much less noble electrolyte, increases the readiness of the Al 3+ ions to displace H + ions from non-oxidizing acids and thus creates an ion relationship with carboxylate Go into groups of the paint binder and consequently form ionic relationships between the substrate and the acidic groups of the polymer.
  • the anodizing of the intermediate layer 2 which is produced on the carrier 1 by electrochemical oxidation, is monolithically connected to the carrier 1, in particular via the barrier layer S formed from the material of the carrier 1, so that it not only adheres excellently, but also as illustrated in Table 1 in FIG. 3, the original aluminum surface is reproduced conformally and, in addition, deformations of the carrier 1 are also carried out.
  • the open-pore surface topography of the VOP produced using phosphoric acid In addition to the higher adhesion caused by increased chemical bonding forces, the anodizing according to the invention also leads to mechanical anchoring between the substrate and the paint.
  • intermediate layer 2 and protective surface layer 3 Another reason for the extraordinarily high bond strength of intermediate layer 2 and protective surface layer 3 according to the invention can be seen in the preferably multi-stage implementation of drying and curing.
  • a dryer unit that is arranged before a UV unit that is finally intended for curing, monomers in the paint can already be present before their Polymerization penetrate into the pore structure of the intermediate layer 2. This is where the firmly adhering connection between the polymer and the anodized aluminum is created as the polymer structure builds up.
  • a substrate was produced by carrying out the above process steps a) to c), which consists of the aluminum support 1 and the anodically located thereon Al2O3 layer produced with the open-pored structure VOP according to the invention.
  • the concentration, temperature, voltage, current type, voltage and duration of the treatment were adjusted product-specifically as follows.
  • Phosphoric acid 200 g/l -300 g/l, d. H. Acid concentration: 20-30% by mass Temperature: 40°C - 55°C Voltage: 25 V - 50 V DC Residence time: 6 s - 60 s Dissolved aluminum: 2-12 g/l
  • the anodizing proceeded according to the known pattern. Since the initially formed Al2O3 barrier layer S initially electrically insulates the anodically connected aluminum carrier 1, the electrical resistance at the anode increases. This also increases the voltage required for the reaction. This means that areas of the oxide layer that are particularly badly attacked by the electrolyte are broken through. Due to the missing or only thin oxide layer at these points, the current density increases there, which leads to local heating. At these warmer points, the oxide layer is increasingly dissolved, so that channel-like depressions are formed in the layer that continues to grow. The channels enable a charge exchange with the electrolyte and are therefore kept open by it.
  • the surrounding oxide layer continues to grow, the channels remain, and a porous structure forms, which, due to the phosphoric acid bath when implementing the regime specifically designed according to the invention, led to a branched, open-pored pore structure VOP, as shown schematically in Fig. 1 and as an example in 4a and 4b.
  • a solvent-based UV coating system was used in the implementation of the above-mentioned process step d).
  • used consisting of an unsaturated aliphatic urethane acrylate combined with a tetrafunctional acrylate monomer. Both substances are characterized by their high transparency, have acid numbers in the range from 1 mg KOH/g to 10 mg KOH/g and differ in their viscosities and reactivities for controlling leveling and flexibility.
  • the paint applied to the intermediate layer 2 to form the surface protective layer 3 should preferably have a viscosity measured according to DIN 53211:1996-10 which, when using a DIN 4 mm cup, results in an outflow time in the range from 10 s to 100 s , preferably from 15 s to 20 s, is writable.
  • a photoinitiator was used in the paint system from the group of a-hydroxy, a-alkoxy or a-amino aryl ketones, acylphosphine oxides, azo compounds and tertiary amines was selected, and which had a high reactivity, good compatibility and a low tendency to yellow.
  • This photoinitiator particularly preferably trimethylbenzoyldiphenylphosphine oxide, initiates the cleavage of the double bonds of the acrylate monomer after decomposition into free radicals caused by UV light and thus triggers a free radical polymerization.
  • Radiation-curable additives that can optionally be used, such as organically modified polysiloxane copolymers, polyethersiloxane copolymers, polyether acrylates and silica nanoparticles, improve flow behavior, flow, substrate wetting, lubricity (so-called slip effect), scratch resistance and foam behavior. All of these raw materials are soluble in solvents such as alcohols, ketones and acetates.
  • the UV coating can be matted with pyrogenic silica or colored with tinting pastes to give an opaque or translucent color (see Fig. 7b).
  • Binders with a very high acid number of 100 mg KOH/g to 400 mg KOH/g can act as adhesion promoters Based acidic mono-, di-, tri- or tetrafunctional acrylates and methacrylates are used.
  • Table 3 reproduces an exemplary paint formulation, formulated taking these facts into account, for achieving a highly mechanically stable quality of the surface protective layer 3 .
  • the UV lacquer formulated in this way had been dispersed with a paddle stirrer or a dissolver of known dimensions and rotational speed until the usual vortices were achieved, it was applied to the intermediate layer 2, specifically by a roller application method.
  • this feed rate v is then the speed-determining step for the overall method.
  • the paint flow caused by the surface tension and viscosity of the wet paint determines the painting and production speed.
  • a gradual technology with a pre-gelation Z-curing of the paint in a pre-curing stage 100, with subsequent intermediate curing 200 using an excimer laser and with final UV final curing 300 could be used, for which reference is also made to Fig. 6 .
  • Excimer lasers are gas lasers that can generate electromagnetic radiation in the ultraviolet wavelength range.
  • the word excimer was formed from the combination of the English term “excited” and the term “dimer” and describes the laser-active medium.
  • a dimer is basically two of the same atoms or molecules.
  • noble gas halides are primarily used today as the laser-active medium. Thus, the correct term is actually exciplex laser (from excited and complex), but this name is rarely used in practice.
  • Fig. 7c Such a folding of the lacquer surface by an excimer laser matting is illustrated by Fig. 7c, while Fig. 7a refers to a high-gloss surface of the surface protective layer 3 characterized by directed reflection and Fig. 7b refers to a surface protective layer 3 produced using matting agents causing diffuse reflection relates.
  • the haptics could also be controlled.
  • This radiation unit 100 ensured that the polymer was pre-gelled in order to form a finer microstructuring during the subsequent excimer irradiation.
  • the dose was chosen so that 40% to 50% of the acrylate double bonds were converted and the paint surface remained liquid but became highly viscous. The final UV final curing then took place as described above.
  • FIGS. 8a to 8c refer to the underlying chemical reactions. They show the mechanism of the radical polymerization of a UV light cleaved benzoyl radical with an acrylate.
  • FIG. 8a shows the starting reaction stimulated by the benzoyl radical.
  • a photoinitiator is first split by UV light at the carbon atom that has the highest oxidation number - the so-called aC atom, which is marked by a thick dot in the figures.
  • the benzoyl radical generated in this way then cleaves the double bond of the acrylate, in this case a propenoate ester, so that an acrylate radical is formed, which in turn can then cleave further acrylate double bonds.
  • Chain growth occurs in a matter of seconds, as shown in FIG. 8b.
  • a polymer forms, through which the paint film 3 is then essentially formed.
  • the reaction assumes an olefinic monomer structure.
  • polyfunctional acrylates not only chains are formed, but a polymer network.
  • the polymer shown on the right in FIG. 8b can still have a radical character—as long as no chain termination has taken place.
  • the required percentage conversion of the acrylate double bonds can be determined using ATR infrared spectroscopy and should ultimately be close to 100%.
  • the paint should therefore have a degree of curing of over 90%, preferably over 95%.
  • a degree of curing of 85% is to be regarded as the minimum not to be undercut.
  • the ATR infrared spectroscopy is a measurement technique for the surface investigation of substances such as e.g. B. paint layers or polymer films and liquid samples such as solvent mixtures. Spectrally dependent intensities of reflected light are measured in the infrared range, from which conclusions can then be drawn about the medium being examined. For this purpose, an unexposed sample (0% curing) and a sample that was exposed to an excess of UV radiation (100% curing) are measured as reference samples for calibration. A simple two-point calibration can be created using the two reference spectra. Since during the polymerization—as FIGS.
  • coatings with a layer thickness of 12 ⁇ m were applied and cured by the method described above to differently pretreated 0.1 mm thick aluminum substrates 1 .
  • the following substrate samples were compared with one another after coating with paint: a. aluminum strip, chemically degreased, b. aluminum strip, thermally degreased, c.
  • Aluminum strip, anodized according to the invention e.
  • a cross-cut with a blade spacing of 1 mm was then carried out using a multi-cutter from Erichsen in accordance with DIN EN ISO 2409:2020-1 with Tesa trigger.
  • the standard specifies a test method for estimating the resistance of a coating to separation from the substrate when a continuous grid is cut into the coating down to the substrate. The property determined by this empirical method depends, among other factors, on the adhesion of the coating to the previous layer or to the substrate. Since the cross-cut test is primarily intended for use in the laboratory, it is also suitable as a field test.
  • the specified procedure can be used either as a yes/no test or, as in the present case, as a six-level classification test. In the case of multi-layer systems, the interlayer adhesion can also be estimated.
  • the test may be carried out on finished objects and/or on test panels specially manufactured for this purpose.
  • UV coating surfaces of different layer thicknesses were produced as a transparent clear coating system on a 0.8 mm thick (Di + D2) phosphoric acid anodized aluminum using the method described above.
  • Ds layer thicknesses
  • the steel tip with a diameter of 0.75 mm of the Erichsen model 318 S hardness tester was used to scratch the surface.
  • the handling of the hardness test rod is very easy.
  • An estimated or already known spring force (F) is set with a slider. The device is then placed vertically with the tip on the test point and a line approx. 5 mm to 10 mm long is drawn at approx. 10 mm/s.
  • the test pin should leave a mark that is just visible. If the spring tension is too high, the trace is clearly visible. If the spring tension is too low, no trace can be seen. If necessary, the test is repeated until a clear result is available.
  • the clamped slide fixes the set force F in Newton.
  • the layer thicknesses D 3 of the respective paint layer 3 were here in the range from 7 ⁇ m to 30 ⁇ m, it being possible in general for this surface protective layer 3 to have a thickness Ds in the range from 0.1 ⁇ m to 100 ⁇ m, preferably in the range from 0. 5 pm to 60 pm, particularly preferably from 3.0 pm to 30 pm, may have. According to the invention, values of up to 3.5 N can be achieved for the force F characterizing the scratch resistance.
  • Table 6 contains under items 1 to 6 in detail the parameters of foiled samples and under items 1.1 to 6.1 in detail the parameters of samples greased instead.
  • the items represent treatment versions, with an aluminum alloy of the 5xxx series being used as the material of the carrier 1.
  • Items 4 and 4.1 were materials M according to the invention.
  • a molded part BT as shown in FIG. 9, was produced by way of example by the deformation/deep-drawing. It was a decorative panel, which is also partially embedded in plastic during assembly.
  • the points with the designations A, C, F, I, J and K are corners.
  • the locations labeled B, D, G, and H are comparatively sharp edges, while the M designation denotes a comparatively blunt edge, i.e., a test location where the area exhibits a small amount of strain caused by compression (rather than tension).
  • the location labeled E is a flow line region.
  • the component was subjected to a 24-hour boiling test, in which the dye Rhodamine B was added to the boiling water.
  • the surface of the component BT showed a magenta-colored discoloration, with cracks and paint delamination being able to be detected by color defects.
  • Table 9 contains the corresponding results.
  • Table 10 Results of the salt spray test NSS after 336h The results in Tables 7, 8 and 10 for positions 1 to 6 also applied, mutatis mutandis, to positions 1.1 to 1.6. The same results were obtained with the greased parts and the foiled parts.
  • sample variants 4 and 4.1 according to the invention showed the best results in all stress tests. In particular, neither cracking nor paint detachment occurred.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Paints Or Removers (AREA)

Abstract

L'invention concerne un procédé de production d'un matériau hautement résistant à l'abrasion comportant un substrat (1), en particulier en forme de bande, constitué d'aluminium, une couche intermédiaire (2) générée sur le substrat (1) par conversion et contenant de l'oxyde d'aluminium anodisé, et une couche de protection de surface (3) constituée d'un revêtement organique, comprenant les étapes suivantes consistant à : utiliser le matériau du substrat (1) ; nettoyer le matériau du substrat (1), la conversion de niveau de surface du substrat (1) pour générer la couche intermédiaire (2) ; appliquer le revêtement organique à la couche intermédiaire (2) pour produire la couche de protection de surface (3) ; et durcir la couche de protection de surface (3). Selon l'invention, la couche intermédiaire (2) créée par conversion est constituée d'oxyde d'aluminium, qui est produit par anodisation dans un bain électrolytique contenant de l'acide phosphorique, de telle sorte qu'il présente une structure à pores ouverts ramifiés (VOP).
PCT/EP2022/051493 2021-12-17 2022-01-24 Procédé de production d'un matériau revêtu hautement résistant à l'abrasion comportant une couche de conversion sur un substrat en aluminium, en particulier en forme de bande WO2023110154A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102021133647.3 2021-12-17
DE102021133647.3A DE102021133647A1 (de) 2021-12-17 2021-12-17 Verfahren zur Herstellung eines hochabriebfesten, lackbeschichteten Materials mit einer Konversionsschicht auf einem insbesondere bandförmigen Aluminiumträger

Publications (1)

Publication Number Publication Date
WO2023110154A1 true WO2023110154A1 (fr) 2023-06-22

Family

ID=80447806

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2022/051493 WO2023110154A1 (fr) 2021-12-17 2022-01-24 Procédé de production d'un matériau revêtu hautement résistant à l'abrasion comportant une couche de conversion sur un substrat en aluminium, en particulier en forme de bande

Country Status (2)

Country Link
DE (1) DE102021133647A1 (fr)
WO (1) WO2023110154A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3594289A (en) * 1967-11-15 1971-07-20 Howson Ltd W H Process for preparing a presensitized photolithographic printing plate
US4681668A (en) * 1984-11-05 1987-07-21 Alcan International Limited Anodic aluminium oxide film and method of forming it
WO2000029784A1 (fr) 1998-11-12 2000-05-25 Alusuisse Technology & Management Ag Reflecteur a surface resistante
DE10014035A1 (de) 2000-03-22 2001-10-04 Electro Chem Eng Gmbh Gefärbte Konversionsschicht
EP1493498A1 (fr) 2003-06-26 2005-01-05 Aluminium Féron GmbH & Co. KG Procédé de production d'un substrat métallique comprenant un revêtement de protection et procédé de production d'un laminé composite comprenant un substrat métallique ainsi produit
US20180250925A1 (en) * 2017-03-02 2018-09-06 Eastman Kodak Company Lithographic printing plate precursors and method of use

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3594289A (en) * 1967-11-15 1971-07-20 Howson Ltd W H Process for preparing a presensitized photolithographic printing plate
US4681668A (en) * 1984-11-05 1987-07-21 Alcan International Limited Anodic aluminium oxide film and method of forming it
WO2000029784A1 (fr) 1998-11-12 2000-05-25 Alusuisse Technology & Management Ag Reflecteur a surface resistante
DE10014035A1 (de) 2000-03-22 2001-10-04 Electro Chem Eng Gmbh Gefärbte Konversionsschicht
EP1493498A1 (fr) 2003-06-26 2005-01-05 Aluminium Féron GmbH & Co. KG Procédé de production d'un substrat métallique comprenant un revêtement de protection et procédé de production d'un laminé composite comprenant un substrat métallique ainsi produit
US20180250925A1 (en) * 2017-03-02 2018-09-06 Eastman Kodak Company Lithographic printing plate precursors and method of use

Also Published As

Publication number Publication date
DE102021133647A1 (de) 2023-06-22

Similar Documents

Publication Publication Date Title
DE102007057777B4 (de) Verfahren zur Herstellung eines Bauteils aus Aluminium und/oder einer Aluminiumlegierung sowie Verwendung des Verfahrens
DE69912966T2 (de) Verfahren zur oberflächenbehandlung von gegenständen aus aluminium
DE2432364B2 (de) Verfahren zum Beschichten von Aluminium oder Aluminiumlegierungen
DE1669110C3 (de) Mittel zur Erzeugung eines Schutz- und Grundierungsüberzuges mit antikorrosiver Wirkung auf Metallen
DE60029253T2 (de) Methode zum lackieren von smc-teilen
WO2009056635A2 (fr) Couche anticorrosion antirayures et extensible pour substrats en métal léger
DE69820888T2 (de) Beschichteter aluminium werkstoff
EP2794939A2 (fr) Procédé de structuration d'une surface d'une pièce d' uvre
EP2922986B1 (fr) Procédé de nanostructuration et d'anodisation d'une surface métallique
DE102014213873A1 (de) Silikatbeschichtung mit freisetzbaren Metallkationen
EP2145980A1 (fr) Surface d'acier noble coloré et procédé de coloration d'acier noble
EP3408431B1 (fr) Bande d'alliage d'aluminium pour joint de colle
EP1570109B1 (fr) Procede pour revetir des substrats metalliques avec un agent de revetement polymerisable par polymerisation radicalaire, et substrats ainsi revetus
WO2009098099A2 (fr) Revêtement multifonction de pièces en aluminium
EP2151481A1 (fr) Solution aqueuse et procédé de revêtement de surfaces métalliques et utilisation d'acide silique modifié ou de composition de concentré pour la préparation d'une solution de revêtement aqueuse
DE102019204224A1 (de) Verfahren zur Neukonditionierung von feuerverzinkten Oberflächen
EP2729604B1 (fr) Procédé de formation d'une couche promotrice d'adhésion sur une surface d'un matériau à base de titane
WO2023110154A1 (fr) Procédé de production d'un matériau revêtu hautement résistant à l'abrasion comportant une couche de conversion sur un substrat en aluminium, en particulier en forme de bande
DE102020131128A1 (de) Vakkuumimprägnierung von durch anodische Oxidationsbeschichtung (AOC) behandelten Oberflächen auf Ventilmetallsubstraten
DE2454219A1 (de) Beschichtungsverfahren eines aluminiums oder einer aluminiumlegierung
EP3404070A1 (fr) Composites à revêtement sélectif et procédé de fabrication
DE2519132C3 (de) Verfahren zur kontinuierlichen Herstellung oberflächengeschützter stranggepreßter Formstücke aus Aluminium oder Aluminiumlegierungen
EP1493498B1 (fr) Procédé de production d'un substrat métallique comprenant un revêtement de protection et procédé de production d'un laminé composite comprenant un substrat métallique ainsi produit
DE102011055644A1 (de) Verfahren zur Erzeugung einer schwarzen oxidkeramischen Oberflächenschicht auf einem Bauteil aus einer Leichtmetalllegierung
WO2006027007A1 (fr) Procede pour façonner des toles d'aluminium dotees d'une surface de decoration

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22703568

Country of ref document: EP

Kind code of ref document: A1