Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
  • B05D5/06—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain multicolour or other optical effects
  • B05D5/067—Metallic effect
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/10—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by other chemical means
  • B05D3/107—Post-treatment of applied coatings

Definitions

• the present invention relates to a process for producing coated substrates and to such coated substrates.
• Non-metallic as well as in particular metallic substrates are often provided with one or more coatings in order to achieve a particular decorative effect and / or to protect the substrate against certain external influences.
• coatings often serve to increase the corrosion protection.
• metallic and effect coatings have proved particularly suitable for metallic substrate surfaces.
• metal pigments for example aluminum pigments. These are used in particular in the form of platelets, flakes or flakes.
• an aluminum metal effect paint consisting essentially of either i) white pearlescent pigment and aluminum pigment, ii) white pearlescent pigment, aluminum pigment and white pigment, iii) bismuth oxychloride pigment or iv) bismuth oxychloride pigment and pearlescent pigment, aluminum pigment and / or white pigment
• an aluminum metal effect paint consisting essentially of either i) white pearlescent pigment and aluminum pigment, ii) white pearlescent pigment, aluminum pigment and white pigment, iii) bismuth oxychloride pigment or iv) bismuth oxychloride pigment and pearlescent pigment, aluminum pigment and / or white pigment
• effect basecoats with good adhesion to plastic substrates made of polypropylene which, when using paint systems containing binders with physical drying power, chlorinated polyolefins having a chlorine content of 15 to 35 weight percent and having a molecular weight of 7000 to 130000, cellulose acetobutyrate, effect pigment and solvent.
• chlorinated polyolefins having a chlorine content of 15 to 35 weight percent and having a molecular weight of 7000 to 130000, cellulose acetobutyrate, effect pigment and solvent.
• a method for painting motor vehicles is described, with which an effect coating can be applied in only one operation on primed in the usual way metal body panels.
• lacquers containing beta-modification copper phthalocyanine pigments which are at least 50% by weight of platelets at least 10 ⁇ m long and at least 3 ⁇ m wide, and where the ratio of length to width is at least 3, 3: 1 and the pigment has a reflection maximum between 610 and 640 and between 710 and 740 nm.
• a paint has to contain as binder a mixture of acrylate resins and / or saturated polyesters, each having an OH number of 40 to 200, and a substantially equivalent amount of aliphatic polyisocyanates crosslinking therewith. Finally, such a paint is applied in a single layer with a dry film thickness of 30 to 50 microns and harden.
• a particularly good order of a metallic effect paint decorative layer succeeds after the DE 197 35 540 C1 if, for the purpose of priming at first, a filler layer of a precrosslinkable powder coating having a layer thickness in the range from 30 ⁇ m to 250 ⁇ m is used.
• the present invention was therefore based on the object of making available a coating method and system which can be used to obtain a decoratively perfect metallic effect coating with very good adhesion to the substrate independently of the substrate.
• the present Another object of the invention was to provide such metallic effect coatings which are provided with outstanding corrosion protection.
• first metal should also include the alloys mentioned above under d).
• second metal is intended in the context of the present invention elements of the 4th and 5th group of the Periodic Table of the Elements or compounds of these elements with the above e) connection components, z. For example, oxides.
• the metallic particles are preferably platelet-shaped metal particles, for example platelet-shaped aluminum particles.
• the purity of the metals used for the metallic particles, preferably of the aluminum is at least 80% by weight, preferably more than 90% by weight, most preferably at least 99% by weight.
• the metallic particles of the coated substrates obtainable by the process according to the invention, in particular in the metallic particles present on the surface or in the surface region of the binder, there is at least one oxide, double oxide, oxide hydrate, sulfide, halide, nitride, carbide, Carbonitride, boride, silicide, oxyhalide and / or salt of an element of the 4th or 5th group of the Periodic Table of the Elements or mixtures thereof.
• the abovementioned compounds are present substantially uniformly distributed in the metallic particles, in particular in the metallic particles which are located on the surface or in the surface region of the decorative lacquer layer.
• the concentration of these compounds incorporated in the metallic particles can change more or less strongly over the thickness of the particles, also continuously, stepwise or in any other way, for example abruptly.
• these compounds may be present or embedded substantially exclusively in the region of the entire surface of the metallic particles or in the region of only a part of the surface of the metallic particles.
• the particles treated with the aqueous system may accordingly also be present as a complete or locally intimate admixture or as an optionally only phased metal composite particle containing the first metal as described above and embedded therein at least one compound of the second metal, in particular at least one acid, an oxide, double oxide, oxide hydrate, sulfide, halide, nitride, carbide, carbonitride, boride, silicide, oxyhalide and / or salt of the second metal are understood.
• the embedded or embedded oxides zirconium oxides, titanium oxides or hafnium oxides, the oxifluorides zirconium oxifluorides, titanium oxyfluorides or hafnium oxyfluorides, the acids fluoric acid, fluorotitanic acid or Fluorhafniumklare and the salts fluorozirconate, fluorotitanates or Fluorhafniate represent.
• oxide-bound zirconium for example oxides of zirconium such as zirconium dioxide, zirconium oxifluorides and / or double oxides of zirconium, for example aluminum / zirconium oxides, are present in the metallic particles.
• Suitable substrates include, for example, metals, precious metals, metal alloys or glass, ceramics, composite fiber materials, carbon materials, plastics, wood or chipboard.
• plastics are e.g. PVC, polyurethanes, polyesters, e.g. PBT and PET, polyolefins, especially polypropylene, polyamides, polystyrene, styrene (co) polymers such as ABS, SAN, ASA or MABS, and polyoxyalkylenes, e.g. POM, dar.
• suitable substrates may be present in addition to metallic components or sections and non-metallic components or sections.
• shaped bodies of all metals, metal alloys and precious metals are suitable as metallic substrates.
• suitable substrates are those of aluminum, iron, steel, stainless steel, copper, brass, magnesium, iridium, gold, silver, palladium, platinum, ruthenium, molybdenum, nickel, bronze, titanium, zinc, lead, tungsten or manganese and their Called alloys.
• Preferred metal substrates or metal substrate surfaces comprise or in particular consist of aluminum or aluminum alloys, magnesium or magnesium alloys or titanium or titanium alloys or of steel or stainless steel. Particular preference is given to the metallic substrates on aluminum and aluminum alloys.
• diecast substrates e.g. Zinc diecasting, are particularly suitable.
• the aqueous system contains at least one acid, an oxide, double oxide, oxide hydrate, halide, oxyhalide or salt of an element of the 4th or 5th group, in particular of titanium or zirconium, or mixtures thereof ,
• the aqueous system is conveniently adjusted to a pH in the range of 1.5 to 6.5.
• the compounds of the elements of the 4th or 5th group of the Periodic Table of the Elements present in the aqueous system are preferably at least partially introduced or embedded in at least one part of the metallic particles.
• the decorative lacquer layer is exposed to the aqueous system under pressure, in particular in the form of liquid jets.
• a particularly effective entry or embedding of the above-mentioned compounds of the 4th and 5th group of the Periodic Table of the Elements in at least a portion of the metallic particles of the decorative coating layer succeeds.
• the aqueous system may e.g. in the form of a solution, a suspension or an emulsion.
• the aqueous system is used as a solution, i. the abovementioned compounds, salts and / or acids are present substantially dissolved at least before the application.
• the conductance of the aqueous system used is preferably in the range from 100 to 2000, particularly preferably in the range from 150 to 1500 and in particular in the range from 200 to 1000 ⁇ S / cm.
• the temperature of the aqueous system in the process of treating the substrate is in the range of 15 to 50 ° C, preferably in the range of 20 to 40 ° C.
• a treatment duration of 20 to 120 seconds is sufficient to obtain the substrate according to the invention.
• the coated surface of the substrate is subjected to a rinsing step with, in particular demineralized, water.
• the drying step can be carried out, for example, at temperatures in the range from 120 to 180 ° C, for example at about 140 ° C.
• the water used for rinsing preferably has a conductance of less than 60 mS / cm, preferably less than 50 mS / cm and in particular less than 35 mS / cm.
• the respective last rinse before the subsequent process step or before a drying process has the above-mentioned guide values.
• the pH and / or the conductance of the aqueous system are preferably kept substantially constant for the duration of the treatment of the metal layer, in particular within the abovementioned ranges.
• the substrate provided with the decorative varnish layer may be e.g. by immersion, rinsing or spraying with the aqueous system described above, containing at least one of said compounds of the second metal.
• the decorative lacquer layer is subjected to this aqueous system under elevated pressure, for example in the form of high-pressure water jets. It has proven to be useful to direct a variety of fine single water jets on the substrate.
• Suitable pressures for exposure to the aqueous system are e.g. above 0.2 bar, preferably in the range of 0.5 to 50 bar and particularly preferably in the range of 0.2 to 15, in particular from 0.9 to 1.5 bar. These pressures are measured on the surface of the metal layer.
• the compounds of the second metal which are present in the aqueous system e.g. present as acid or salt, in which metallic particles are converted into an oxide, double oxide, oxide hydrate or oxyhalide.
• Suitable acids derived from a group 4 element include, for example, hydrofluorozirconic acid (H 2 ZrF 6 ), fluorotitanic acid (H 2 TiF 6 ) and fluoro hafnic acid (H 2 HfF 6 ). Of course, mixtures of different acids can be used. These fluoric acids can be used both in the pure state and also containing impurities, for example fluoric acid. In the aqueous systems, the acids may be present, for example, in amounts of up to 5% by weight, in particular of up to 3.5% by weight, based on the total weight of the aqueous system. Fluoric acid may also be present in the aqueous systems, eg in amounts ranging from 0.1 to 3% by weight.
• ammonium zirconium carbonate which is available, for example, from Magnesium Electron Inc., under the trade name Bacote 20, used ((NH 4 ) 2 [Zr (OH) 2 (CO 3 ) 2 ] .nH 2 O). It is also possible to use alkali metal and ammonium fluorozirconates, for example Na 2 ZrF 6 , KZrF 6 , (NH 4 ) ZrF 6 , as well as zirconium nitrates, zirconium oxynitrates, zirconium carbonates, zirconium fluorides or zirconium sulfate.
• the compounds based on the 4th group can be used as such or in any mixture with each other. The same applies to the compounds of the 5th group.
• aqueous systems in addition to the compounds mentioned or mixtures thereof further ingredients.
• Nitric acid, fluoric acid, phosphoric acid, salts of said acids, ammonium bifluoride and ammonium sulfate into consideration.
• a suitable titanium salt provides e.g. Ammonium titanium fluoride.
• the aqueous system preferably contains fluoride ions in free and / or complexed form.
• Suitable complexed fluoride ions include fluoroborate salts and acids as well as alkali metal and ammonium bifluorides.
• complex fluorides of titanium, zirconium, hafnium, silicon and / or boron are particularly suitable.
• complex fluorides are used as zirconium.
• Suitable aqueous systems may preferably be in addition to the acid, an oxide, double oxide, oxide hydrate, sulfide, halide, nitride, carbide, carbonitride, boride, silicide, oxyhalide and / or salt of the second metal, preferably based on a 4th group element of the Periodic Table of the Elements (IUPAC, formerly designated Group IVb or IV-B), in particular zirconium, titanium and / or hafnium, preferably zirconium, at least one polymeric compound dissolved in the aqueous composition, in emulsion form or in undissolved dispersed form Particles may be present.
• IUPAC Periodic Table of the Elements
• polymeric compounds may be mentioned in particular the polyacrylic acid and its salts and esters. These acids, esters and salts may be present in the aqueous solution in dissolved or dispersed form.
• the amount of polymer component can be varied widely and is preferably in the range of 0.1 to 0.5 g per liter.
• the process according to the invention comprises after process step a) and before process step d) as process step b) the application of at least one conversion layer to the substrate.
• conversion layers can be found, for example, in US Pat US 2,825,697 and the US 2,928,763 described.
• the conversion layer may, for example, also be conventional passivation layers based on nickel, chromium and zinc compounds.
• the method further comprises after step a) and before step d) as process step c) the application of at least one first and optionally at least one second primer layer on the substrate.
• at least one first and / or at least one second primer layer is applied at least in regions to the conversion layer.
• an upstream mechanical smoothing of the metal substrate surface may be provided, for example by means of grinding and / or polishing or burnishing
• the first and / or the second primer layer can be applied, for example, by means of a wet-paint method and / or a powder-coating method. Suitable examples are powdered polyester resin compounds and epoxy / polyester powder. Suitable epoxy resins as primer layer materials are known commercially, for example, under the trade name "Valophene". As the first and second primer layers, there are also those based on a urethane resin, as in U.S. Pat US 4,431,711 described, into consideration. Alternatively, it is also possible to use polyester or polyacrylate materials such as those described in U.S. Pat WO 2004/014646 A1 be highlighted. Very particular preference is given to the purpose of priming on wet paint process.
• primer methods in which the curing of the primer layer is not thermal, but by means of UV irradiation. When curing by means of UV radiation regularly no additional heating is required, and in general no heat is generated in this case.
• Suitable powder coating, wet paint and UV-curing coating systems and their application are well known to those skilled in the art.
• one or several primer layers can be applied to smooth the surface.
• the primer layer thus regularly constitutes a so-called smoothing layer.
• smoothing layer With a primer layer, all angular ranges are generally reached, so that surface roughnesses can also be compensated in these areas.
• a further aspect of the method according to the invention further provides that the decorative lacquer layer is applied according to method step d) before the first and / or second primer layer has completely cured.
• the process according to the invention may further comprise, after process step e) as process step f), the application of at least one, in particular transparent, topcoat.
• the topcoat can be e.g. a clearcoat or a transparent powder, and is preferably applied by a wet-paint method or a powder-coating method. Furthermore, the invention provides that the cover layer may contain at least one dye or a pigment.
• the cover layer or the topcoat can generally be one-, two- or multi-component paints. Clearcoats are preferred here. These clearcoats may be e.g. be chemically cross-linking two-component, one-component thermosetting or UV-curable coatings.
• the topcoat or clearcoat layer can be cured in a separate step subsequent to the production and curing of the decorative lacquer layer or together with the decorative lacquer layer and / or the first or second primer.
• the substrate may also be used as a topcoat or in addition to the cover layer described above in particular also suitable, known in the art glazes.
• This can be used, for example, brass, titanium and gold tones as well as individual Shades such as red, blue, yellow, green, etc. and all the anodizing colors are easily set.
• Another advantage is also that with the inventive method especially wide margins in the color design result, if one tunes the colors or color effects of decorative lacquer layer and topcoat and in particular of primer, decorative lacquer and topcoat each other.
• a dark colored primer, a high gloss decorative lacquer layer, and a transparent topcoat products with matte chrome finish are obtained without, however, relying on the use of chromium.
• the decorative lacquer layer is applied in a thickness which is still slightly translucent for the color of the substrate or primer.
• the decorative lacquer layer applied to the substrate by the method according to the invention can be, for example, a so-called effect lacquer layer or a so-called metallic lacquer layer.
• this decorative lacquer layer is treated with a first aqueous system according to method step e) such that a first decorative lacquer layer containing metallic particles, containing or consisting essentially of aluminum, on the first decorative lacquer layer treated in this way Gold, silver, lead, vanadium, manganese, iron, cobalt, nickel, copper, palladium, platinum, titanium, zinc, magnesium or alloys of these metals or containing or consisting essentially of brass, bronze or stainless steel, and that second Decorative lacquer layer comprising a second aqueous system containing at least one acid, an oxide, double oxide, oxide hydrate, sulfide, halide, nitride, carbide, carbonitride, boride, silicide, oxyhalide and / or salt of a 4th or 5th group element of the Periodic table of the elements or mixtures thereof, is treated.
• the method steps d) and e) can not only be run twice in succession, but can also be repeated several times, for example at least three times or at least four times in succession be run through, for example, to achieve a particularly intense and consistent decor effect, especially metallic effect.
• a different decorative lacquer layer can be applied in the sense of the present invention.
• the same decorative lacquer layer is applied in each application step.
• a different aqueous system in the context of the present invention can be used.
• the same aqueous system is used in each treatment step.
• the decorative lacquer layer to be applied in process step d) represents a decorative lacquer layer to be cured or dried out and that this decorative lacquer layer is treated with the aqueous system according to process step e) prior to its complete curing and / or drying.
• the drying step in decorative lacquer layers is also known as the so-called peeling step.
• water-dilutable coating compositions can be used for the decorative lacquer layer.
• These coating compositions contain suitable binders, for example polyester, polyacrylate, polyurethane or aminoplast resins, e.g. B. in wasserver Parkernbarer form.
• the coating composition for the decorative paint layer comprises e.g. an aqueous polymer dispersion comprising an acrylate copolymer and a non-associative thickener.
• pearlescent pigments such as pearlescent pigments, LCP pigments (liquid crystal polymer) or OV pigments (optical variable), in the coating compositions used for the decorative lacquer layer.
• Common pearlescent pigments include, for example, metal oxide coated metal pigments, for example, titanium dioxide coated, iron oxide coated, or mixed oxide coated aluminum.
• Pearlescent pigments also include coated mica.
• OV pigments are generally pigment platelets with a special one multilayer thin-film interference structure, the layers being composed of a highly reflective metal layer such as aluminum or chromium, a transparent dielectric layer of titanium dioxide or silicon dioxide and a semitransparent metal layer of, for example, nickel or aluminum.
• proportions of color-providing organic and / or inorganic pigments may also be present in the coating composition for the decorative lacquer layer.
• the coating compositions used for the decorative lacquer layer in one embodiment contain solvents in an amount of, based on the coating composition, 20 to 80, advantageously 30 to 70, in particular 40 to 65 wt .-% of solvents, for. B. water.
• the coating compositions for the decorative coating layer may contain conventional coating additives.
• coating additives By way of example, reference is made to rheology-influencing agents, thickeners, anti-settling agents, leveling agents, light stabilizers, antifoams, wetting agents or mixtures of these components.
• the decorative lacquer layer can be applied to the substrate by means of known application methods, for example by means of spraying, rolling, knife coating, brushing, roller coating, flooding or dipping.
• spray or spray application can be used, for example, on known compressed air or Rotationszerstäubungs réellesvon.
• the decorative coating layer is applied to the substrate by means of spraying, in particular using pressure, for example compressed air.
• pressure for example compressed air.
• a concentration gradient of metallic particles within the decorative lacquer layer regularly occurs, with the result that the concentration of metallic particles in the direction of the substrate surface decreases. Accordingly, in this variant, the majority of the metallic particles are often present on or on, and optionally in the near-surface region of the decorative lacquer layer.
• These metallic particles are particularly suitable for the introduction of the abovementioned compounds of the elements of groups 4 and 5 of the Periodic Table of the Elements by application of the described aqueous system in the sense of the present invention. Without being bound by any theory, it is presently believed that it may be that described above Distribution of metallic particles within the decorative coating layer could be due to electrostatic friction phenomena. Of course, the effect according to the invention is also achieved, for example, when the metallic particles are substantially uniformly distributed in the decorative lacquer layer.
• Suitable metallic particles for the decorative lacquer layer may, for.
• wet-chemically or by CVD or PVD processes are prepared, for example by application to naturally or artificially produced micrometer-sized platelets.
• Particularly suitable metallic particles have form factors, ie ratios of average longitudinal extent to average thickness, in a range from 10 to 7,000, preferably from 50 to 10,000, and particularly preferably from 70 to 200.
• Preferred average layer thicknesses of the metallic particles present, in particular in platelet form are in a range of 15 to 1000 nm.
• the average diameter of, in particular of platelet-shaped, metallic particles is in the range from 1 to 500 .mu.m, more preferably in the range from 5 to 100 ⁇ m.
• the average diameter is here the d 50 value of the cumulative distribution of the size distribution curve, as it is usually measured by laser diffraction method (Frauenhoferbeugung) by means of suitable devices (for example, Cilas 1064) is measured, based.
• the decorative lacquer layer preferably has a layer thickness not above 150 ⁇ m, advantageously not above 80 ⁇ m, and preferably in the range from 1 to 40 ⁇ m, more preferably in the range from 2 to 35 ⁇ m and particularly preferably in the range from 3 to 30 microns.
• layer thicknesses above 150 ⁇ m for example in the range from 300 to 450 ⁇ m, for example about 400 ⁇ m.
• the metallic particles in the decorative lacquer layer can still always come into contact with it during the treatment with the aqueous system, for example because the metallic particles are present on or in the surface and / or because the aqueous system or its Compounds of the second metal in the Decorative paint layer can penetrate, for example, because this is not fully cured or dried out.
• the cover layer usually has a thickness in the range of 20 to 30 microns.
• coated substrates obtainable by the process according to the invention can be used, for example, as an accessory for the automotive industry, motorcycle construction, bicycle construction or shipbuilding, for rims, in particular light metal rims, wheels, in particular light metal wheels or as a component thereof, for sanitary appliances, in particular as a fitting, or as a component thereof for internal or external body components or as a component thereof, for handles or handle components, in particular door handles or as a component thereof, for profiles or frames, in particular window frames or as a component thereof, for fitting systems or as a component thereof, in particular signs and door plates, for housing or as a packaging or as a component thereof, for interior or exterior components of ships or as a component thereof, for or as a component of or for jewelery, for or as a component thereof, for interior or external components of aircraft or as a component thereof, for internal or external components of buildings or as a component thereof, for radiators or pipes or as a component thereof, for components of elevators or as a component thereof, for components of electronic components or devices or as
• substrates can be obtained which are provided with decorative coatings containing metal particles and which are distinguished by a very good adhesion of the decorative layer to the substrate, even at high concentrations of metal particles in the coating composition used.
• the resulting coated substrates are also characterized by excellent corrosion properties and a very good and consistent glossy effect.

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Citations (11)

• 2008
  • 2008-05-23 EP EP08009472A patent/EP2123366A1/fr not_active Withdrawn
• 2009
  • 2009-05-22 WO PCT/EP2009/003626 patent/WO2009141150A1/fr active Application Filing
  • 2009-05-22 EP EP09749640A patent/EP2296829B1/fr not_active Not-in-force

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