KR100514962B1 - Method for gloss coating of parts, preferably for motor vehicles, especially motor vehicle wheels, and a part coated in this fashion - Google Patents

Abstract

The present invention relates to a part gloss coating, preferably for vehicles, in particular for vehicle wheels and for coating parts of this type.

Vehicle wheels have been coated by various colorings to the desired color until now. The metallic tint effect is achieved by mica coloring. It is an object of the present invention to provide a variety of metallic luster colors to the object, in particular to the vehicle wheel.

The first step forms a corrosion resistant gloss initial coating layer, as known, and the second step forms a high gloss layer applied by magnetron atomization thereon. In the third step, a transparent and wear resistant top surface coating layer is then applied according to known methods. The parts are mechanically pre-treated and provided with a protective or surface layer.

At this stage, the vehicle parts, in particular the vehicle wheels, are produced in a wide variety of colors with a layer of shiny metal.

Description

TECHNICAL FOR GLOSS COATING OF PARTS, PREFERABLY FOR MOTOR VEHICLES, ESPECIALLY MOTOR VEHICLE WHEELS, AND A PART COATED IN THIS FASHION}

The present invention preferably relates to a method for forming a glossy coating on a vehicle part, in particular on a vehicle wheel or rim. The method is preferably used to coat the light metal wheel to form a metallic luster on the light metal wheel. The method is likewise applicable to interior and exterior parts of vehicles. In addition, the method can be used in daily necessities of various ranges of use, in order to achieve special visual effects or improved properties and corrosion protection. This includes, for example, the housing of the device and the device.

The subject matter of the invention relates to a vehicle part, preferably a vehicle wheel, manufactured according to the method.

It is known to provide anticorrosive lacquer layer systems for objects of this type, in particular vehicle wheels (German Utility Model No. 81 03 758). On the primer layer of the cathodic deposition electrodeposition coating, a colored surface lacquer layer cured by an electron beam is formed. To this layer is applied another surface lacquer layer of transparent lacquer, which is likewise cured by electron beam. This has the disadvantage that a limited metallic luster is produced.

It is already known to provide paint layers on light metal wheels (European Patent No. 0 525 867). Two layers are applied for this purpose, the two layers being lacquer layers. The first layer consists of a lacquer with primary coloring and the second layer consists of a clear lacquer containing Mica Pigment. This method has the disadvantage that it does not form pure metallic luster but merely mimics it by pigment.

It is known to paint layers with various color and gloss effects through vacuum coating, in particular magnetron atomization, on the object.

In a vacuum chamber, the coating object is disposed opposite one or a plurality of targets of the material or element of the layer to be applied. Between the target and the object, a gas discharge is ignited so that a plasma is formed and the target particles are atomized. Metals, metal alloys or metal mixtures are used as target materials. However, the metal mixture can be applied through an active magnetron atomization reaction by metal atomization and further inhalation of the reaction gas into the vacuum chamber, for example O ₂ , N ₂ . By means of the corresponding material selection, in some cases in conjunction with the process gas, the layers can be produced in a variety of colors.

In order to protect the atomized layer from stresses against corrosion and damage due to mechanical wear, a hard wear resistant layer is applied as a surface layer to the glossy metallic layer by PVD and CVD processes. A disadvantage of the polished metallic layer protected in this way is that it is not striking, for example, to withstand the high mechanical corrosion stresses that a vehicle wheel receives. Moreover, the manufacturing cost of a protective layer is too high.

It is an object of the present invention to provide a method for forming a glossy coating on a component, preferably a component of a vehicle, in particular a vehicle wheel, to produce a variety of glossy metallic colors on its own surface or area. It is preferred that a coating amount wheel, preferably a visible surface, of metal, in particular a light metal alloy, is coated. Glossy coatings must be resistant to corrosion and overcome mechanical stress, for example in the wear and chipping of vehicle wheels. The method and thus the coated parts can be economically manufactured and coated.

The object of the invention is achieved through the features of claims 1, 2 or 3 and 11. Another preferred embodiment is described in the dependent claims of claims 4 to 10 and 12 to 21.

According to the invention, a glossy coating of the visible area of a part, in particular a vehicle wheel, preferably a wheel, is produced by a combination of multiple layers. In one embodiment, in a first step, a corrosion resistant varnish lacquer base layer, for example consisting of powdered stove-enamel or sputter enamel of optimum properties is applied in a known manner. In a second step, a high gloss layer having a thickness of 10 nm to 5 μm, preferably 100 nm to 500 nm, is applied on the part to be coated by magnetron atomization in a vacuum chamber. The high gloss layer is produced by metals, metal alloys or metal mixtures depending on the color produced. Corresponding variants of magnetron atomization are used depending on the color that can be formed of the high gloss layer and as the coating material used, ie depending on the target material. An essential variant is a target of coating material through the inhalation of reactant gases or reactant gas compounds such as O ₂ , N ₂ , low molecular hydrocarbons, or through pulsed magnetron atomization in which inert atomization, direct current atomization or electrical energy is pulsed. Active atomization. It is also possible for one or more targets to be used, which in the case of the use of multiple targets is preferably switched selectively as an anode and a cathode.

In the production of high gloss layers consisting of complex components, for example titanium-aluminum-nitrides, reaction pulse magnetron sputters are used, as is particularly well known, for which simple targets of titanium and aluminum metals are active nitrogen Used as an atmosphere. The pulsed magnetron sputters on the one hand allow a stable, safe and reproducible process, which is not possible due to flashover, so-called arcing, which occurs frequently with other coating methods. On the other hand, through pure electrical means, ie through the adjustment of the pulse to the resting period, the composition of the layer and the color of the gloss layer are adjusted and kept constant within a short range for the targets of two different metals. In the final step, a transparent wear resistant surface lacquer layer is applied to the high gloss layer by known methods. The surface lacquer layer is based on acrylate or polyurethane or epoxy resin or consists of an organic inorganic compound, preferably Ormocer and has a thickness of 0.5 μm to 100 μm. Only a combination of two known method steps of spraying the layer with vacuum and then applying lacquer between the two known steps can provide a layer system that meets the high demands on visual appearance and corrosion protection.

A preferred embodiment of the glossy coating consists in mechanically polishing the surface of the part, in particular the area to be coated, and then applying the chromate layer prior to applying the corrosion resistant varnish lacquer base layer.

In another configuration of the method, a powdered lacquer layer is preferably formed on the chromate layer after the chromate layer and before the corrosion resistant lacquer base layer.

A preferred embodiment of the method is that in the CVD process the lacquer surface layer is coated onto the high gloss layer as the last layer of the layer system.

Magnetron atomization results in layers with the above visual decorative features that are impossible to manufacture with conventional coating methods in terms of color and gloss. Colors that can be produced with a wide range of choices are metallic luster, which means that they cannot be imitated through corresponding coloring. The color palette is available from dark silver and pale silver to gold, reddish brown to purple. Preferably the system represents titanium-aluminum-nitrogen. Many colors can be produced in the system. However, other systems, for example zirconium-aluminum-nitrogen and titanium-zirconium-nitrogen, can be used for producing another color. Other colors may be made of copper or brass.

Furthermore, spraying high gloss layers using magnetron atomization is simple and economical. Coating of three-dimensional and complex shaped parts is well achieved in all respects, which cannot be achieved by other vacuum coating methods such as electron beam vapor, arc vapor, boat vapor or ion plating.

Another advantage is that with the method according to the invention a relatively sensitive high gloss layer can be protected against many stresses and environmental influences, for example corrosion by alkaline liquids and acids. The elasticity of the relatively thick lacquer base layer and the surface lacquer layer substantially contributes to mitigating large mechanical stresses such as chapping and wear. In addition, corrosion protection of the part to be coated can be achieved with a lacquer foundation layer and the roughness of the surface can be made uniform, such as forged or cast light metal wheels. By this method, the next coating is made of a high gloss layer, and the adhesion of the layer is improved. It is possible to precisely adjust the gloss of the gloss coating by adding an additive to become a transparent surface lacquer layer, so that a plurality of gloss grades meet the aesthetic and fashionable requirements.

Another advantage of the present invention is to perform mechanical polishing on the surface to be coated before forming the lacquer base layer. In addition, the adhesion of the high gloss layer is improved when it is carried out through heating and / or etching or adhesion mediation layer of inert gas plasma or reaction gas plasma before formation of such layer. For light metal wheels it is advantageous to coat only the visible surface rather than the entire surface. This reduces the coating cost.

The method for gloss coating can be applied for the coating of parts made of steel, light metals such as magnesium, titanium, aluminum and their alloys and plastics. Vehicle parts made of such materials are, for example, mirror cases, fan grates, radiator grilles, door rats, actuation buttons, instrument panel parts and the like. The interior and exterior parts of every vehicle can be provided with a glossy coating. Such parts can be cast parts, spray molded parts or plastic parts to sheet metal parts. Particular conditions in the coating of plastic parts are to consider adjusting the process parameters in coating, especially in the use of sprays of high gloss layers and in the case of initial glow cleaning.

Hereinafter, another modified embodiment of the present invention will be described in detail. Vehicle wheels of light alloys aluminum, magnesium and titanium, in particular the wheel spider, have a purple glossy coating. The vehicle wheel is mechanically polished and then coated with powdered stove enamel of optimum properties in the first stage as is known.

In a second step the vehicle wheel is then positioned in the vacuum chamber such that the outside of the vehicle wheel is positioned opposite two targets of the magnetron atomization source disposed in the vacuum chamber. One target is made of aluminum and the other is made of titanium. After the vacuum chamber has been evacuated, argon is introduced into the vacuum chamber and a corona discharge is ignited in the inert atmospheric gas. The high gloss layer is formed through pulsed magnetron atomization as is known. Aluminum targets and titanium targets alternately operate as the positive and negative poles of the corona discharge at a frequency of 10 KHz. The total power supplied to the target is 15 kW. In addition, 80 sccm nitrogen is introduced into the vacuum chamber as the reaction gas, and the working pressure is set to 2 × 10 ⁻³ mbar. The vehicle wheel is rotated around the coating symmetry axis during coating to obtain a uniform coating. A purple 200 nm thick high gloss layer is applied on the vehicle wheel for a three minute coating time. In the third step, a surface lacquer layer based on polyurethane having a thickness of 30 μm is finally coated on the high gloss layer by a known method.

In the above example, when the parts of the vehicle wheel are made of magnesium, it is preferable to carry out the preceding mechanical grinding as so-called smooth grinding before the formation of the layer system. However, this step may be advantageous for removing impurities on the surface that may adversely affect the quality of the coating, in the case of parts of other materials.

The method may be formed by mechanically polishing, preferably by applying a chromium layer as the first layer and forming a powdered lacquer layer thereon.

The chromium layer is preferably formed chemically and in particular has the purpose of anticorrosive action, in which case the lacquer base layer can have a reduced action as an incidental anticorrosion layer. The powder lacquer layer forms a plastic resist to external influences, such as, for example, chipping on a vehicle wheel.

According to the invention, a method of forming a glossy coating on a component, preferably a vehicle component, in particular a vehicle wheel, has the effect of producing a variety of glossy metallic colors on its own surface or area.

Claims (21)

A method of forming a glossy coating by forming a layer system on a vehicle part, in particular a vehicle wheel, Forming an anti-corrosion polished lacquer base layer, Spraying a high gloss layer of metal, metal alloy or metal mixture with a magnetron in vacuo, Forming a transparent, wear-resistant surface layer of lacquer. A method of forming a glossy coating by forming a layer system on a vehicle part, in particular a vehicle wheel, Mechanically polishing the surface, Forming a chromium layer, Forming an anti-corrosion polished lacquer base layer, Spraying a high gloss layer of a metal, metal alloy or metal compound with a magnetron under vacuum; Forming a transparent, wear-resistant surface layer of lacquer. A method of forming a glossy coating by forming a layer system on a vehicle part, in particular a vehicle wheel, Mechanically polishing the surface, Forming a chromium layer and Forming a powdered lacquer layer, Forming an anticorrosive lacquer foundation layer, Spraying a high gloss layer of a metal, alloy or metal compound in a vacuum with magnetton, Forming a transparent, wear-resistant surface layer of lacquer. The method of claim 1, wherein the surface layer is formed on a high gloss layer in a CDV process. The process according to any one of claims 1, 2 or 3, wherein before the high gloss layer is sprayed, the pretreatment in vacuum is preferably carried out by heating and / or etching in an inert gas plasma or a reactive gas plasma. Characterized in that performed. The method according to claim 1, wherein the pretreatment in vacuum is performed by forming an adhesion mediation layer before the high gloss layer is sprayed. The method according to any one of claims 1, 2, or 3, wherein the high gloss layer is sprayed in an inert gas atmosphere or a reactive gas atmosphere by direct current atomization or pulse magnetron atomization. 8. Process according to claim 7, characterized in that a gas or mixed gas, preferably O ₂ , N ₂ or low molecular hydrocarbons, is introduced as the reaction gas. 8. The method of claim 7, wherein the part to be coated is moved relative to the magnetron target upon spraying a high gloss layer. The method according to claim 1, wherein the gloss of the part to be coated is adjusted by the addition of colorants to the transparent surface lacquer layer. In coating parts consisting of metals or metal alloys, in particular light metals, with a layer system formed on the surface, A layer system is formed on at least the visible surface of the part, the layer system comprising at least an anti-corrosion polished lacquer layer, a high gloss layer of a metal metal alloy, or a metal compound, and a transparent, abrasive wear resistant surface layer of lacquer. Coating parts, characterized in that. The coating component according to claim 11, wherein an adhesion intermediate layer is formed below the high gloss layer. The coating component according to claim 11, wherein a chromium layer is formed below the lacquer foundation layer. The coating component according to claim 13, wherein a powdered lacquer layer is formed between the chromium layer and the lacquer base layer. 12. The coating component according to claim 11, wherein the lacquer foundation layer is a powdered stove enamel of optimum properties having a thickness of 100 µm to 500 µm, preferably 30 µm to 300 µm. 12. The coating component according to claim 11, wherein the high gloss layer has a thickness of 10 nm to 5 m, preferably 100 nm to 500 nm. The coating component according to claim 11, wherein the high gloss layer is a compound composed of titanium aluminum nitrogen. The coating component according to claim 11, wherein the coating component is a compound composed of the high gloss layer zirconium aluminum nitrogen. The coating component according to claim 11, wherein the high gloss layer is a compound composed of titanium zirconium nitrogen. 12. A coating component according to claim 11, wherein the surface layer is an organic or inorganic compound, preferably an ormocer, having a thickness of 0.5 μm to 20 μm, preferably 2 μm to 5 μm. The coating component according to claim 11, wherein the surface lacquer layer is an organic layer having a thickness of 1 μm to 100 μm, preferably 20 μm to 30 μm, based on acrylate or polyurethane or epoxy resin.