DE202017000347U1 - Plastic component with galvanized and anodised surface for the presentation of optionally colored, corrosion-resistant, decorative metal layers - Google Patents

Abstract

Corrosion-resistant and optionally color-coated metallic decorative plastic components (h) with a chemical pretreatment (b) and deposition of a first conductive metal layer (c) and subsequent electrodeposition of an aluminum (e), wherein the deposited aluminum surface oxidized in a subsequent anodizing process become (f).

Description

The invention describes a component produced in plastic injection molding with a chemical and galvanic pretreatment and preferably a galvanic metal deposition and with an additional electrodeposited aluminum coating, with which in a subsequent anodizing process a high-quality, corrosion-resistant and optionally colored decorative metal coating can be formed.

In the automotive industry, different and differently decorated plastic components are used for visual enhancement. Conventional surface technologies of such surface decorated components are the finished undecorated plastic surfaces by injection molding, painting the plastic surfaces, scoring and etching the tool surfaces to be imaged and molding them by plastic injection molding, galvanizing the plastic surface, decorating in the injection mold by IMD (In Mold Decoration), wherein a Injection molding on a carrier film imprinted printing is molded from a carrier film, the back molding of printed and partially deformed and contour-punched film inserts by the FIM technology, the film insert molding and the metal foil rear spraying.

In addition to all these classic surface technologies, the presentation of metallic surfaces is particularly high in trend, but suggests this surface like no other a high quality and robust appearance.

In addition to the real metal decorated components, so veneered, joined or back-injected components with thin stainless steel or aluminum sheets, metal-coated plastic components are also particularly preferably used as decorative elements.

A type of coating with which it is possible to achieve optically metallic surfaces is, for. As the vapor deposition, to which the PVD process (Physical Vapor Deposition) and their modified technologies such. CVD and PeCVD and others. Here, thin metal layers are deposited in an evacuated vacuum chamber on a plastic component. The material to be deposited is in solid form. The vaporized material moves through the coating chamber and strikes the component to be coated, where precipitation causes film formation. Although the PVD process is generally suitable for representing metallic layers, it has proved to be problematic that the very thin metal coating can not have sufficient resistance to abrasion and corrosion without an additional protective layer. For this reason, it is necessary to apply a protective layer, for example a clearcoat system. In order to achieve a sufficient basic adhesion to the plastic component to be deposited, a coating of a primer is usually necessary.

Another important and industrially important coating is the galvanic deposition of metals on plastic components. The parts are first produced by injection molding, for example from butadiene-containing copolymers such as ABS or ABS / PC. After the injection molding process, the components are chemically pretreated to then autoclatically on them a first thin metal layer, usually a thin nickel or copper layer, deposit. In the further electroplating process, further metal layers are then deposited electrolytically, until finally the electroplating process is finished, usually with a deposited chromium layer.

For all surfaces used, in addition to the high aesthetic standards, there must also be a high resistance to mechanical damage as well as a high level of media resistance in order to meet the later requirements of automotive exterior and interior design.

In addition to all these requirements, however, there is always the desire for more individuality, for design-technical freedom as well as color and structural design of the surfaces. Particularly in the case of metallic surfaces such as galvanic coating, the automotive industry often wishes color flexibility, but has hitherto been severely restricted in this presentation.

The conventional electrodeposited surface finishes and colors usually range from high gloss to various mattness, through to modified electrolytes and processes, to slightly anthracite and brownish shades.

Optical and haptic metallic and colored surfaces are usually possible only through costly additional coatings or possibly additional coating on the metal deposition, the adhesion of the coating layers or the coating on the chromium layer must always be considered critical and massively limited the visual and haptic appearance of the base surface becomes.

To represent colored metallic surfaces, for example, at great expense, a combination of paint, vapor deposition such. As a PVD coating and a tinted, so weakly pigmented Lacquer are applied. Such a technology is used in the DE 102 33 120 A1 described. It is also possible to deposit the deposited metal layers directly on special metal alloys in color on the substrate. In the EP 2 369 032 A1 will describe such an approach. However, a primer for adhesion promotion as well as a downstream, but then clearcoat, is also necessary. However, the color spectrum is limited and the haptic sensation is reduced by the lacquer layer.

The invention aims to remedy this situation. The invention therefore describes a component produced in plastic injection molding with a chemical and galvanic pretreatment and at least one galvanic metal deposition and a subsequent, preferably electrodeposited, aluminum coating, with which in a subsequent anodizing process a high-quality, corrosion-resistant and optional inked decorative metal layer can be formed ,

This problem is solved according to the technical description given in claim 1 and following.

For this purpose, the components to be coated are first produced in the plastic injection molding process from a galvanisable plastic, preferably from a butadiene-containing copolymer such as ABS or ABS / PC. After the injection molding process, the components are chemically pretreated in a conventional electroplating process to subsequently autocatalytically deposit first thin metal layers, usually a thin nickel or copper layer, on this machined surface. In the further electroplating process, at least one metal layer is then deposited electrolytically on which aluminum, preferably electrolytically, is deposited.

In one of the chemical pretreatment following galvanic process step, an aluminum is preferably deposited, which oxidizes in a downstream anodization process to an aluminum oxide and optionally can be colored.

The aluminum is also electrodeposited from electrolytes or from aluminum salts in organic solutions as well as optionally by ionic liquids.

The method according to the invention can thus according to the method form a corrosion-stable, optionally colored and decorative metallic surface coating on plastic components.

The described anodization process uses, like the previously described galvanic process of plastic electroplating, in which the oxidation of the aluminum to aluminum (III) oxide is usually carried out under direct current at the anode. The converted aluminum oxide layer is highly resistant to corrosion and has a high optical appearance.

Before the anodizing process, the aluminum-coated components are usually degreased and pickled to remove impurities, deposits and possibly formed oxide layers.

After anodizing, the aluminum-coated component can be immersed in hot dye solution and then rinsed. When dyeing by this method, the dye molecules accumulate predominantly in the upper regions of the pores of the anodized layer and enter into bonds with the oxide layer.

Using inorganic dyes, staining of the oxidized aluminum layers can also be performed. For this purpose, the component is neutralized after anodizing, rinsed and colored in color baths with metal salt solutions. The ions of the solution accumulate in the pores of the anodizing layer and become a solid.

Another possibility of dyeing describes the electrolytic Colinalverfahren, which is carried out with AC voltage. The electrolyte contains a coloring metal salt. The metal ions penetrate deeply into the pores of the layer. The pores, which are partly filled with metal, now cause a lightfast color due to their absorption and scattering effects. Many different shades are achievable.

Special attractive optical results are obtained in the so-called interference dyeing, in which, in contrast to the previous dyeing technologies, the color of the aluminum is not generated by embedded foreign ions, but by an interference within the aluminum oxide layer. In this case, light appears on thin layers of optically transparent materials such. As an oil film on water or as in soap bubbles is reflected, often colored. This color effect is also referred to as iridescent colors as a result of interference. Depending on the layer thickness of the oxide layer and the associated light extinction, different colors (eg blue, green, gray or red) can be reproducibly displayed.

To prevent the accumulation of corrosive substances and to permanently seal the paint, the pores must be compacted. The anodized and possibly colored aluminum is in a final processing step in demineralized water by simple cooking.

Other developments and refinements of the invention are specified in the remaining subclaims. An embodiment of the invention is illustrated in the drawings and will be described in detail below. Show it:

1 the flow chart of the method according to the invention

For this purpose, the components to be coated are first produced in the plastic injection molding process (a) from a galvanisable plastic, preferably from a butadiene-containing copolymer such as ABS or ABS / PC. After the injection molding process, the components are chemically pretreated in a conventional plastic electroplating process (b) in order to subsequently autocaltically deposit a first thin metal layer on this machined surface (c). In the further electroplating process, at least one metal layer is then applied electrolytically (d) or aluminum is deposited directly in a further galvanic process step (e), which is oxidized to an aluminum oxide in a subsequent anodization process (f) and optionally dyed (g). ,

The inventive method is thus according to the described process steps capable of corrosion-resistant and optionally colored metallic coated decorative plastic components provide (h).

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10233120 A1 [0011]
• EP 2369032 A1 [0011]

Claims (6)

Corrosion-resistant and optionally color-coated metallic decorative plastic components (h) with a chemical pretreatment (b) and deposition of a first conductive metal layer (c) and subsequent electrodeposition of an aluminum (e), wherein the deposited aluminum surface oxidized in a subsequent anodizing process become (f). Component according to claim 1, characterized in that the chemical pretreatment (b) according to a conventional plastic electroplating with the processes pickling with oxidative metal salt solutions for roughening the surface, activating with metal nuclei, z. As palladium and an autocatalytically occurring chemical metallization (c) to form a first conductive layer of copper, nickel or other metal is performed. A component according to claim 1, characterized in that the chemical pretreatment (b) is carried out according to modified mechanical and chemical roughening, swelling and pickling technologies and other technologies for providing a first conductive metal layer adhesion mechanism. Component according to one or more of the preceding claims, characterized in that on the derat pre-treated components in a subsequent first electrolytic electroplating process (d) at least one metal layer is deposited on which in a further, preferably also galvanic process step aluminum is deposited (e). Component according to one or more of the preceding claims, characterized in that is deposited directly on the derat pre-treated components in an electrolytic electroplating process, aluminum (e). Component according to one or more of the preceding claims, characterized in that in a downstream anodization process, the deposited aluminum is oxidized to an aluminum oxide (f) and optionally dyed (g).

Images