DE102010054837A1 - Decorating, labeling and/or tagging component surfaces, comprises applying coloring layer on component surface and curing, applying clear coat layer over coloring layer and curing clear coat, and modifying selected area of coloring layer - Google Patents

Abstract

Decorating, labeling and/or tagging component surfaces comprises (a) applying at least one coloring layer on the component surface and curing at least one layer, (b) applying a clear coat layer over coloring layer and curing clear coat layer, (c) modifying at least one selected area of coloring layer by irradiating with laser radiation, in which a contrast is formed between selected area of coloring layer and the unmodified coloring layer. The clear coating layer is optically and haptically unmodified after modification of selected area of coloring layer, by exposing to laser radiation. Decorating, labeling and/or tagging component surfaces comprises (a) applying at least one coloring layer on the component surface and curing at least one layer, (b) applying a clear coat layer over at least one coloring layer and curing the clear coat layer, (c) modifying at least one selected area of at least one coloring layer by irradiating with laser radiation, in which a contrast is formed between at least one selected area of at least one coloring layer and the unmodified coloring layer. The clear coating layer is optically and haptically unmodified, after the modification of at least one selected area of at least one coloring layer, by exposing to laser radiation. An independent claim is also included for a component comprising at least one coloring layer coated on the component surface and an overlying clear coat layer, in which a contrast is formed between at least one selected area of the coloring layer modified by laser irradiation and the unmodified area of the coloring layer, where the clear coat is optically and haptically unmodified.

Description

The present invention relates to a method for decorating, labeling and / or marking component surfaces with the features of the preamble of claim 1.

Surfaces can be individually labeled, designed or finished by laser beam processing, whereby the surface of a workpiece or a component is changed by the laser radiation and in this way inscriptions, circuit diagrams or individual ornaments are introduced.

The surfaces can be changed in different ways. Thus, for example, in a multi-layer system, layers can be removed, whereby core layers are exposed that have a contrast to the abraded layer, so that after the corresponding processing, a marking or a label can be seen. The disadvantage of such a method is that the surface of such a treated workpiece or component is uneven after the treatment and has a tactile surface roughness. This disadvantage can be remedied by an additional subsequent lacquer application, which, however, is associated with a corresponding additional effort and, moreover, usually results in an optically turbulent surface.

There are other methods in which coloring pigments in the surface are changed by laser absorption, forming a contrast with the unaltered part of the surface. Another possibility of marking, which is particularly suitable for plastic components, is to carbonize the surface precisely by means of laser radiation. The resulting carbon black particles cause blackening of the plastic. The reverse effect can be achieved by melting and foaming the surface, creating gas bubbles that diffuse the incident light so that these areas appear brighter to the viewer than the environment.

In the EP 0 413 664 B1 describes a process for the laser marking of plastic objects, wherein the articles to be inscribed contain a radiation-sensitive, causing a change in light reflection additive and exposed to a laser with pulsed light so that at the irradiated areas of the objects a visual effect mark is formed without the surface the labeled objects are visibly damaged by the eye. In this case, molybdenum disulfide is used as additive.

The DE 10 2006 029 941 A1 describes a method of indirectly marking transparent materials with a laser, wherein the laser beam is directed through the transparency material onto an absorbing substrate, wherein the transparent material is preferably glass. As the substrate, a metal or a semi-metal is used, which is arranged in direct contact or at a constant distance from the surface of the transparent material. The focused laser beam produces an energy density that results in the evaporation of substrate particles to form a vapor jet that condenses on the side of the transparent material facing the marking material. Depending on the level of energy density, either a label can be formed by adhering substrate particles or by removing particles of the transparent material. An inscription by removal of material takes place when the energy density is so high that the substrate particles are heated to a temperature which leads to the surface of the transparent material to additional local material stresses with cracking or local melting.

In the DE 10 2007 034 636 A1 describes a laser-sensitive label with a carrier layer of polyolefin, wherein the carrier layer contains an additive which shows a color change under laser irradiation. In a particularly preferred embodiment of the label, a transparent laminate layer made of a plastic film is arranged on the carrier layer.

The known methods of laser decoration of component surfaces usually have the disadvantage that the surface quality is affected by the treatment.

The object of the present invention is to provide a method for decorating, labeling and / or marking component surfaces or workpiece surfaces that has advantages over the prior art methods.

The object of the invention is also to provide the corresponding laser-marked, marked and / or decorated components available.

The object is achieved by a method for decorating, labeling and / or marking of component surfaces, wherein in a first step at least one coloring layer is applied to the component surface, which is then subsequently cured. In a second step, a clearcoat is applied to the at least one coloring layer and then likewise cured. Thereafter, at least one selected region of the at least one changed coloring layer by irradiation with laser radiation, wherein between the at least one selected region of the at least one coloring layer and the unchanged coloring layer a contrast is formed. Despite the laser irradiation, the clearcoat layer is optically and haptically unchanged and intact after changing the at least one selected region of the at least one colorant layer.

For coating the component surface, the at least one coloring layer is preferably applied with a layer thickness of 15 .mu.m, while the clearcoat layer is preferably applied over the coloring layer with a layer thickness of .ltoreq.50 .mu.m. In this case, a clearcoat based on acrylate, which preferably comprises n-butyl acetate as the solvent, is advantageously used as the clearcoat.

The present invention also provides a component produced by the process according to the invention having at least one colorant layer applied to the component surface and a clearcoat layer disposed thereover, wherein the colorant layer is changeable without detectable optical or haptic change of the clearcoat layer by means of irradiation with laser radiation. After changing the at least one selected area of the coloring layer, a contrast is preferably formed to the unaltered areas of the coloring layer, wherein the changes settle out sharply from the remaining coloring layer.

According to a preferred embodiment of the present invention, a plurality of different coloring layers can be applied one above the other to the component, whereby a multicolored decoration can be formed under the action of laser radiation by changing at least one selected area of at least one of the coloring layers. When applying several different coloring layers to the surface of the component, specific layers can then be selectively removed by laser irradiation, so that in the end a multicolored decoration is created.

A further advantageous embodiment of the present invention provides that the at least one coloring layer comprises metal particles as coloring pigments. The metal particles are vaporized and removed under the action of the laser radiation and it comes to the component surface or another layer lying below the coloring layer to light, which then forms a contrast to the coloring layer, so that a high-contrast, edge-sharp decoration without visible or palpable surface change of the Clear lacquer is created.

In this context, it should be noted that experiments have shown that, especially in use. color-containing layers containing metal particles, the addition of an elastifier or plasticizer in the clearcoat has a positive effect on the behavior of the clearcoat layer during the irradiation with laser beams. Thus, in these cases, intact surfaces were obtained even with relatively thick coloring layers or clearcoat layers after the laser irradiation. This may be due to the fact that, at least for a short time under the action of laser radiation, the clearcoat layer may need to have some gas permeability to allow vaporized metal to escape, gas permeability may be facilitated by the presence of an elastomer or the reversibility of gas permeability possibly required changes of the clearcoat film could be increased.

Depending on which surface requirements are met, the clearcoat used may be a matt or glossy, optionally scratch-resistant, clearcoat which, if possible, may also be resistant to chemicals.

The main body for the component may be made of metal or plastic, so that the process overall results in a wide range of applications, the components according to the invention in particular in the field of safety technology for the provision of clear lacquer protected decors and / or labels, in the automotive industry to provide Exterior or interior components with high-quality decorative surfaces and used in medical technology to provide easy-to-clean permanently marked surfaces.

In the following, the present invention will be explained in more detail by way of examples.

example 1

It was primed components made of thermoplastic material with a metallic paint containing color pigments decorative lacquer, wherein the decorative lacquer was applied with a layer thickness of about 10 microns on the plastic surface. The decorative paint was a paint comprising Al particles, known in the art as "galvanosilver". After the thermal curing of the coloring layer (decorative lacquer), a ca. 30 μm thick clearcoat was applied to the decorative lacquer, which was thermally cured. The clearcoat was a product of Ritzi Lackiertechnik GmbH, D-78609 Tuningen with the trade name translas 01 used. This is an acrylate-based clearcoat comprising n-butyl acetate.

The component pretreated in this way was subsequently processed by means of laser radiation, a laser from Trumpf Laser Marking Systems AG, CH-7214 Grüsch with the designation VMC5 being used. The system operates at a wavelength of 1064 nm and the laser-active medium Nd: YV0 ₄ .

In this treatment, the decorative layer containing the metal particles is removed and the component surface appears, which forms a contrast to the intact coloring layer. The varnish covering the coloring layer remains intact during this operation and neither visual nor tactile changes in the surface of the varnish are discernible. The decor thus obtained is characterized by an extraordinary edge sharpness.

Example 2

Color-coated metal components were coated with an acrylate-based clearcoat. The clearcoat used was a product from Nano-X GmbH, D-66130 Saarbrücken with the product name VB KR 3812. The layer thickness of the color coat was 8 μm, while the layer thickness of the clearcoat layer had 25 μm. As in Example 1, the laser irradiation is carried out with a laser VMC5 Trumpf. Under the influence of the laser beam, the color coat was carbonized at selected areas and the resulting soot particles gave these areas a black color, which stands in contrast to the original color. Also in this case, the clear coat has survived the laser irradiation without visible or tactile changes, while on the surface of the component a sharp-edged decor can be seen.

Example 3

A component made of thermoplastic material was coated with a decorative paint containing a metal particle as coloring pigments with a layer thickness of about 8 microns. The decorative lacquer used was "Galvanosilber" containing Al metal particles, which was thermally cured. The subsequently applied and cured with UV radiation high-gloss clearcoat was a product of Lackfabrik Votteler GmbH & Co. KG, 70825 Korntal-Münchingen, which is sold under the trade name Cry-Lux-Lack with the article number 115440180. As in the previous cases, the laser irradiation was performed with a laser VMC5 from Trumpf.

After the laser treatment, no visible or tangible changes can be seen in the clearcoat.

In addition, the so coated and decorated component was subjected to a so-called condensation test at 50 ° C and 98% relative humidity without any deterioration or bursting of the clearcoat was observed. The same component also became a crosshatch test DIN EN ISO 2409 subjected. Again, no dissolving layer particles could be determined, which would have pointed to damage to the clearcoat.

Example 4

Selected areas of a component made of a thermoplastic material were first coated with an 8 μm thick colored lacquer layer. After these areas had hardened, the entire component was coated with a decorative paint (galvanic silver) containing metal particles. The approximately 8 μm thick layer was thermally cured. An approximately 20 μm thick clearcoat film based on acrylate was applied to this coat, using a clearcoat from BASF SE, 67056 Ludwigshafen, designated Laromer PO 9026. The laser treatment was again carried out with the laser system VMC5 from Trumpf. In the areas of the triple coating, the decorative lacquer layer was removed by means of laser radiation, while at the same time the underlying lacquer layer was carbonized, so that in these areas a contour sharp black decor was obtained, while in the only two-layered areas by the laser irradiation only the decorative lacquer is removed and so that the component color itself comes to light, so that in this way a multi-colored decor is obtained.

Also in this case, the finished product, on whose clear coat no visual or haptic changes were detected, a sweat test and a cross hatch test were subjected. In both tests, no defective change in the clearcoat could be determined.

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

• EP 0413664 B1 [0005]
• DE 102006029941 A1 [0006]
• DE 102007034636 A1 [0007]

Cited non-patent literature

• DIN EN ISO 2409 [0026]

Claims (11)

Method for decorating, labeling and / or marking component surfaces with the following steps: applying at least one coloring layer to the component surface and then curing the at least one layer, applying a clearcoat layer over the at least one coloring layer and then curing the clearcoat layer, changing at least one selected area of the at least one coloring layer by irradiation with laser radiation, whereby a contrast is formed between the at least one selected area of the at least one coloring layer and the unchanged coloring layer, characterized in that the clear lacquer layer after changing the at least one selected area the at least one coloring layer is optically and haptically unchanged under the action of laser radiation. A method according to claim 1, characterized in that the curing of the clearcoat layer takes place thermally and / or with the aid of UV radiation. A method according to claim 1 or 2, characterized in that the at least one coloring layer with a layer thickness of ≤ 15 microns and the clearcoat layer is applied with a layer thickness of ≤ 50 microns. Method according to one of claims 1 to 3, characterized in that a clearcoat based on acrylate is used. Method according to one of claims 1 to 4, characterized in that the clearcoat comprises n-butyl acetate. A component having at least one coloring layer applied to the component surface and a clearcoat layer applied thereover, wherein a contrast to the unchanged part of the coloring layer is formed between at least one selected area of the coloring layer modified by laser irradiation, characterized in that no optical or haptic layer is present in the clearcoat layer Changes are recognizable. Component according to claim 6, characterized in that the changes of the at least one selected region of the coloring layer are sharp edges. Component according to claim 6 or 7, characterized in that the component has a plurality of different coloring layers applied to one another, a multicolored decoration being formed by the action of laser radiation by changing at least one selected area of the coloring layers. Component according to one of claims 6 to 8, characterized in that the at least one coloring layer comprises metal particles as coloring pigments. Component according to one of claims 6 to 9, characterized in that the base body of the component consists of metal or plastic. Use of components according to one of claims 6 to 10 In the field of security technology for the provision of clear lacquer-protected decors and / or inscriptions, - In the automotive industry for the provision of exterior or interior components with high-quality decorative surfaces and - In medical technology to provide easy to clean, permanently marked surfaces.