EP0687580B1 - Surface coating process for imitating the appearance of natural wood - Google Patents

Abstract

Surface coating processes for producing an imitation root timber effect comprise (A) (1) applying a layer of filler with a colour which determines the base shade of the final effect; (2) air-drying the filler coat; (3) preparing a soln. of scumble paste in water; (4) applying this soln. to the filler coat; (5) trickling or spotting alcohol, spirit, isopropanol, acetone, EtOAc, etc., onto the still-wet scumble coat to form the root timber pattern; (6) drying rapidly; (7) applying and drying opt. coloured clearcoat(s); and (8) applying clear topcoat(s); (B) (a) performing stages (1)-(4) as above; (b)(5) sprinkling salt grains on the still-wet scumble to form the pattern; and (c) performing stages (6)-(8) as above; (C) to produce the effect on glass, (1) cleaning and degreasing a glass plate, etc.; (2) coating with an adhesive clear varnish or transparent adhesive and drying this; (3) applying a scumble coat as in (A) and (B) stage (4); (4) forming the pattern as in (A)(5) and drying this; (5) coating with an acrylic scumble coloured to match the shade of the first scumble (3); (6) applying a primer paint coloured to match the ground colour of the imitation root timber layer; and (7) applying a coat(s) of protective varnish.

Description

The invention relates to a surface coating process to achieve a root wood imitation effect.

For environmental and ecological reasons, the use of natural root woods, for example in vehicle construction, always more restricted.

Regardless of this, there is a great need for an optical attractive design of the surfaces of plastic, Molded, injection molded or cast parts.

It has therefore already been proposed to use single-sided adhesive films made of plastic with imitation burl wood and then these foils on the surface of the optically refined Glue plastic or metal parts. trouble However, this occurs when curves, corners and Edges of intricately shaped plastic parts coated should be. In addition, such a procedure requires an extremely careful treatment of the adhesive film, combined with a high level of manual dexterity, so that automated production of complex shaped parts is almost impossible.

From US-A-5,122,395 is a method for surface treatment so well known that a burl wood structure can be formed by first a solution of water and dye is applied to the surface to be treated is followed by a organic liquid is applied selectively. This organic liquid can be methyl, ethyl, propyl, isopropanol or something like that.

In the process of producing colored patterns on documents according to DE-PS 833 472 is first on the document aqueous layer of paint applied to blowing agents such as Alcohol or acetone on the not yet dried paint layer tap on. If necessary, this should be done several times with different Dyes are added. Following that, the Pad to be heated. Because of this warming it happens evaporation of the propellant, the base, which is to be coated in a tilting or circular motion is move. For heating a glass plate to be coated is specifically stated that this warming takes place so that the driving effect of the applied alcohol is strengthened, whereby the pigments of the primary color layer in Movement should come so that dye accumulations in train changing strength. But such an effect applies to avoid when achieving root wood imitation coatings.

JP-A-4-260475 discloses to form a pattern first the provision of an underlayer on a given one Surface. An adhesion promoter is then placed on this lower layer, which may contain pigments applied. In one next step is a liquid with a low Surface tension is applied to the adhesive layer. The liquid obviously interacts with the Pigments containing adhesive layer, so that a Light and shadow structure, i.e. a corresponding pattern trains.

It is therefore an object of the invention, taking into account the The above-described prior art is a further developed Surface coating process to achieve a Specify root wood imitation effect, which is also complicated structured and shaped surfaces reproducibly coated can be, and that a rational, automatable Manufacturing allowed.

The object of the invention is achieved with a method as defined in claim 1, wherein the Expedient refinements and developments represent.

According to the invention, after applying a the fundamental tone of the filler layer determining later imitation layer under short Flash off a dough glaze dissolved in water Spray or brush applied.

Then on the not yet dried dough glaze layer Dripping on or spraying on alcohol, isopropanol, Acetone, ethyl acetate or the like or an application of Salt or coarse salt grains made. In this step a grain that is typical of burl wood develops, which is then quickly dried into a paintable Condition is transferred. Before applying a clear lacquer top coat can then expediently at least one Colored clear coat can be applied, the coloring is selected according to the respective natural wood color and the plastic character and the special structure of the Root wood emphasizes more.

The invention will now be based on several exemplary embodiments are explained in more detail.

In a first embodiment, a plastic material assumed that which is initially briefly on the surface side is dissolved and, if necessary, provided with a primer. After flashing, a filler is applied, with the Color of the fountain pen is the basic tone of the later wood imitation certainly. In the first embodiment, the root of the Filler beige.

In parallel, a brown, initially pasty dough glaze with very Much water mixed so thin that there is a throughput time of 12-18 sec. in a DIN cup. The dough glaze preparation is essential for the later imitation root wood pattern. The prepared dough glaze is then on the Filler layer sprayed on or spread on.

Before the dough glaze layer has dried, methylated spirit is now used injected loosely and irregularly or instilled. The same applies to the application of individual drops Alcohol possible with a pipette.

It has been shown that instead of alcohol or alcohol also sprinkled with petrol, isopropanol, acetone, ethyl acetate or the like can be.

As a result of the instillation mentioned, there is a displacement of components of the dough glaze instead, as a result Draw typical root wood structure pictures.

This structure formation is due to the amount of applied Spirit or the like and the degree of drying of the dough glaze layer controllable.

The applied layers are then dried for example in a continuous furnace at 60 ° C and approx. 2 minutes. It has proven to be advantageous in that this Drying process carried out quickly and without interruptions becomes.

After drying, a clear coat, for example a One-component clear coat, provided with coloring, i.e. tinted applied to further improve the imitation wood character to achieve. According to the first embodiment becomes a brown dough glaze on the beige filler mentioned applied and the clear coat layer tinted brown.

It has been shown that a gray tint is a cold one Burr wood tone, a beige to brown tint a warm one Wood tone results.

Likewise, any color, for example pink, rose red, light to dark blue, yellow, orange or nuances of which can be achieved. Is also a metallic, polychrome or opalescent tint successfully tested been.

It is possible to three to three times the colored clear coat to be applied five times for a correspondingly deeper tint. At this Place should be mentioned that the clear coat layers and the later applied top layers, which expediently consist of a two-component acrylic paint for durability of the surface obtained are essential.

The application of the actual top layer or the top layers takes place in a manner known per se, with intermediate sanding if necessary becomes. The result is a quasi glassy coating, which overall makes for an appealing exterior Appearance of such surface treated Leads objects.

At this point it should be mentioned that in addition to plastics other materials, such as metals, in the above described manner can be treated.

In a second embodiment, the background treatment takes place including applying the water diluted Dough glaze in the same way. On the fresh surface, i.e. the dough glaze layer that has not yet dried becomes petrol dosed injected or instilled, which causes a marbled surface results. Then immediately with alcohol or high-proof alcohol another instillation or dosed injection. All other Steps then take place analogously to the first exemplary embodiment.

In this second embodiment there is a special one plastic effect of the imitation wood structure. In general, it is noted that large drops of spirit are large Root roots result. So it can be applied with the amount of Spirit or the like on or in the dough glaze layer the size and / or the distribution of the root wood approaches targeted to be controlled.

In a third embodiment, instead of one in Water-based dough glaze is a water color, for example Magiccolour, spread or varnished. Not yet dried surface prepared in this way then becomes alcohol dripped or with a pipette or other suitable Means injected. In this case, too Wood grain structure.

According to the fourth embodiment, including the Applying the dough glaze layer as in the first embodiment proceed, but instead of alcohol or Like. The not yet dried dough glaze layer with coarse salt is sprinkled.

In this case, too, a finer root wood structure is formed from that in the according to the first embodiment described way is treated further.

All in all, can be used for the formation of the imitation wood pattern or the imitation wood structure that in a water-soluble, especially dough glaze alcohol, gasoline, Isopropanol, acetone, ethyl acetate or the like loose and is sprayed or introduced at irregular intervals.

After a quick drying process, further treatment takes place, that of improving the already existing Structure and achieving adequate durability serves. The method according to the aforementioned exemplary embodiments has been successful on different substrates, for example wood, wood substitutes, metal, Tried and tested plastic, polyester and the like. To be sufficient Adhesion of the individual layers, especially the filler layer To achieve, however, is one on the respective starting materials coordinated basic treatment required.

It should be noted that the application of the dough glaze or Casin colors are very rich, which makes a particularly uneven, visually reminiscent of natural root wood structures Effect is achievable.

Claims (6)

1. Surface coating process for obtaining an imitation rootwood effect, comprising the following steps:

   applying a filler coat, whose colour determines the basic shade of the subsequent imitation;

   flashing off the filler coat;

   preparing a water-dissolved paste glaze which is highly mobile, such that the resulting efflux time in the DIN cup is 10-18 seconds, preferably 12-15 seconds;

   repletely applying the paste glaze solution to the filler coat;

   tricklewisely or spotwisely applying alcohol, spirit, isopropanol, acetone or ethyl acetate or distributedly applying salt grains to the as yet undried paste glaze coat, in order to form the rootwood pattern;

   rapidly and uninterruptedly drying the applied coats in a through-type oven at essentially 60°C in a time of essentially 2 minutes;

   applying at least one colourable clearcoat film and drying it, and

   applying at least one transparent topcoat.
2. Surface coating process according to Claim 1, characterized in that in order to obtain a brownish rootwood structure the colour of the filler coat is beige and in that the coloration of the at least one clearcoat film is beige to brown.
3. Surface coating process according to either of the preceding claims, characterized in that the paste glaze solution is applied by brushing or spraying.
4. Surface coating process according to one of the preceding claims, characterized in that water-soluble casein colours are used instead of paste glaze.
5. Surface coating process according to one of the preceding claims, characterized in that the subsequent coloration and structure of the rootwood imitation is adjustable through the thickness of the paste glaze or casein colour coat.
6. Surface coating process according to Claim 1, characterized in that the paste glaze coat is applied by spraying and, subsequently, the glaze coat is over-brushed in a controlled manner in order to establish different coat thicknesses and to structurally distribute the dissolved constituents in the paste glaze coat, by means of which the appearance of the wood imitation is variable.