EP1304235A1 - Process for producing a structured varnish layer with a transfer film - Google Patents

Abstract

To form a structured lacquer layer (14) on a carrier film (10), as a release carrier, the lacquer is structured by an embossing cylinder. The lacquer is composed of two components with different setting characteristics. The coated film can be covered by a decorative colored layer (12). <??>The prepared film is inserted into the mold of an injection molding machine, for the injected plastics to bear against its rear surface, to give the required surface appearance to the molding. One lacquer component is set by heat, and the other component is hardened by ultra violet light.

Description

The invention relates to a method for generating a structured Paint layer on an object using a carrier film with "release" property.

Products and objects of all kinds, especially also plastic products with a layer of varnish, to certain properties of the surface of the product improve, e.g. B. the optical, aesthetic, mechanical, or haptic properties.

For the transfer of lacquer layers and layers of paint is the So-called "release" technique known (z. B. EP 0 573 676 A1). As flat supports with "release" properties come in particular certain papers and plastic films considered in the prior art, designed or prepared on their surface are that applied layers of paint and possibly Layers of paint like a "peeling off" like a decal are transferable to a substrate.

It is a method of making a decorated injection molded part have been developed (cf. unpublished European patent application, application no .: 00 116 183.5), in which a thermoformable film with "release" property and one paint decor layer applied thereon in an injection mold in front of a cavity, the shape of which is to be manufactured Molded part is arranged, then the film is back-injected with a plastic and the so produced Molded part and the film are separated from each other, whereby the paint decor layer adheres to the molded part from the film. A layer of varnish is preferred on the film under the Color decor layer applied that matches the color decor layer detaches from the film. Most ultimately produced, coated The colored decorative layer lies directly on the molded part and the paint layer on the outside.

The present invention is based on the object Provide method with which a layer of paint on a Product can be structured. Under "structurability" is here a fine structure in the outer surface of the lacquer layer understand, such as the structure of leather or wood etc. The generated surface structure can be optically aesthetic and / or be technical-functional. For example, the goal of structuring be a regular geometric shape for z. B. certain Light reflections, or it can also be functional Structures are sought, such as a certain feel (grip), z. B. a so-called "soft touch" (soft handle) or like.

• die Träger-Folie entsprechend der zu erzeugenden Struktur geprägt wird,
• eine Lackschicht auf die geprägte Träger-Folie aufgetragen wird und die geprägte Struktur aufnimmt, und
• die so strukturierte Lackschicht von der Träger-Folie auf den Gegenstand übertragen wird.

In its most general embodiment, the method according to the invention for producing a structured lacquer layer on an object provides that

• the carrier film is embossed in accordance with the structure to be produced,
• a layer of lacquer is applied to the embossed carrier film and picks up the embossed structure, and
• the lacquer layer structured in this way is transferred from the carrier film to the object.

The present invention has shown that by embossing the Carrier film itself a layer of varnish that is on the carrier film is applied, are shaped in their surface structure can.

If necessary, a colored decorative layer can be applied over the lacquer layer are applied in a manner known per se, e.g. with "release" technology.

This creates a product from a carrier film with it applied varnish layer, which structures in its surface and over it a color decor. This product is as such tradable and can be processed to a Object with a layer of varnish and possibly one To send colored decor, whereby the lacquer layer prefers over the Color decor on the object.

According to a preferred embodiment of the invention, that a paint is used for the paint layer, the has at least a first paint component which with a first hardening process is hardenable, and a second lacquer component, which is curable with a second hardening process, wherein the first paint component with the first hardening process is hardened so far that the lacquer layer is structurable, and the second paint component after the transmission is hardened with the second hardening process.

When using a two-component lacquer, this is preferred called first hardening process a radiation hardening, such as a UV radiation curing and the second curing process is a thermal hardening. The second paint component can be chemical be set so that the thermal curing with the Time even at slightly elevated temperatures and even even at room temperatures (over several hours or Days).

The invention is preferably used in an injection mold realizes that the carrier film with the embossed structure, the lacquer layer above and the color decor if necessary positioned in the injection mold and there with plastic is injected.

This back injection creates pressure and the paint layer is pressed against the embossed carrier film. The takes Paint layer the surface structure of the carrier film on (on), i.e. the paint layer itself is structured in exactly the way how the carrier film was previously embossed. So that The first layer is the layer of lacquer that takes up the embossing under pressure Component previously hardened according to the first hardening process that it picks up the structure. Thereby is highest conducive to the fact that the second paint component has not yet hardened is, at least not fully cured, so the lacquer layer overall still a sufficient softness and Has adaptability to be processed, especially with regard to the structural adaptation to the three-dimensional Structure of the paint to be decorated Object. The system consists of carrier film and lacquer layer So that the lacquer layer is sufficiently malleable to the Embossing stable, but still sufficient overall is deformable to adapt to any very complicated three-dimensional structure of the one to be manufactured To enable the object.

The second paint component is then cured, the Hardening both during the injection molding process itself or also later preferred to set by itself.

The invention also relates to a carrier film with a lacquer layer and optionally a color decor layer according to the representation above.

As mentioned, the invention is preferably in Injection molding technology is realized, so that in the described Wisely produced film with a textured embossed lacquer layer and optionally color decor layer in an injection mold arranged in a cavity, the shape of which is to be manufactured Molded part (product). After the spraying process and the transfer of the embossed structure described above into the lacquer layer, the injection mold is opened and the Carrier film with "release" property can be peeled off and the injection molded part produced is with a color decor and a structured layer of lacquer over the color decor.

The quantitative ratio (mixing ratio) of the various Paint components are based on the requirements of the ultimately produced structured lacquer layer especially mechanical requirements such as abrasion resistance, Scratch resistance, hardness, elasticity etc. When used two paint components, one of which is thermally curable and the other is UV curable, there are mixing ratios (in percentages by weight) of thermally curable lacquer UV-curable varnish in the range from 20:80 to 60:40 has proven its worth according to the requirements.

The thermal curing of the paint can, for. B. at temperatures from 60 to 80 ° C. It is also possible to use a thermal to choose lacquer that can be hardened at room temperature (e.g. in a few days).

The method enables in particular the generation of a structured lacquer layer with very high abrasion resistance (more than 10 times better than in the prior art).

The described stamping technique for the surface enables finest embossed structures that are fully preserved during injection molding stay d. H. the explosiveness and the geometric resolution of the Fine structures are obtained, e.g. B. down to fine structures in the range of 10 to 15 µm, depending on the coating thickness. Prefers coating thicknesses in the range of 5 to 30 µm are used and the embossed structures (in terms of depth and dimension of the structures in the surface plane) can also change are in this area. In other words, the process enables extremely high geometric resolution (fine structure) the embossed surface structures.

The "release" film used is thermoformable in the sense that they are strong by means of a pressure difference or injected, hot plastic mass is deformable. For the slide can engineering thermoplastics are used, e.g. PET, polypropylene, Polyethylene, or polyester with PVA coating.

The film preferably contains a high proportion of so-called plasticizers. It has been shown that the addition of plasticizers does not affect the temperature resistance of the "release" film. Foils with a temperature resistance are used up to 400 ° C.

According to a preferred embodiment of the invention, for The color decor uses a color that is injected into the back Diffuse plastic or paint. The usage such a diffusible color in the decor has the advantage that the decoration in the end product has a very high brilliance having.

Both the lacquer layer and the color decor layer can also be used the release technique can be applied to the film.

Fig. 1A

eine Folie mit darauf aufgetragener Lackschicht und einen Prägezylinder;

Fig. 1B

eine geprägte Folie mit Lackschicht und darauf aufgetragener Farbdekorschicht;

Fig. 2

schematisch eine Vorrichtung, mit der ein dekoriertes und strukturiert lackiertes Spritzgußformteil herstellbar ist;

Fig. 3

einen Ausschnitt von Fig. 2 in vergrößertem Maßstab; und

Fig. 4

ein fertiges Spritzgußformteil mit Farbdekorschicht und Lackschicht, die in der Oberfläche strukturiert ist.

Details of the invention are described in more detail below with reference to the drawing. It shows:

Fig. 1A

a film with a layer of lacquer applied thereon and an embossing cylinder;

Figure 1B

an embossed film with a layer of lacquer and a layer of colored decor applied to it;

Fig. 2

schematically shows a device with which a decorated and structured lacquered injection molded part can be produced;

Fig. 3

a section of Figure 2 on an enlarged scale. and

Fig. 4

a finished injection molded part with colored decor layer and lacquer layer, which is structured in the surface.

According to Figure 1A, a carrier film 10 made of z. B. PET, polypropylene, Polyethylene or a polyester with PVA coating, by means of an embossing cylinder Z, which has a desired structure S, embossed. Here is the carrier film 10 not yet provided with a layer of lacquer. It understands that the film is suitable for embossing on the underside is supported. Through the embossing by means of the cylinder Z the structure S is stamped into the carrier film 10, cf. the enlarged view of a section in Fig. 1A, right.

Then a lacquer layer 14 is applied to the embossed carrier film applied, e.g. with "release" technology. The paint layer is preferred, in deviation from Fig. 1A, 1B, on the embossed Side of the carrier film 10 applied. The latter will above all then recommended if very fine structures in the surface of the paint are to be generated. With relatively large areas Structures such as Wood or the like, the lacquer layer can also applied to the non-embossed side of the carrier film become.

The lacquer layer 14 contains at least two different ones Paint components, on the one hand a thermally curable paint component and on the other hand a coating component curable with UV radiation. The mixing ratio of thermally curable paint to UV-curable lacquer is (in weight percent) 20:30 to 70:30, depending on the requirements of the ultimately to be manufactured Paint layer.

After being applied to the carrier film, it becomes a lacquer component hardened to the extent desired is structurable, i.e. the embossed structure is suitable to take over from the film under pressure. The other paint component remains unhardened, so that the paint layer does not become too brittle.

According to FIG. 1B, a colored decorative layer can be applied over the lacquer layer 12 are applied, e.g. with the mentioned "release" technique.

The film 10 preferably contains a high proportion of plasticizers, without losing their temperature resistance up to 400 ° C. In particular, a plasticizer (plasticyzer) proven from 5 to 20 percent by weight in the film, each after application. The thickness of the film 10 is 5 to 50 microns.

FIG. 2 shows a device with which the method can be carried out is. An injection mold known as such has two injection molds 16, 18, which are movable relative to each other are. Between the forms 16, 18 is in a known manner a cavity 20 is formed and liquid plastic is through a channel 22 in the cavity 20 corresponding to the arrow 44 injected. This is done with high pressure and high temperatures, in injection molding technology known per se.

The embossed film 10 described above, with a layer of lacquer 14 and a color decor layer 12 is provided thereon, is unrolled from a roll 26. Are the injection molds 16, 18 spaced apart (not shown), the Foil through the tool, that is to say from top to bottom in FIG. 2, lead and on the bottom to another roll 28 again roll up. The roller 28 receives the film 10, of the the color decor 12 and the paint 14 have been removed in the process are, as described in more detail below.

The film 10 rolled off the roll 26 with the color decoration 12 and the lacquer 14 is positioned in the injection mold 16, 18, as shown in Figure 2. The layers take the Figure 3 shows an arrangement shown. The film 10 is therefore during the injection molding process directly on the cavity 16a of the injection mold 16 on. The lacquer layer 14 and over the lacquer layer 14 the color decor layer 12. The injected hot plastic material comes directly with the color decor layer 12 in contact and connects to it. By the Add strong plasticizers in high concentration in the The material of the film 10 is such that the film 10 (and the structured lacquer layer on it as well as the Color decor layer) also on strong 3-dimensional deformations can adapt to the cavity 16a. The film 10 presses against the cavity 16a under pressure and temperature of the injected Plastic, with a temperature range of 150 ° C to 300 ° C is preferred.

It has been shown that the embossing described above in the Carrier film fully into the paint layer during injection molding transmits, ie "pushes through" and thus on the outside (in Figure 2 left) is preserved.

Due to the "release" property of the film 10, this can be the back injection in a simple way and on the lower roll 28 are wound.

Figure 4 shows the resulting molded part 30 with a color decorative layer 12 and above a lacquer layer 14, the Paint layer 14 on its outer surface in the manner described above Is structured (shaped), e.g. B. in Art of leather or wood.

If a suitable, diffusible color is used, diffuses these at the given temperatures directly in the plastic of the molded part 30.

Claims (10)

Method for producing a structured lacquer layer on an object (30) using a carrier film (10) with "release" property,
characterized in that the carrier film (10) is embossed in accordance with the structure to be produced, a lacquer layer (14) is applied to the embossed carrier film and picks up the embossed structure, and the lacquer layer (14) structured in this way is transferred from the carrier film (10) to the object (30). Method according to claim 1,
characterized in that a color decoration (12) is applied to the lacquer layer (14). Method according to one of claims 1 or 2,
characterized in that a lacquer is used for the lacquer layer (14) which has at least a first lacquer component which can be hardened by a first hardening method, and a second lacquer component which can be hardened by a second hardening method, the prior to the absorption of the structure the first lacquer component is hardened with the first hardening process to such an extent that the lacquer layer can be structured, and the second lacquer component is hardened after the transfer with the second hardening process. Method according to claim 3,
characterized in that the first hardening process is radiation hardening, in particular with UV radiation. Method according to one of claims 3 or 4,
characterized in that the second hardening process is thermal hardening. Method according to one of the preceding claims,
characterized in that the carrier film (10) with the lacquer layer (14) and optionally the color decoration (12) is back-injected in an injection mold (16, 18). Method according to claim 6,
characterized in that the second lacquer component is cured during or after the back injection. Method according to one of claims 3 to 7,
characterized in that the quantitative ratio of the thermally curable lacquer component to the radiation-curable lacquer component is in the range from 20:80 to 60:40. Carrier film (10) with lacquer layer (14), the corresponding a surface structure to be created is shaped. Carrier film according to claim 9, with a color decorative layer (12).

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