EP0993875B1 - Process for colour decorating an object - Google Patents

Description

The invention relates to a method for applying a color decoration on a substrate using a carrier with so-called "Release" properties.

In particular, the following are considered as material for the substrates: Glass, metal, ceramic materials, plastics, wood, Wood materials, textiles and leather.

Carriers with "release" properties are known as such (cf. EP 0 573 676 A1). As a flat carrier with "release" properties certain papers are particularly considered or also plastic films that are designed on their surface or are prepared that applied under certain conditions Layers of paint or varnish in the manner of a "Peeling off" (like a decal) can be transferred to a substrate are. For the present invention come in particular as Carrier with "release" property plastic films into consideration, such as especially polyester films that have a suitable release layer to achieve the "Release" (Abpell) property.

The aforementioned EP 0 573 676 A1 already describes the use a carrier with a "release" property for applying Color decor on a substrate. With this state of the art for this purpose, the color decor on a support "Release" property applied, then on the carrier applied color decor applied a varnish, the varnish then partially networked and then under pressure and / or increased The temperature of the partially cross-linked paint together with the color decoration from the bearer transferred to the substrate to be ultimately decorated in such a way that the paint is under the color decor on the substrate. Finally there is a further crosslinking of the lacquer the substrate.

Should be three-dimensional objects with the "release" technique be decorated in color (being under a colored decoration a homogeneous, monochrome decoration is also to be understood), occur particularly in the area of edges and also at complicated problems regarding molded three-dimensional objects the quality of the decoration.

a) Aufbringen eines Farbdekors auf einen ersten Träger mit "Release"-Eigenschaft,

b) Übertragen des Farbdekors vom ersten Träger mit "Release"-Eigenschaft auf einen zweiten Träger mit "Release"-Eigenschaft, und

c) Übertragen des Farbdekors vom zweiten Träger auf den Gegenstand.

A method with the following steps is known from US Pat. No. 5,537,921:

a) applying a color decoration to a first carrier with a "release" property,

b) transfer of the color decoration from the first carrier with "release" property to a second carrier with "release" property, and

c) transfer of the color decor from the second carrier to the object.

The invention has the goal of color decoration with "release" technology to improve qualitatively.

According to the invention, this is achieved in that after step (b) a layer of lacquer is applied to the color decor Step (c) is applied to the bottom of the article.

It can be provided that on the second Carrier transferred color decor applied paint layer in front of the Transfer of the color decor to the object to be decorated undergoes partial crosslinking.

The invention is based on the knowledge that the color decoration can be improved with "release" technology that at least two different carriers with "release" property are used, the first carrier (process step a) good with the selected printing technique with the color decor is printable, while the second carrier is not necessary which must have good printability, but rather with regard to its mechanical properties is optimal for its purpose according to method step (c), namely the transfer the color decor on the object to be decorated. The second carrier is therefore particularly flexible and / or elastic and can be adhered to well, especially without gaps Edges or other critical areas of an object to be decorated lay.

A carrier material which, for. B. well suited for the first carrier, is a polyester film. As a material for the second carrier, which has particularly good mechanical transmission properties when transferring the main decor has the object to be printed in particular Polyolephins, e.g. B. polyethylene, or polyvinyl chloride films. Polyvinyl alcohol (PVA) films are also suitable, the latter especially for items with special complicated structures. PVA films are particularly suitable for techniques where the color decor on the surface a liquid and the object to be decorated is immersed in the liquid to open the decor to transfer the object (cf. EP 96 117 502.3).

A preferred embodiment of the method according to the invention provides that after step (c) a layer of paint on the color decor is applied. Thereafter, preference is given to the upper one Painted a layer of hot gas. Before that, the layers of paint may be subjected to full hardening, especially with electron beam.

The hot gas is preferably in the form of a so-called "hot gas meter" passed over the top layer of paint, in such a way that the Gas temperature of the hot gas and the relative movement between the hot gas and the article are controlled so that essentially only the top layer of paint is heated effectively. With this preferred development of the invention ensures that the decorated and painted objects have a special depth effect of the color, continue to show good adhesion of the applied Color and varnish layers with each other and on the object given and finally the scratch and abrasion resistance is improved.

Figur 1

einen ersten Träger mit darauf aufgetragenem Farbdekor;

Figur 2

das Ergebnis der Übertragung des Farbdekors vom ersten Träger auf einen zweiten Träger;

Figur 3

die Dekorierung eines Gegenstandes mit einem Träger und einem Farbdekor gemäß Figur 2; und

Figuren 4 - 7

ein weiteres Ausführungsbeispiel einer Dekorierung eines Gegenstandes mit verschiedenen Schritten.

The invention is explained in more detail below with the aid of schematic drawings. It shows or show:

Figure 1

a first carrier with color decor applied thereon;

Figure 2

the result of the transfer of the color decoration from the first carrier to a second carrier;

Figure 3

the decoration of an object with a carrier and a color decor according to Figure 2; and

Figures 4 - 7

a further embodiment of a decoration of an object with different steps.

Figure 1 shows a carrier 10 with "release" properties. The Carrier 10 is a polyester film in the illustrated embodiment. Generally, the carrier 10 has the property of being good with the color decor to be printable, d. H. the carrier takes one Color decor layer on well. However, a polyester film has that Ability to be little elastic and when being around objects not cling to the shape of the object very well to be able to. The color decor layer 12 has dyes that can diffuse in paint (e.g. diffusible disperse dyes).

FIG. 2 shows the result of a method step initially provided, namely the transfer of the color decor 12 from the first Carrier 10 on a second carrier 14. The carrier 14 is made from a material that is less printable than the material of the carrier 10, but for the subsequent decorating process has better properties, especially better adaptable to the shape of a complicated object 16 is. In particular, come as material for the second carrier 14 Consider polyolephins, such as polyethylene. Other materials are mentioned at the beginning.

The thickness of the carrier 14 is chosen to be relatively thick, in this area from 300 to 600 µm. On the first carrier 10 and on it applied color decor 12 are in the illustrated embodiment no paint applied.

In the simplest variant shown in Figures 1 to 3 of the method according to the invention, the color decor 12 is removed from the carrier 14 transferred directly to the object to be decorated 16. The transfer takes place with "release" technology, i. H. the color decor 12 is placed on the object 16 with the aid of the carrier 14 and the carrier 12 is peeled off (like peeling one Decal). This is indicated by the arrow 18 in Figure 3.

Figures 4 to 7 show another embodiment of the Procedure in different steps. In Figures 1 to 7 are mutually corresponding or functionally similar layers and components with the same reference numerals.

According to FIG. 4, a color decor 12 is placed on a first carrier 10 applied, using printing techniques known as such.

Then the color decoration layer 12 is transferred from the first carrier 10 to one second carrier 14 transmitted. As in the first embodiment (Figures 1 to 3), the first carrier 10 consists of a well printable material, while the second carrier 14 from one Material that is used to transfer the decor to a Item 16 has good mechanical properties, in particular is particularly flexible and elastic. The above for the first Embodiment (Figures 1-3) materials called are also preferred here.

After the color decor 12 from the first carrier 10 to the second Carrier 14 has been transferred, a color decor 12 Paint layer 20 applied. This is shown in Figure 5. The Paint layer 20 is preferably chosen so that the paint later suitable as a base coat for the object 16 to be decorated is. The article 16 can be made from one of the materials mentioned at the beginning exist (e.g. glass, metal, ceramic, plastic, Wood, wood-based material, textile or leather).

Then the color decor 12 and the one lying on it Lacquer layer 20 from the carrier 14 to the object to be decorated 16 transferred. The transfer takes place with the "Release" property of the support 14, which in Fig. 6 with the arrow 18 'is indicated. The lacquer layer 20 lies on the bottom Item 16 and primes it. The color decor 12 lies on top.

FIG. 7 shows a further process step, namely the application a further lacquer layer 22 on the color decor layer 12th

A relatively large thickness is selected for the upper lacquer layer 22, in particular in the range from 40 to 120 μm, particularly preferred in the range from 60 to 100 µm.

After the second lacquer layer 22 has been applied, curing takes place, especially with electron beam (ESH). Both can Paint layers are hardened. Previously, the lower one Have been subjected to partial curing, in particular with UV radiation.

According to the ESH, a so-called "hot air knife" is used. This is shown in Figure 7. A hot air jet 26 flows through a nozzle 24 directly onto the top layer of paint 22. The hot air jet is in the illustrated embodiment, knife-shaped, d. H. he has the shape of a line perpendicular to the plane of the drawing stands and is preferred over the entire width of the paint and Dye layers and the article 16 extends. Such one "Hot air knife" can be relative to the arrow 28 Item 16 with the layers of paint and dye on it be moved.

Various effects can be achieved with the hot air knife 24, 26 become. First of all, the hot air knife can serve the Place the carrier 14 with the color decor layer 12 and the lacquer layer 20 to promote the item 16. Furthermore, the hot air knife also serve the peeling process in which the carrier 14 is subtracted from the color decor 12 to promote. Especially the effect of the hot air knife after curing is advantageous the lacquer layer 22 (whereby the hardening is only preferred with electron beam other hardening techniques are possible, which are known as such to the person skilled in the art). With the hot air knife the temperature of the upper lacquer layer 22 and the one below it Color layer 12 increased briefly so that there is a temperature gradient from top to bottom, d. H. the upper lacquer layer 22 is hotter than the lower lacquer layer 20. This causes the dye molecules from the color decor layer 12 diffuse into the upper lacquer layer 22. With diffusible Disperse dyes depend on the color of the dye usually depending on the molecular weight. So have yellow dyes typically a molecular weight of 200 to 300, red colors from 250 to 350, blue colors from 300 to 500 and black colors from 350 to 500. This has the consequence that in the above described thermal diffusion the bright dyes such. B. yellow, diffuse further distances into the upper lacquer layer 22 than the darker dyes, such as B. blue or black. This creates an interesting optical effect in terms of the depth effect of the color decoration achieved. The above Starches for the upper lacquer layer 22 enable this depth effect due to the different diffusion distances of the different dye molecules.

With the hot air knife 24, 26, the temperature can be local for a short time can be increased in order to bring about the said thermal diffusion. This leaves a temperature gradient for the diffusion process maintained without the temperature in all Compensates for layers. The temperature of the hot air 26 and the speed the relative movement (arrow 28) are set so that the effect explained above in terms of thermal diffusion occurs. In individual cases, the optimal Process parameters experimentally depending on the given Dye molecules, types of lacquer, layer thicknesses, etc. determined become.

The hot air jet also effects especially in the critical edge area the item 16 a good quality color decoration.

Claims (4)

1. A method of applying colour decoration to an article, comprising the following steps:

   a) applying a colour decoration (12) to a first support (10) having a release characteristic;

   b) transferring the colour decoration (12) from the first support (10) having a release characteristic to a second support (14) having a release characteristic, and

   c) transferring the colour decoration (12) from the second support to the article (16),

   characterised in that
   after step (b) a coating film (20) is applied to the colour decoration (12) which in step (c) is applied bottom-most to the article (16).
2. The method according to claim 1, characterised in that
   the applied coating film (20) is partially cross-linked prior to transfer to the article (16).
3. The method according to claim 1 or claim 2, characterised in that
   after step (c) an upper coating film (22) is applied to the colour decoration (12).
4. The method according to claim 3, characterised in that
   a hot gas jet (26) is directed onto the upper coating film (22).

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