WO2019206661A1 - Method for producing a laser-modified transfer image or heat transfer - Google Patents

Abstract

The invention relates to a method for producing a transfer image, comprising the following steps: a) providing a multi-layer arrangement comprising at least one carrier film and a coating layer and/or colour layer with laser-reactive pigments; b) providing the coating layer and/or colour layer with lettering and/or a drawing by means of a laser beam of a laser and applying to a support before or after said laser irradiation; and c) removing the carrier film; the laser beam being guided through the carrier film to the coating and/or colour layer and/or from a side facing away from the carrier film (2) to the coating and/or colour layer (3, 4). The invention also relates to a transfer image.

Description

 Method for producing a laser-modified decal or

 heat transfers

The present invention relates to a method for producing laser-modified decal or heat transfer.

Various methods for applying a drawing or lettering to a substrate are known from the prior art.

DE 10 20014 1 15 910 describes the labeling of a label. in the

Unlike a decal, no layers are removed from the labeled surface at the end of the process. It is therefore another application with other process engineering

Requirements.

From DE 94 29 174 U1 a method for printing printed conductors on a laminate of a rigid printed circuit board is known. Here, laser light is passed through a translucent film and blackens an underlying

Underground.

WO 2017/108623 A1 discloses an adhesive film in which laser-reactive pigments can be arranged. However, an indication of a production process using these special laser-reactive pigments is not known from this document.

Based on the aforementioned prior art, it is the object of the present invention to provide a method for producing a decal, with which decals with high quality and with little time can be produced, which, however, as in digital printing

preferably individually for each decal or heat transfer individually

can be individualized.

The present invention solves this problem by a method with the

Features of claim 1.

A method according to the invention for producing a decal or heat transfer comprises the following steps: a) providing a multi-layered decal or

 Heat transfer as an arrangement comprising at least one carrier film and a paint and / or ink layer with laser-reactive pigments;

The multilayer arrangement may comprise further layers.

Thus, it is advantageously possible that not only a color and / or lacquer layer but also a plurality of lacquer and / or color layers can be provided.

It is also advantageously possible for these multiple layers to comprise pigments, in particular laser-active pigments. Since the layers can reduce the intensity of the incoming laser light, a

Layer by layer staining be made, with the

Discolour pigments in the subsurface layers to a lesser extent, so that the staining is less intense, even if the same pigments are used.

It is also advantageously possible to use pigments with different chemical composition and thus different color change in

to use different color and / or lacquer layers. As a result, a multi-color can be achieved. b) providing the paint and / or ink layer with a lettering and / or a drawing by a laser beam of a laser and application to a substrate before or after the aforementioned laser irradiation;

In this process step, a lettering or a drawing, ie a pattern of lines and lines, are applied by the laser. Also symbols e.g. Pictograms can be reproduced as a drawing. The lettering includes letters u.a. also numbers.

Before or after providing a label or drawing, the application can be carried out on a substrate. Here, advantageously, an adhesive layer offers, which allows a fixation on the ground. c) removing the carrier film; For a decal typical now the carrier film is removed, so that the made by laser decal remains with the or the corresponding color and / or lacquer layer on the substrate to be applied.

A special feature of the present method is that the laser beam is passed through the carrier film on the paint and / or ink layer.

 As an alternative to the conduction of the laser beam through the carrier, it is possible to direct the laser beam to the pressure side of the transfer and therefore from the

Back, so from the backing film opposite side

individualize. This can be done by direct irradiation of the paint and / or

Color layer or preferably by irradiation through an adhesive layer through.

As a result, for example, an on-site prefabrication of the decal take place, which at the application, typical of a decal or

Heat transfer, only from the carrier film and possibly an optional backing paper must be separated. Alternatively, customers will be able to carry out customization by laser directly on site. As a result, secrecy, automation with software systems and / or a

Individualization at the earliest possible date for a more flexible production of the customer, be complied with.

The laser-modified decal and / or the laser-modified heat transfer is flexible in contrast to a printed circuit board and pursues a decorative goal, whereas tracks are a purely technical implementation. The lettering of the decal or heat transfer is characterized by the fact that it can also be done before applying the target substrate (application background).

Advantages of this procedure are u.a. an ink-free printing process, a high resolution design of a label and / or a drawing and a possible uncomplicated transport, storage and application of the decal to a substrate.

The method can thus combine the advantages of a highly productive uniform printing process such as screen printing with the advantages of individualization such as digital printing by the possibility of individualization by means of laser. Advantageous embodiments of the method according to the invention are

Subject of the dependent claims.

By the laser beam, a color change of the pigments can take place, wherein the number of excited pigments and thus the intensity of the color change by the laser adjustment, in particular the intensity of the laser beam and the wavelength, are adjustable. This has the advantage that a light / dark graduation can be achieved analogously to a gray scale print.

The production of the decal by color change of the laser-reactive

Pigments can in particular be ink-free, so that staining on other print media is excluded. At the same time the printed image is protected.

For easy and residue-free detachment of the release layer from the adjacent paint or ink layer, the multi-layer decal or heat transfer as a multi-layered arrangement between the carrier film and the paint and / or ink layer, a release layer, preferably on silicone and / or wax base have ,

For optimal irradiation of the carrier film by the laser while at the same time having sufficient tear resistance, the carrier film during stripping is a thickness of between 75 and 130 μm particularly advantageous.

The laser used can advantageously be operated in the present process up to a power of up to 20 W, so that the matrix material of the paint and / or lacquer layer is not excessively damaged or even thermally decomposed upon irradiation of the pigments.

For advantageous fixing on a substrate, the paint and / or ink layer can advantageously have an adhesive layer on an opposite side of the carrier film. The carrier film forms starting from the viewing direction of an observer (arrow A) of the decal the top and the adhesive layer can form the bottom.

Alternatively, however, the bottom can also be formed by a masking paper, which premature unintentional bonding of the adhesive layer prevented. This can also be formed with a release layer, in particular of silicone or wax material.

The lacquer and / or color layer and / or the adhesive layer may have at least 50% by weight of a polyurethane and / or acrylate, which has proven to be comparatively insensitive to laser radiation. A lacquer layer in the sense of the present invention, in contrast to a color layer, has a functional character. In particular, protective effects, ie the use as a protective layer to protect an underlying color layer, can be realized thereby. In contrast to decoratively effective layers of paint, a lacquer layer is also transparent or semitransparent and controls the degree of gloss.

A color layer is in particular through the use of other additives the

Application for example by screen printing and pigments delimited from a paint layer.

The color layer may additionally comprise at least one further non-laser-reactive pigment, in particular TiO ₂ , carbon black or the like, around a stronger one

Contrast to achieve the color change.

Furthermore, according to the invention is a decal, which was prepared by the aforementioned method.

The invention will be explained in more detail with reference to an embodiment. The particular details are in no way limiting

understand. In particular, numerous details taken separately can be implemented as separate features in a similar manner in further embodiment variants.

Fig. 1 is a schematic representation of an embodiment of a

 provided decal for use in a

 inventive method for producing the laser-modified decal;

Fig. 2 is a schematic representation of a laser irradiation of the decal of

Fig. 1; Fig. 3 remaining color layers on a substrate after application of the decal; and

Fig. 4 schematic representation of an alternative laser irradiation in

 Comparison to FIG. 2.

1 shows a decal in the form of a multilayer arrangement 1 comprising a carrier foil 2, a sequence of a plurality of color and / or lacquer layers 3 and 4, an adhesive layer 5 and a cover paper 6.

The carrier film 2, also called carrier, can be at least 50% by weight, based on the total weight of the carrier film 2, preferably formed entirely from a polyethylene terephthalate. Of course, the carrier film may also consist of other materials.

The carrier film 2 can also be coated with a release layer 8. This separating layer 8 can preferably be based on at least one silicone and / or a wax material or for the most part, in particular more than 50% by weight, based on the total weight of the separating layer.

In addition, however, the release layer may also comprise other materials. The release layer 8 is arranged on the color layer 4 facing side of the release film 2.

Preferably, the carrier film 2 is transparent or at least translucent. The carrier film 2 also has a thickness of 75 to 130 pm.

The arrangement 1 may have an optional lacquer layer 3 adjacent to the carrier foil 2 or to the tear layer 8. This may be formed as a layer comprising at least 50% by weight, based on the total weight of the lacquer layer 3, of binders on a polyurethane and / or acrylate-based layer.

Furthermore, lacquer layer 3 may advantageously be additionally enriched with additives, such as leveling agents.

Adjacent to the lacquer layer 3, one or more color layers 4 can then be arranged. A preferred ink layer may comprise at least about 50% by weight, based on the total weight of the respective ink layer, of a binder. The binder can be formed on polyurethane and / or acrylate-based be. Furthermore, the color layer 4 can comprise pigments, but preferably not exclusively white pigments, particularly preferably with TiO 2, and / or additives, particularly preferably film formers.

The one or more paint and / or ink layers 3 and / or 4 are in particular mixed with a laser-reactive pigment 7 or a laser-reactive pigment-containing granules or powder, which can be excited by laser radiation to a permanent color change. The pigment may in particular be selected from substances comprising: SnSb oxide, Sb ₂ 0 _3, CU ₃ (PO ₄ ) ₂ CU (0H) ₂ , mica (phyllosilicate and / or mica), Fe ₃ 0 ₄ or

Mixtures. Likewise, these are characterized by a size between 1 and 70 pm. The laser-reactive portions may preferably be contained in a powder or granules and thereby be encapsulated or unencapsulated.

Adjacent to the lacquer and / or color layer, an adhesive layer 5 for fixing one or more of the aforementioned layers on a substrate 10 is provided. The adhesive layer 5 may have at least 50% by weight, based on the total weight of the respective ink layer, of a polyurethane and / or acrylate, and optionally additives. The adhesive layer may be permanently adhesive in the case of decals, or as particularly in the case of

Heat transfers can be activated by heat. This can be for example a so-called hot melt adhesive.

The adhesion of the adhesive layer is usually so high that a non-destructive redetachment of the decal or heat transfer is not possible.

A masking paper 6 may be disposed adjacent to the adhesive layer 5.

This paper can also optionally but not exclusively, with a

Separating layer 9 to be coated.

This release layer 9 may preferably be based on at least one silicone and / or wax material or for the most part, in particular the aforementioned silicone and / or wax material to more than 50 wt.%, Based on the total weight of the release layer have. In addition, the

However, separating layer also include other materials. The release layer 9 is arranged on the adhesive layer 5 facing side of the cover 6. The release layer 9 and the cover 6 prevent unwanted

premature bonding of the adhesive layer 5.

Each of the aforementioned layers, in particular all of the aforementioned layers, may be water- or solvent-based, i. the application is carried out in a solution of water and / or a solvent.

In the following, methods for producing the decal will be briefly explained:

In a first step, see FIG. 1, the multi-layered arrangement 1 is provided with the carrier foil 2, the cover paper 6, the lacquer and / or color layer (s) 3 and / or 4 and the adhesive layer 5.

In a second step, see Fig. 2, the laser treatment of the

provided arrangement. In this case, a laser beam 101 of a laser source 100 is passed through the transparent or translucent carrier film and excited to a color change and thus a change of the decal is generated. Alternatively, the laser can also be directed from the back directly onto the transfer, which is shown in FIG. In Fig. 4, the introduction of the

Laser beam from one of the carrier film 2 opposite side of the paint and / or ink layer 3, 4th

The adhesive layer 5 can, as shown in Fig. 4, already applied to the paint and / or ink layer 3, 4 or only after the

Being deposited.

The cause of this color change is the excitation of the laser-reactive pigments 7 or of the powder or of the granules by the laser beam 101. In particular, the surrounding polymer can also be dyed indirectly.

The aforementioned laser-reactive pigments or pigment-containing granules absorb the laser light and enable color change. This can i.a. also include carbonation or foaming. As a rule, these phenomena occur simultaneously, with the color change of the polymer

is predominant to avoid damage by combustion. This is also to be seen in contrast to the labeling by pure combustion of a coloring or other organic layer.

It is also possible that the matrix surrounding the pigment, e.g. the binder of the color layer or the material of which the color layer is predominantly formed is dyed. This can e.g. by rearrangement of complexes, by phase changes or the like.

Then, in a third step, the release of the masking paper 6 from the adhesive layer 5 to provide an adhesive surface for fixing the

Decal and the job on a substrate 10.

The substrate may be, for example, a stone, glass, wood, metal or preferably plastic substrate

In a fourth step, the removal of the carrier film 2 from the paint and / or ink layers 3, 4 then takes place, wherein the decal remains on the substrate 10.

The aforementioned second and third steps may alternatively also in the

Order be reversed, so that first the application of the arrangement 1 comprising the carrier layer 2 on the substrate 10 is carried out and then the laser treatment to produce the decal occurs.

As a laser-modified decal 20 or laser-modified heat transfer is understood in the context of the present invention, the modified decal or heat transfer, which was individualized by laser irradiation to color patterns of the dye and / or varnish layer.

This decal 20 remains in the result without a carrier film on the substrate 10 to be decorated.

As a laser for labeling, a semiconductor laser, such as a YV0 ₄ laser or YAG laser can be preferably used. The preferred one

Wavelength range can be between 550 and 1070 nm.

Most preferably, it is a laser that has a 3-axis scanning system. In this case, the additional Z-axis, for example, also for Adjust the autofocus position and / or adjust the focal distance. The focal distance can be determined by a secondary laser beam, which in addition to the laser beam 101, which makes the energy input into the arrangement.

Particularly preferably, the paint or ink layer 3 and 4 may comprise several layers, so that when the color of the pigment a depth effect or different intense color changes are observed and thus a color gradation can be achieved or a general imaging by the pressure such as screen printing, given is.

By changing the intensity and / or the wavelength of the laser, in addition, the intensity of the energy input and thus the intensity of the color change can be varied. To ensure the correct parameters, so-called parameterization tests are to be carried out for each print batch.

By using different layers with each other

different pigments, the color variance can be additionally increased.

In Fig. 1, only one color layer 4 is shown. Advantageously, at least five, preferably at least seven, color layers 4 arranged one above the other can be provided.

Each of these color layers may comprise a laser-reactive pigment.

The decal or the heat transfer provided in step a) may in one embodiment of the invention be monochromatic, e.g. know, be educated.

However, the decal provided in step a) or the heat transfer may already have a printed layer e.g. as a color layer or decorative layer below the color and / or lacquer layer 3, 4, which with

conventional printing methods, e.g. Screen printing, were printed. In this case, the laser treatment can be pre-printed decor around a drawing or

Complete the label. As a result, an individualization eg of a logo can be achieved. reference numeral

1 arrangement

2 carrier film 3 lacquer layer

4 color coat

5 adhesive layer

6 masking paper

7 pigment

8 separating layer

9 separating layer

10 Substrate 20 Decal 100 Laser

101 laser beam

A viewing direction

Claims

claims 1. A method for producing a laser-modified decal (20) or  Heat transfers include the following steps  a) providing a multi-layered decal (1) or  Heat transfers comprising at least one carrier film (2) and a lacquer and / or ink layer (3, 4) with laser-reactive pigments (7);  b) Providing the lacquer and / or color layer (3, 4) with a label  and / or a drawing by a laser beam (101) of a laser (100) and application on a substrate (10) before or after  aforementioned laser irradiation; and  c) removing the carrier film (2);  the laser beam (101) being guided by the carrier film (2) onto the paint and / or ink layer (3, 4) and / or by one of the carrier film (2)  opposite side on the paint and / or ink layer (3, 4) is passed. 2. The method according to claim 1, characterized in that by the  A color change of the pigments (7) or indirectly of the  surrounding polymer occurs, wherein the number of excited pigments and thus the intensity of the color change by the laser adjustment, in particular the intensity of the laser beam (101) and its wavelength, is varied or adjusted. 3. The method according to claim 1 or 2, characterized in that the  Producing the laser-modified decal (20) by color change of the laser-reactive pigments, in particular ink-free, takes place. 4. The method according to any one of the preceding claims, characterized  in that the multi-layered decal (1) or the multi-layered heat transfer in step a) between the  Carrier film (2) and the paint and / or ink layer (3, 4) has a release layer (8), preferably on a silicone and / or wax base. 5. The method according to any one of the preceding claims, characterized in that the carrier film (2) has a thickness of between 75 and 130 μm. 6. The method according to any one of the preceding claims, characterized in that the laser (100) in step b) is operated with a power up to 20 W. 7. The method according to any one of the preceding claims, characterized  characterized in that the lacquer and / or color layer (3, 4) on one of the carrier film (2) opposite side has an adhesive layer (5). 8. The method according to any one of the preceding claims, characterized  in that the lacquer and / or color layer (3, 4) and / or the adhesive layer (5) has at least 50% by weight of a polyurethane and / or acrylate. 9. The method according to any one of the preceding claims, characterized in that the ink layer (3, 4) has at least one further non-laser-reactive pigment, in particular TiO ₂ . 10. The method according to any one of the preceding claims, characterized  characterized in that the multi-layered decal (1) or the multi-layered heat transfer in step a) also a cover paper (6), in particular a cover paper (6) with a release layer (9), for the protection of the adhesive layer (5). 11. The method according to any one of the preceding claims, characterized  characterized in that the multi-layered decal and / or the multi-layered heat transfer (1) are flexible. 12. Decal (20) produced by a method according to one of  previous claims.