EP0768957B1 - Blocking foil, in particular hot-blocking foil with decorative or warranty elements - Google Patents

Abstract

PCT No. PCT/DE95/00784 Sec. 371 Date Dec. 20, 1996 Sec. 102(e) Date Dec. 20, 1996 PCT Filed Jun. 10, 1995 PCT Pub. No. WO96/01187 PCT Pub. Date Jan. 18, 1996There is disclosed a hot stamping foil assembly, in particular a hot stamping foil, which has spatial decorative or security elements formed in a region-wise manner. An adhesive layer is provided only in a region-wise manner and in matching relationship with respect to the spatial elements to effect transfer of the spatial decorative or security elements or other decorative layer structure.

Description

The invention relates to an embossing film, in particular Hot stamping foil, consisting of a carrier film and a from this removable transfer situation, which - starting from the carrier film - at least a transparent one Protective lacquer layer, one of at least one layer educated, decorative or securing elements comprehensive decorative layer structure and one for fixing serving the transfer layer on a substrate Has adhesive layer.

Such stamping foils, in particular hot stamping foils, are known in a wide variety of embodiments. At their application will affect the transfer situation of heat and pressure from the carrier film to a substrate transferred on which the corresponding transfer situation by means of the adhesive layer, which is generally a hot glue or radiation curable Kleber acts, is liable. In a variety of Use cases, it is now the case that the transfer situation should not be transferred over the entire surface to the substrate but only certain areas of the transfer situation, for example, decorative elements in the Transfer situation in a manner known per se Printing processes etc. are generated. Especially for them Application of securing elements, for example on Securities such as banknotes, credit cards, ID cards etc. or other objects to be secured are also in large amount of hot stamping foils used. It is it is important that only the respective securing element or the the area corresponding to the securing element Transfer layer detached from the carrier film and on the substrate is set.

So far, one goes in general, if only one area Transfer of the transfer layer to the substrate is desired is, so that the stamping foil by means of accordingly shaped stamp is pressed against the base. Only in The stamp area is then transferred to the transfer location exerted the necessary pressure, which is intended to achieve that only that part of the stamped surface Transfer layer adheres to the substrate while the rest the transfer layer is peeled off with the carrier film.

This procedure has several disadvantages. For one thing It has been shown that the production of large quantities, for example when printing banknotes, required high working speeds and as a result, large transmission capacities can only be easily achieved when to apply of the stamping foil impression on the substrate rolling process be applied. Here it is difficult Train roles so that their surface through correspondingly raised areas forms individual stamps. This way of working continues to result Problems with the exact orientation of the transferring decorative or securing element with the stamp area used for the transfer.

If only areas of the transfer layer from the carrier film are transferred to the substrate by means of a stamp the problem still arises that only completely certain materials used for the transfer layer can be. The materials have to be chosen that way be that the transfer position along the stamp edge tears off cleanly, with a special selection the release layer between the transfer layer and carrier film it must be ensured that the transfer situation in the areas that are transferred to the substrate should be easily detached from the carrier film, but in the others Areas adheres perfectly to the carrier film. Especially then, if the temperature and So far, pressure conditions are not exactly right often before that you can't get a clean demolition of the Received transfer position along the edge of the stamp. Another disadvantage is that along the edge of the stamp easily tearing transfer layers in general are not mechanically resistant, which e.g. at a Security element, but also for a decorative element, means that when using the appropriate Object often after a very short time as a result mechanical influences is destroyed.

Attempts have already been made to to achieve improvements here by using stamping foils were used without an adhesive layer, the adhesive then attached in the areas of the substrate to be decorated and by means of the adhesive the transfer position from the Stamping foil has been removed. With such an approach you can use smooth rollers to apply pressure and heat work. However, they exist in the same way as with the use of stamps the problems regarding the composition of the transfer situation, the With this procedure, too, it must be constructed in such a way that correspondingly easily tears, which in turn is minor mechanical strength. Even the problems of poor fit between the adhesive and the decorative or Securing elements of the transfer situation are on not eliminated this way.

The invention is therefore based on the object Stamping foil, especially hot stamping foil, such to train that without special measures precise registration of individual areas of the Transfer layer in the form of decorative or Securing elements on a substrate is possible, but not particularly for transfer to the substrate shaped stamps are required but for example Rolls or rollers can be used. Furthermore it should also in a procedure according to the invention be possible, the transfer situation much more stable and to train mechanically more resistant.

To solve this problem, according to the invention proposed an embossing foil, in particular Hot stamping foil of the type mentioned above train that at least the adhesive layer only in some areas and with register that only locally trained decoration or Securing elements of the transmission position is provided, and the protective lacquer layer over the entire surface of the carrier film covers.

EP 0 461 475 describes an embossing film for transferring a Decor on a substrate known, one on a separate Carrier film provided adhesive layer is provided. Since the Transfer layer and the adhesive layer on two different Carrier films are arranged is the exact transfer of individual Elements from the transfer situation are only possible to a limited extent, since that Transfer must be done in two steps, first the transfer the adhesive layer and secondly the transfer of the Transfer situation.

A transfer film is also known from EP 0 413 819, at which in particular has a shiny metallic pattern on a substrate is transmitted, the shape of this pattern being determined by the shape of the Adhesive layer is determined because of the transfer layer and therefore also only transfer the metal layer to the substrate at the points on which an adhesive layer is provided. It is an embodiment of one Transfer film reveals the adhesive layer and above Metal layer correspond to each other. This is done in an elaborate process Procedure allows first on a corresponding Underlay a metal layer is applied over the entire surface subsequently in a predetermined pattern with an adhesive layer is provided. In a further step, the will not be through the adhesive layer covered metal layer with an acid or alkaline caustic solution removed.

It is essential in the stamping foils according to the invention thus that as a result of an only area-wise installation of the Adhesive layer ensures that the transfer layer only where there is an adhesive layer on the substrate is liable. So it does not matter whether or not outside of the adhesive layer pressure on the transfer layer is exercised. Nevertheless, only the area of Transfer layer that matches the adhesive layer, adhere to the substrate. This means that the boarding the transfer position on the substrate largely independent from the shape of the for pressing or heating if necessary tool is used. When using an embossing foil According to the invention it is therefore possible, for example, an area-like decoration or labeling or the like. a substrate in a continuous process, e.g. by means of rollers or rollers. Another The embossing foil according to the invention is also preferred in it see that a perfect match of Adhesive layer in some areas with the transferring areas of the transfer situation without Difficulties can be achieved because of the usual both the various layers of the transfer situation as well the adhesive layer is applied in a printing process become. It is well known that when printing, the perfect one Alignment of different, superimposed layers no difficulties. Another advantage in the process according to the invention is that embossing foils according to the Invention also for substrates with a very rough surface, for example paper, with excellent adhesion and physico-chemical resistance can.

The use of an embossing film according to the invention offers thus both considerable compared to the usual Advantages in terms of being transferred to the substrate usable tools, and especially with regard to Accuracy in the delineation of the substrate areas of the transfer layer to be applied. Farther allows the stamping foil according to the invention with the only Adhesive layer provided in certain areas in a variety of cases the use of mechanically essential more stable layers for the transfer layer. Even if in such a case during the transmission of the Limiting the area of the Transfer situation is not clean, can very easily in a further operation possibly over the adhesive layer protruding transfer layer material are removed, because in the area of the adhesive layer, the transfer layer very much adheres firmly to the substrate.

To remove the transfer layer from the carrier film too facilitate, in a manner known per se between the Carrier film and the transfer layer a release layer be provided, it being particularly advantageous if according to the invention, the release layer only in some areas and is provided in register with the adhesive layer. Such Formation of the stamping foil causes the Transfer situation in the areas where there is no peel layer is present, these areas with the areas match where no adhesive layer is provided, adheres comparatively firmly to the carrier film, as a result of which Tear off or the separation of the transfer layer along the edge of the area to be transferred is supported.

In the event that the release layer is only partially and passerhalting to the adhesive layer is provided, can according to the invention, the protective lacquer layer over the entire surface provided and formed by a paint on the Carrier film outside of that covered by the release layer Areas well adheres to a measure that is also a clean separation along the edge of the data to be transferred Supported areas of the transfer situation.

Especially as security elements are more recently often spatial structures with diffractive optics used because this is only comparatively difficult fake and also when trying to copy can produce special effects. In this context it is proposed according to the invention that the decorative or Securing elements from in the protective lacquer layer whose side facing away from the carrier film, diffraction-effective spatial structures formed are in register with the adhesive layer. The additional arrangement of such security elements in a transparent protective lacquer layer is known. It is essential, however, that the passport Arrangement of the spatial structures to the adhesive layer one perfect alignment and clean limitation of spatial structures is achieved and this in particular not fringed in the area of its edge, so far under Circumstances the entire appearance of a Securing element and further processing, e.g. Printing of the value document could be affected.

For improved visibility of the spatial structures can, in a manner known per se, the spatial Structured side of the protective lacquer layer Have coating whose optical properties differ differ from those of the protective lacquer layer, the Coating in particular from a reflective Material, preferably metal, is formed.

Although the spatial structures according to the invention in are generally in register with the adhesive layer, it is particularly beneficial if the coating takes place over the whole area, and that because Coatings over the entire surface much lighter and in front all without additional measures or work steps have it attached. Nevertheless, the full surface is annoying Coating usually not because of the layer thickness such coatings are so small that they Transfer to the substrate easily along the Edge of the areas bearing the adhesive layer. Of course, with particularly high quality films the coating also partially and in register spatial structure can be attached to make a special to achieve clean delimitation of the transferred layers.

Finally, it is within the scope of the invention that the Peel off the areas the adhesive layer and / or the decorative or Safety elements protrude on all sides by at least 0.2 mm. Surviving the protective lacquer layer and possibly the Removal layer over the decorative or securing elements and at the same time over the adhesive layer offers the advantage that the protective lacquer layer along during the transfer process its edge is applied closely to the substrate, being in general also the protruding area of the Protective lacquer layer adheres perfectly to the substrate because the Adhesive layer due to its thickness, even if only small still compressed during the transfer process and with it outwards towards the edge of the Protective lacquer layer is pressed.

Further features, details and advantages of the invention arise from the following description of two Embodiments of hot stamping foils according to the Invention based on the drawing.

Figures 1 and 2 show sections, each in section from the corresponding hot stamping foils. In this context it should be noted that the Thickness of the different layers not to scale is shown.

The hot stamping foils according to the exemplary embodiments each comprise a carrier film 1, for example one Polyester film with a thickness of approx. 20 µm. On an area this carrier film 1 is partially or over the entire area a release layer 2 in a layer thickness of approximately 0.01 applied up to 0.1 µm. Subsequent to the release layer 2 then follows, also over the entire surface (FIGS. 1 and 2) a transparent protective lacquer layer 3. The protective lacquer layer 3 has full surface Application of a layer thickness of 0.8 to 2.5 µm, preferably from 1.2 to 1.7 µm.

The transparent protective lacquer layer is in the shown Embodiments for the formation of securing elements, but possibly only for the formation of Decorative elements in the for transfer to the Substrate specific areas with an optical diffraction effective, spatial structure 4 provided, the spatial structures 4 by appropriate replication or embossing by means of a corresponding master at the the backing film 1 facing surface 5 of the Protective lacquer layer are formed.

Around the spatial structures 4 particularly clearly visible after the application of the Protective lacquer layer 3 and the corresponding introduction of the spatial structures 4 the entire free surface of the partially finished stamping foil with a coating 6 provided, preferably a suitable, reflective metal is evaporated in a vacuum. The The thickness of the coating 6 depends on which material is used for this. If it’s metal, it is on the order of a few nm, namely 5 - 50 nm (50 - 500 Å), preferably 10-20 nm (100-200 Å). The coating 6 can but also formed, for example, by a dielectric be compared to the material of the protective lacquer layer 3 different optical properties. Dependent The layer thickness can then depend on the type of material Coating 6 may be considerably larger.

The top layer (in the drawing) of the hot stamping foils each of the exemplary embodiments only forms one areas of adhesive 7, the Adhesive layer 7 essentially only in the areas is provided in which decorative or Securing elements, i.e. in the shown The spatial structures 4, available.

The adhesive layer 7 is usually in one Layer thickness from 3.0 to 10.0 microns, preferably from 4.0 to 6.0 µm.

The individual embodiments, of which in practice the embodiment of Figure 2 have the greatest importance should differ mainly by the different areas of attachment Protective lacquer layer 3 and release layer 2.

In the embodiment of FIG. 1, the release layer is 2 only appropriate in certain areas, namely in the areas in which the spatial structure 4 to form the decorative or Securing elements on the protective lacquer layer 3 and the Adhesive layer 7 are provided. Figure 1 shows that the release layer 2 the spatial structure 4 or the Adhesive layer 7 by a dimension a, which is at least 0.2 mm should be exceeded on all sides.

Finally, FIG. 2 shows both the release layer 2 and the protective lacquer layer 3 is provided over the entire surface. Only the adhesive layer 7 is only in the transmitting areas with the spatial structure 4 present, again the adhesive layer 7 by the measure a of at least 0.2 mm compared to the spatial structure 4 jumps back.

The production of hot stamping foils according to the Embodiments take place in itself from the Production of hot stamping foils in a known manner, that on the carrier film 1, the release layer 2 and the Protective lacquer layer 3 in a printing process in appropriate layer thickness or distribution applied become. The protective lacquer layer 3 is either thermoplastic or consists of a varnish that is only under Influence of certain radiation or after a certain time fully cures after crosslinking. In a thermoplastic protective lacquer layer 3 is the spatial Structure 4 under the influence of heat by means known per se Matrices stamped. If the protective lacquer layer 3 a under the influence of certain radiation, e.g. of UV radiation, or hardening after a certain time Paint layer, you bring the spatial structure 4 in a replication process in the surface 5 of the Protective lacquer layer 3, as long as the layer 3 forming Lacquer is not yet fully cured.

The partially finished film is then with the Provide coating 6, for example aluminum in appropriate thickness evaporated in vacuo. The Coating 6 can be both over the entire surface and partial and in register with the spatial structure 4 be formed. This is followed by again in a printing process, in some areas the Adhesive layer 7 applied, the registration of the Adhesive layer 7 opposite the release layer 2 (Figure 1) or the spatial structure 4 (Figure 2) by appropriate scanning of the already the carrier film 1 existing layers takes place. To this end can the release layer 2 if it is only available in certain areas, with a suitable one Marking pigment are added.

The individual layers can be composed as follows: Peeling layer, full area (Figure 2) Ethanol 98 g toluene 900 g Ester wax (dropping point 90 ° C) 2 g Peeling layer, in areas (Figure 1) Deionized water 740 g Polyvinyl alcohol (degree of hydrolysis: 98.4 ± 0.4 mol%) 8 g Ethanol 250 g Marking pigment (e.g. benzoxazole derivative) - to enable registration - 2 g Protective lacquer layer, all over (Figure 2) MEK 400 g toluene 150 g Cyclohexanone 200 g Cellulose nitrate (low viscosity, 65% in alk.) 148 g Butyl / methyl methacrylate (d = 1.05 g / cm ³ , acid number 7-9 mg KoH / g) 102 g

Adhesive layer, in some areas Recipe 1 MEK 100 g Xylene 200 g Cyclohexanone 255 g Polyvinyl chloride terpolymer (Tg = 90 ° C) 290 g SiO ₂ 50 g Polyisocyanate (50% ethyl acetate, NCO content 8%) 105 g Recipe 2 MEK 250 g toluene 340 g Vinyl chloride / vinyl acetate copolymer (mp: 80 ° C) 215 g Thermoplastic polyurethane (d = 1.18 g / cm ³ ) 135 g Silicic acid, hydrophobic (particle size approx. 10 µm) 60 g

The embossing foils are processed according to the Invention with the adhesive layer applied in certain areas pressed against a substrate in advance, the pressure for example by means of a full-surface steel wheel, but can also be done with a suitable segment wheel. Under correspondingly high pressure and at a suitable temperature then, supported by the release layer 2, the a total of 8 designated transmission situation, at least from a protective lacquer layer 3, the coating 6 and the Adhesive layer 7 consists of the carrier film 1, namely in essential only in those areas where a Adhesive layer 7 is provided. Should be too big as a result Stability of the protective lacquer layer 3 in the area of The edges of the adhesive layer 7 are not severed with sharp contours can be or tear off, by appropriate mechanical Action on the element transferred to the substrate the superfluous protective lacquer layer without major problems be removed because these are - because there is no adhesive layer 7 in the unwanted areas is there - not on Substrate adheres. However, this is usually the case additional work step not required.

If the embossing foils according to the invention are not as Hot stamping foils trained but for cold processing are determined, i.e. the adhesive layer also Room temperature is already sticky, there is Possibility of the carrier film 1 on the transfer layer 8 facing away with a corresponding coating to be provided that the adhesive layer 7 adheres to Carrier film 1 prevented when winding the films.

Claims (9)

1. Stamping foil, in particular hot-stamping foil, composed of a supporting film (1) and, capable of being released therefrom, a transfer layer (8) which - starting from the supporting film (1) - has at least one transparent protective layer (3), a decorative layer structure formed from at least one layer and encompassing decorative or security elements (4), and also an adhesive layer (7) for laying down the transfer layer on a substrate, where at least the adhesive layer (7) has been provided only in some areas and in registration with the decorative or security elements (4) of the transfer layer (8), which have been developed only in some areas, and the protective layer (3) covers the full surface of the supporting film (1).
2. Stamping foil according to Claim 1,
   characterized in that
   a release layer (2) has been provided between supporting film (1) and transfer layer (8).
3. Stamping foil according to Claim 1 and 2,
   characterized in that
   the release layer (2) has been provided only in some areas and in registration with the adhesive layer (7).
4. Stamping foil according to Claim 3,
   characterized in that
   the release layer (2) extends beyond the areas of the adhesive layer (7) and/or beyond the decorative or security elements (4) on all sides by at least 0.2 mm.
5. Stamping foil according to Claim 3 or 4,
   characterized in that
   the protective layer has been formed from a coating material which has good adhesion to the supporting film (1) outside the areas covered by the release layer (2).
6. Stamping foil according to one of the preceding claims,
   characterized in that
   the decorative or security elements have been formed from optically diffracting three-dimensional structures (4) which have been arranged in registration with the adhesive layer (7) and which have been developed in the protective layer (3) on its side (5) facing away from the supporting film (1).
7. Stamping foil according to Claim 6,
   characterized in that
   the protective layer (3) has, on its side (5) which has the three-dimensional structures (4), a coating (6) whose optical properties are different from those of the protective layer (3).
8. Stamping foil according to Claim 7, characterized in that the coating (6) has been formed from a reflecting material, preferably metal.
9. Stamping foil according to either of Claims 7 or 8, characterized in that the coating (6) has been provided over the full surface.

Images