EP2934898B1 - Sheet substrate for the production of security documents and securities - Google Patents

Description

The invention relates to a flat substrate sheet for the production of security and value documents, with two opposite major surfaces and with edges and corners connecting the edges, which form a peripheral edge of the substrate sheet.

The term substrate sheet in the present application refers to a sheet of a substrate material suitable for the production of security and value documents, such as a paper sheet or a foil composite sheet (hybrid sheet), which consists of a plurality of mutually alternating film and paper layers.

During the processing of such substrate sheets, in some cases, for example in the printing of composite foil sheets in steel printing, a so-called parachute formation can occur in the delivery. The printed sheet does not sail flat into the display, but the corners fall first downwards. This has disadvantages for the laying behavior of the sheets, as the corners with relatively high pressure on the fresh color of the underlying sheet to slide. This carries the risk that the colors smudge and deposit on the opposite arch. Reduced stacking heights and system speeds result in reduced productivity.

Out EP 1800891 A1 For example, a security document, for example a banknote, is known in which a line-shaped pattern of blind embossed or colored embossed structures is arranged near the edges in order to reinforce the edges of the security document.

Proceeding from this, the object of the invention is to avoid the disadvantages of the prior art and in particular to increase the productivity in the processing of substrate sheets, ideally combined with an improved flatness behavior of the sheets.

This object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

According to the invention, a planar substrate sheet of the type mentioned on at least one major surface at least in the region of the edge of the substrate sheet on a stabilizing layer for mechanical stabilization of the substrate sheet.

In an advantageous variant of the invention, the stabilization layer may be provided along the entire circumferential edge of the substrate sheet in order to stabilize the sheet uniformly. In another, likewise advantageous variant of the invention, the stabilization layer is provided in the region of the edge of the substrate sheet only at the corners of the substrate sheet, and then serves in particular for corner stabilization. In a further advantageous variant, the stabilization layer in the region of the edge of the substrate sheet is provided only at two corners and the side edge connecting the two corners, and then serves in particular for edge stabilization, with stabilization of the leading edge lying in the process direction contributing particularly to improved deposition behavior. In a further advantageous variant of the invention, the stabilization layer in the region of the edge of the substrate sheet in the form of a plurality of oblique strips, which are arranged spaced along the peripheral edge of the substrate sheet.

It is understood that the stabilization layer does not have to be present exclusively in the edge region of the substrate sheet, but rather that the stabilization layer next to it can also have partial regions lying in the interior of the substrate sheet. These inner subregions serve, in particular, for stabilizing individual components arranged on the substrate sheet after their separation.

The partial region of the stabilization layer provided in the edge region of the substrate sheet advantageously lies outside of individual components arranged on the substrate sheet, so that it can be readily removed in a later method step when cutting the substrate sheet. In contrast, the inner portions of the stabilizing layer usually remain after cutting the substrate sheet part of the isolated individual benefits and serve primarily their stabilization. With suitable design, these subregions can also be integrated as design elements in the single-use, as explained in more detail below.

The stabilization layer may be provided on only one of the two main surfaces or on both main surfaces of the substrate sheet. In the case of two-sided printing of a substrate sheet, the stabilization layer is preferably also applied to both main surfaces.

In an advantageous embodiment, it is provided that the stabilization layer has a constant thickness.

The stabilization layer is advantageously formed by a printing layer, in particular by a color or lacquer print. For example, gravure, flexo or steel printing are suitable as printing processes. preferred Printing process is currently, however, the screen printing method, as it can achieve high layer thicknesses at high viscosities or a high solids content.

The paints used for printing can be transparent or colored. In the case of hybrid sheets in particular, additional security features or security prints can be introduced when printing the stabilization layer onto the paper layer. A stabilizing layer with a relatively high layer thickness can still be tactilely detectable even after lamination, thus forming, for example, a tactile security feature.

In particular, when printing on a paper layer, such as a paper sheet or the paper layer of a hybrid sheet, it may be advantageous if the material of the stabilizing layer partially penetrates into the paper layer. This can be achieved, for example, in printing by the use of water-based paints or solvent-based systems. In contrast, solvent-free systems, such as 100% UV coatings, are particularly preferred when large layer thicknesses are desired. The paints used are advantageously characterized by high flexibility and tear strength. It is usually also advantageous if the paint behaves less fluid after printing.

Instead of a pressure layer, the stabilization layer can also be formed by a nozzle application layer. In this case, for example, low-viscosity adhesives can be used and applied by a nozzle application, which penetrate into a paper layer of the substrate sheet. In addition to stabilization, the penetration of the adhesives can cause a visible transparency of the paper layer.

In advantageous configurations, the stabilization layer is applied at least in partial regions, if appropriate also completely, directly on the substrate sheet, in particular a paper sheet. It may be advantageous if the stabilizing layer in the contact region with the substrate sheet, in particular a paper sheet, partially penetrated into this.

In other, likewise advantageous configurations, the stabilization layer is separated from the substrate sheet by one or more intermediate layers, at least in some areas, if appropriate also completely. At least one intermediate layer is advantageously formed by a film, a laminating adhesive and / or a paint receiving layer.

It is understood that the stabilizing layer according to the invention can be arranged on at least one main surface of the substrate sheet and at the same time can be arranged in a region which is separated from the substrate sheet by one or more intermediate layers. For example, in the case of a film composite sheet (hybrid sheet), the stabilization layer may be disposed on at least one major surface of the substrate sheet and further on at least one film or at least one ink accepting layer. The reason for the particularly good stabilization of this embodiment is currently considered to be that altogether relatively high amounts of stabilizing layer are applied to the substrate sheet in different areas or on different layers of the substrate sheet. In such embodiments, the stabilization of the substrate sheet is therefore extremely good, ie, effects such as the above-mentioned parachuting are substantially completely prevented.

The substrate sheet is in particular a paper sheet, the paper layer of a film composite sheet (hybrid sheet) or a composite film sheet (hybrid sheet), preferably with a layer structure film / paper / foil or paper / foil / paper. It should be noted here that multilayer composite sheets which have at least one paper layer are referred to hereinafter as "composite film sheet" or "hybrid sheet". In a corresponding manner, for example, in the case of a banknote which has at least one layer of paper and at least one further layer of foil, it is referred to as a "foil composite banknote" or a "hybrid banknote". The use of the terms "film composite" or "hybrid" is therefore to be construed in the context of the present application as a synonym.

As a polymer substrate, it is also conceivable to use a single-layered polymer substrate, e.g. from BOPP or PET, and to use other polymers or crosslinked polyolefins or crosslinked polyamides.

If the substrate does not have at least one paper layer, in the context of the present application a "polymer substrate", in particular a "polymer banknote" is used. Such a polymer substrate may be single-layered or multi-layered. For example, such a polymer substrate can be formed from two interconnected polymer webs of biaxially oriented polyolefin, in particular biaxially oriented polypropylene (BOPP). However, a polymer composite comprising a total of three layers is also conceivable, the middle polymer web being formed from BOPP, while the outer film webs applied on both sides of this middle web are formed from PET (layer sequence: PET / BOPP / PET). For such polymer substrates, penetration of the stabilizing layer into the polymer substrate is described below explained on the film layer of a film composite substrate, usually not possible.

• eine Vermeidung von Fallschirmbildung insbesondere im Stichdruck;
• eine Reduzierung des Ablegens, insbesondere von Offset- und Stahldruckfarben;
• eine bessere Planlage in der Auslage von Druckmaschinen; und
• ein besseres Gleitverhalten der Bogen.

The stabilization layer provided according to the invention achieves in particular the following advantages:

• an avoidance of parachuting, especially in stitches;
• a reduction of the depositing, in particular of offset and steel printing inks;
• a better flatness in the delivery of printing presses; and
• a better sliding of the bow.

Further exemplary embodiments and advantages of the invention are explained below with reference to the figures, in the representation of which a representation true to scale and proportion has been dispensed with in order to increase the clarity.

Fig. 1

schematisch einen Papierbogen nach einem Ausführungsbeispiel der Erfindung,

Fig. 2

einen Querschnitt des Bogens von Fig. 1 im Randbereich entlang der Linie II-II,

Fig. 3 bis 6

Querschnitte wie in Fig. 2 für andere Ausführungsbeispiele der Erfindung,

Fig. 7

in (a) bis (c) weitere, durch Stabilisierungsschichten stabilisierte Gestaltungen erfindungsgemäßer Papierbogen.

Show it:

Fig. 1

schematically a paper sheet according to an embodiment of the invention,

Fig. 2

a cross section of the arc of Fig. 1 in the edge area along the line II-II,

Fig. 3 to 6

Cross sections as in Fig. 2 for other embodiments of the invention,

Fig. 7

in (a) to (c) further stabilized by stabilizing layers designs of paper sheets according to the invention.

The invention will now be explained using the example of paper sheets for the production of banknotes. Figures 1 and 2 schematically show a paper sheet 10, which carries a plurality of individual benefits 12, which correspond to later cut banknotes. It shows Fig. 1 the paper sheet 10 in supervision, and Fig. 2 shows a cross section of the arc in the edge region along the line II-II of Fig. 1 ,

As in the Figures 1 and 2 recognizable, the paper sheet 10 has opposite first and second major surfaces 14,16, four corners 18 and four side edges 20 connecting the corners. The corners and side edges form a peripheral edge 22 of the paper sheet 10. Fig. 1 11 shows a plan view of the first main surface 14, which represents the front side of the paper sheet 10 and also the banknotes produced from the single-use 12. On this first main surface 14 of the paper sheet 10, a stabilizing layer 24 according to the invention is applied, which runs along the entire circumferential edge 22 of the substrate sheet.

The circulating stabilization layer 24 mechanically stabilizes the paper sheet 10 and thereby avoids the above-mentioned parachuting during processing. In addition, by the stabilization layer 24, the deposition of about offset and steel inks can be reduced. Also, a better flatness in the delivery of printing presses and a better sliding behavior of the sheet is achieved.

The stabilization layer 24 is located outside of the individual bumps 12 and is removed in a later step in the process of cutting the paper sheet 10 into the individual bumps 12.

In the embodiment of Figures 1 and 2 To produce the stabilizing layer 24 in the edge region 22 of the sheet by screen printing a paint 26 or a color was printed. The thickness of the imprint (amount of ink) and the physical properties of the optionally cured layer (flexible, brittle, degree of crosslinking, solvent-based, solvent-free, etc.) can be selected according to the desired layer properties. It is also important to note the time of application, in particular whether the order is made on base paper, on composite film or on finished hybrid with ink-accepting layer.

In the embodiment of Fig. 2 the lacquer 26 is applied directly to the base paper 30 without intermediate layers, so that the lacquer can penetrate into the paper in a surface region 32 and thus fix the paper fibers more strongly. Over the stabilizing layer 24, a film 34 with laminating adhesive and a paint receiving layer 36 are provided.

Instead of applying the stabilizing layer only on one major surface of the sheet, a stabilizing layer 24 can also be provided on both main surfaces 14, 16 of the paper sheet 10, as in the cross section of FIG Fig. 3 illustrated. In this embodiment, the stabilizing layer 24 of the two main surfaces was produced by printing a printing ink 40 by screen printing. By using the screen printing method, high layer thicknesses can be achieved at high viscosities or a high solids content. Similar to the design of the Fig. 2 the ink 40 penetrates into a surface area 32, such as the base paper 30 of the paper sheet, thereby fixing the paper fibers. On both main surfaces 14, 16, a film 34 with laminating adhesive and a paint receiving layer 36 are respectively applied over the stabilizing layer 24.

The variant of Fig. 4 corresponds largely to the Fig. 3 shown embodiment, wherein the stabilizing layer 24, however, in contrast to Fig. 3 is formed by a strong penetrating imprint 42.

This can be achieved for example by the use of a water-based paint or by the use of solvent-based systems. How out Fig. 4 As can be seen, the material of the imprint 42 and thus the stabilization layer 24 penetrates into the base paper 30 overall in a deep penetration region 44. The desired mechanical stabilization is achieved without a thick layer application is generated on the surface of the sheet. This can be useful in particular if the stabilization layer 24 also has subareas in the interior of the paper sheet and in particular in the area of the individual bumps 12 which are to remain in the finished banknotes.

At this point, it should be noted that the depth of penetration of the stabilization layer depends on many influencing factors, for example the quality of the substrate used, in particular paper, and the quality of the print used as stabilizing layer, in particular of the paint used. Furthermore, the penetration depth also depends on the amount of material applied to the substrate to be stabilized, in particular the amount of stabilizing lacquer applied. Another factor for the penetration depth is the time until hardening of the stabilizing layer after the application, since from a certain degree of cure further penetration of the stabilizing layer into the substrate to be stabilized is no longer possible. More generally, however, it can be said that the depth of penetration from each side of the substrate can be so great that the stabilizing layers deposited on the two opposing major surfaces of the substrate overlap within the substrate. That is, the Stabilization layer penetrates the entire substrate thickness in such a particularly preferred embodiment.

In the embodiment of the Fig. 5 , whose structure is basically the structure of the embodiment of Fig. 3 follows, the stabilizing layer 24 is not applied directly to the paper sheet 10, but is disposed between a sheet 34 applied to the sheet 34 and the ink receiving layer 36. In this variant, the stabilization layer 24 does not penetrate into the paper sheet 10.

Another possibility for arranging the stabilization layer 24 is in FIG Fig. 6 where the stabilizing layer 24 is separated from the paper sheet 10 by both a film 34 and a ink accepting layer 36. In this variant too, the stabilization layer 24 does not penetrate the paper sheet 10.

Fig. 7 shows three further, by stabilizing layers 24 mechanically stabilized designs of paper sheet 10. In the embodiment of the Fig. 7 (a) only the corner regions 50 of the paper sheet 10 are provided with the stabilization layer 24. The stabilization layer 24 present in the corner regions 50 also lies outside of the individual terminals 12 and is removed in a later method step.

With reference to the representation of Fig. 7 (b) For example, in an alternative embodiment, the stabilization layer 24 may also be provided only at the two upper corners 52 and at the side edge 54 extending between these corners. Thereby, the leading edge of the paper sheet 10 is stabilized for storage.

In another, in Fig. 7 (c) As shown, the stabilizing layer 24 is in the form of a plurality of oblique strips 56 which are spaced along the peripheral edge 22 of the paper sheet 10 around the individual ends 12 and thereby mechanically stabilize the sheet edge. By the width and the distance of the individual strips 56 from each other, the additional basis weight and thus the effect of the stabilizing layer can be varied and adjusted as desired, so that a different storage behavior of different paper sheets can be readily taken into account.

LIST OF REFERENCE NUMBERS

10

sheet of paper

12

individual benefits

14, 16

main areas

18

corners

20

margins

22

surrounding border

24

stabilizing layer

26

paint

30

base paper

32

surface area

34

foil

36

Trapping layer

40

printing ink

42

imprint

44

penetration region

50

corner areas

52

corners

54

margin

56

oblique stripes

Claims (12)

1. A flat substrate sheet for the production of security and value documents, the sheet having two opposing main surfaces and corners and side edges connecting the corners, which side edges form a peripheral edge of the substrate sheet, characterized in that the substrate sheet comprises a stabilization layer for mechanical stabilization of the substrate sheet on at least one main surface at least in the region of the edge of the substrate sheet.
2. The substrate sheet according to claim 1, characterized in that the stabilization layer is provided along the entire peripheral edge of the substrate sheet.
3. The substrate sheet according to claim 1, characterized in that the stabilization layer is provided in the region of the edge of the substrate sheet only at the corners of the substrate sheet or only at two corners and the side edge connecting the two corners.
4. The substrate sheet according to claim 1, characterized in that the stabilization layer in the region of the edge of the substrate sheet is in the form of a plurality of oblique strips which are arranged spaced along the peripheral edge of the substrate sheet.
5. The substrate sheet according to at least one of claims 1 to 4, characterized in that a stabilization layer is arranged on both main surfaces of the substrate sheet.
6. The substrate sheet according to at least one of claims 1 to 5, characterized in that the stabilization layer has a constant thickness.
7. The substrate sheet according to at least one of claims 1 to 6, characterized in that the stabilization layer is formed by a printing layer, in particular by a color or lacquer print.
8. The substrate sheet according to at least one of claims 1 to 7, characterized in that the stabilization layer is applied at least in subregions directly on the substrate sheet, in particular a paper sheet.
9. The substrate sheet according to claim 8, characterized in that the stabilization layer partially penetrates into the substrate sheet, in particular a paper sheet at the contact region with the substrate sheet.
10. The substrate sheet according to at least one of claims 1 to 9, characterized in that the stabilization layer is separated from the substrate sheet to one or more intermediate layers at least in some subregions, in particular that at least one intermediate layer is formed by a film, a laminating adhesive and/or a paint receiving layer.
11. The substrate sheet according to at least one of claims 1 to 10, characterized in that the stabilization layer comprises subregions arranged in the interior of the substrate sheet, in particular for stabilization of individual single sheets arranged in the substrate sheet.
12. The substrate sheet according to at least one of claims 1 to 11, characterized in that the substrate sheet is a paper sheet or a composite foil sheet (hybrid sheet), preferably with a layer sequence film/paper/foil or paper/foil/paper.

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