EP1839899B1 - Printed security element as control element - Google Patents

Description

For register-accurate printing of multiple print layers on carrier substrates control marks are necessary for the control of the printing process.

In particular, in the subsequent printing of optically active layers, such as surface structures, holograms, diffraction structures, diffraction structures, Kinegrammen and the like, a high register accuracy is necessary. The hologram cylinder has diffractive controls, which, however, must be matched to the particular reader used.
These controls are therefore clearly recognizable only by the respective, matched reader, other readers can not unambiguously and accurately identify these controls.

Subsequently, register-accurate printing with further security elements takes place in a further operation.

For further printing or further processing, such as packaging and the like, therefore, tax stamps are required, which are clearly and error-free recognizable by readers regardless of their setting. This is particularly important if the further printing is to be done, for example register accurate.

In this case, further control marks are imaged on a corresponding printing cylinder, and printed in-line and / or offline and / or in an additional operation on the carrier substrate.

Due to the necessity of producing a separate printing cylinder for the application of the control marks and to carry out a separate printing process, high costs are incurred.

According to the state of the art, it is customary in a further, separate working step (in a so-called insetter method) to print additional or further security features on the films provided with embossed structures. The achievable tolerances are according to the current state of the art +/- 0.2 to +/- 1 mm.

The object of the invention was to provide a method in which the register-accurate printing can be done without the additional effort and with improvement of the tolerance.

Under register-accurate security printing the significant improvement to the state of the art is required. According to the state of the art, a register-accurate pressure is defined with a tolerance of +/- 0.2 mm. Object of the invention is also to achieve an improvement in tolerance to +/- 0.1 mm or less.

The invention therefore relates to a method for register-accurate printing on carrier substrates which have, in particular, optically active layers, such as surface structures, holograms, diffraction structures, diffraction structures, kinegrams and the like, wherein diffractive control marks are applied to the carrier substrate and subsequently a further printing or further processing takes place. characterized in that for the further printing in the first printing step, a printing cylinder is provided which applies the control marks for the subsequent printing and at the same time has a corresponding security motif.

Thus, several functions can be fulfilled with the printing cylinder.

On the one hand, the inaccuracy of counterfeiting is increased by the register-accurate pressure in-line to the optically active structure.

Furthermore, the control marks applied to the cylinder simultaneously with the security motif serve to control further printing or as an aid to further working steps up to final assembly.

The printing cylinder for attaching the control marks is designed so that it has a print motif in register with a tolerance of at most +/- 10 microns to the subject of the optically active structure in addition to the control marks.
The controls must be selected and arranged according to the following process steps.

In order to increase the security against forgery of holograms, it is desirable to print, among other things, texts or images register-accurate (+/- 0.1 mm) to the surface structure.
For this to be realized, the produced hologram embossing cylinder must be measured accurately (0.01 mm). This occurs when the embossing cylinder is joined (for example by welding, gluing or the like) and adapted to a clamping cylinder.

Dimensions resulting from the individual repeat and the cylinder layout are only of a theoretical nature, since these dimensions change due to the production process of embossing cylinders with recombination (duplication of the individual repeat) and electroplating (production of the production shims).

In order to adapt the text or motif cylinder exactly to the embossing cylinder, it is necessary to precisely measure not only the printing width but also the printing length (circumference).
In order to determine the exact scope of the text or motif cylinder, details of shim thickness and grading (0.03 - 0.15) are still required.
The shim thickness is usually 50-250 μm, preferably 100-200 μm, particularly preferably 120-150 μm.

The grading results from parameters of the printing press, the order of operations, and the material used. With this printing cylinder thus produced, it is now possible in addition to texts; Motifs, symbols, etc. To increase the security against counterfeiting, also a wide variety of printing, cutting, stamping marks, etc. for the purpose of controlling subsequent processes right through to packaging.

Als Trägersubstrat kommen beispielsweise Trägerfolien vorzugsweise flexible Kunststofffolien, beispielsweise aus PI, PP, MOPP, PE, PPS, PEEK, PEK, PEI, PSU, PAEK, LCP, PEN, PBT, PET, PA, PC, COC, POM, ABS, PVC in Frage. Die Trägerfolien weisen vorzugsweise eine Dicke von 5 - 700 µm, bevorzugt 8 - 200 µm, besonders bevorzugt 12 - 50 µm auf.The calculation of the take-off length, that is of the nominal circumference, is done by the following formula: $${\mathrm{scope}}_{\mathrm{should}}=\left({\mathrm{scope}}_{\mathrm{is}}/\mathrm{\pi }+\mathrm{Shimdicke}\times \mathrm{2}+\mathrm{gradation}\times \mathrm{\pi }\right)\times \mathrm{material\; constant}\times \mathrm{Druckmaschinen\; correction\; factor}$$

For example, carrier foils are preferably flexible plastic foils, for example, PI, PP, MOPP, PE, PPS, PEEK, PEK, PEI, PSU, PAEK, LCP, PEN, PBT, PET, PA, PC, COC, POM, ABS, PVC in question. The carrier films preferably have a thickness of 5 to 700 .mu.m, preferably 8 to 200 .mu.m, more preferably 12 to 50 .mu.m.

The carrier substrate may be provided on one or both sides with a hot or cold seal adhesive or a self-adhesive coating or may be provided after the application of the surface structure and optionally after further coating steps.

Depending on the requirement, both functional and decorative layers can be used as printing or security motifs.

The security motif may be in the form of characters, patterns, lines, geometric figures, symbols, and the like.

In particular, the carrier substrate having the diffractive structures can be provided with a metallic or metallic appearing layer partially or completely, wherein these layers can be applied partially or completely by suitable known printing methods, metallization and demetallization methods.

The functional layers may, for example, have certain electrical, magnetic, chemical, physical and also optical properties.

To adjust electrical properties, such as conductivity, for example, graphite, carbon black, conductive organic or inorganic polymers. Metal pigments (for example, copper, aluminum, silver, gold, iron, chromium and the like), metal alloys such as copper-zinc or copper-aluminum or amorphous or crystalline ceramic pigments such as ITO and the like may be added. Furthermore, doped or non-doped semiconductors such as, for example, silicon, germanium or ion conductors such as amorphous or crystalline metal oxides or metal sulfides can also be used as an additive. Furthermore, polar or partially polar compounds such as surfactants or nonpolar compounds such as silicone additives or hygroscopic or non-hygroscopic salts can be used or added to adjust the electrical properties of the layer.

To adjust the magnetic properties, paramagnetic, diamagnetic and also ferromagnetic substances such as iron, nickel and cobalt or their compounds or salts (for example oxides or sulfides) can be used.

The optical properties of the layer can be visualized by visible dyes or pigments, luminescent dyes or pigments which fluoresce or phosphoresce in the visible, in the UV region or in the IR region, effect pigments, such as liquid crystals, pearlescent, bronzes and / or multilayers -Farbumschlagpigmente and heat-sensitive colors or pigments influence. These can be used in all possible combinations. In addition, phosphorescent pigments can also be used alone or in combination with other dyes and / or pigments.

Various properties can also be combined by adding various additives mentioned above. Thus, it is possible to use colored and / or conductive magnetic pigments. All mentioned conductive additives can be used.
Especially for the dyeing of magnetic pigments it is possible to use all known soluble and non-soluble dyes or pigments. Thus, for example, a brown magnetic ink can be adjusted to metallic, for example silvery, by adding metals in their color shade.

The film material thus produced is optionally suitable as a security element in data carriers, in particular value documents such as ID cards, banknotes or labels, seals and the like, but also as packaging material, for example in the pharmaceutical, electronics and / or food industry, for example in shape Blister foils, cartons, covers, foil packaging and the like.

For use as security elements, the substrates or film materials are preferably cut into strips or threads or patches, wherein the width of the strips or threads may preferably be 0.05-10 mm and the patches preferably have average widths or lengths of 0.3. 20 mm.

For use in or on packaging, the film material is preferably cut into strips, tapes, threads or patches, the width of which of the threads, strips or tapes being preferably 0.05-50 mm and the patches preferably have mean widths and lengths of 0.5-200mm.
A corresponding security thread or strip can also be used as edge reinforcement of packaging, documents of value and the like in the region of the edges but also, for example, as longitudinal or transverse reinforcement in the packaging or in the document of value, whereby in each case several threads or strips are at a defined distance from one another can be provided.

Claims (4)

1. Method for the accurate-register printing of carrier substrates which have optically active layers, such as surface structures, holograms, refractive structures, diffractive structures, kinegrams and the like, diffractive control marks being applied to the carrier substrate and further accurate-register printing or further processing then being carried out,
   characterized in that a printing cylinder is already provided in the first printing step for the further printing in the first printing step, which printing cylinder applies further control marks for the subsequent printing in addition to the diffractive control marks and simultaneously has a corresponding security motif.
2. Method according to Claim 1, characterized in that the security motif is present as a print having electrically conductive, magnetic and/or optical features.
3. Method according to either of Claims 1 and 2, characterized in that the circumference of the printing cylinder having the control marks and the security motif is calculated in accordance with the following formula: $${\mathrm{circumference}}_{\mathrm{desired}}=\left({\mathrm{circumference}}_{\mathrm{actual}}/\mathrm{\pi }+\mathrm{shim\; thickness\; x}\mathrm{2}+\mathrm{gradation\; x\; \pi }\right)\mathrm{x\; material\; constant\; x\; printing\; press\; correction\; factor}\mathrm{.}$$

   
4. Method according to Claim 3, characterized in that the shim thickness is 50 - 250 µm.