EP1616712A1 - Intaglio printing plates for producing security features, product made by means of said printing plates - Google Patents

Abstract

The rotary intaglio printing process is used on packaging for a wide variety of different items. Other printing processes may be used, including offset, flexographic printing, silkscreen or digital printing. The security marking may be read using a screen for a moire effect with phase shifts in the pattern or a Scrambled Indicia (RTM) system. The security and identification markings may be generated by a data file producing a pattern on printing plate attached to printing cylinder, or a printing structure may be directly formed on the cylinder. The pattern may be cut using a laser beam or an electron beam.

Description

Rotary intaglio printing plates for the production of security features, in particular with Moiree effects and / or Scrambled Indicia® processes for their production and products produced using these intaglio printing dies and their use

The invention relates to rotary gravure printing plates for the production of security features in the gravure printing method, which could previously be produced only by other printing processes, mainly offset, such as flexographic, screen or digital printing, and a process for their preparation and the products produced by this method using the intaglio printing plates according to the invention.
Security features in the context of the invention are, for example, security strips and threads for means of payment, such as banknotes, and other value documents, labels and tear strips for packaging and articles connected to them. To secure these packages and items such as picture and sound carriers, pharmaceuticals, electronic components, spare parts for the auto industry and the like, the invention is also suitable. Means of payment and value documents within the meaning of the invention may be bank notes, identification documents, checks, authorization cards, access cards and the like.

There are a variety of invisible security features, especially for packaging of sensitive goods, such as pharmaceuticals, foods, cosmetics, electronic components and the like known.

For example, an invisible security feature that operates on the Moiree phase shift method is known. In this case, a feature is applied in rasterized form, which is invisible for the time being and is only visible to the eye by overlaying or placing a grid foil (lens).

Furthermore, Scrambled Indica® are known, this feature is initially invisible to the naked eye, but can be made visible with the help of a lens.

If necessary, all these security features can also be individualized.

The described security features invisible to the naked eye have hitherto been accessible either only through format-related Roolen offset processes, digital printing (Xeikon, HP Indigo, the.factory) (inkjet) or by flexographic printing / letterpress printing (limited even in low-pressure but with low quality level).
The production of such security features in rotary gravure printing was previously not possible because necessary precision and fineness of the grid or lines could not be achieved with the known intaglio printing plates. (State of the art: The grid of the digital file is superimposed by the "machine grid" of the engraving machines .This destroys the security feature or significantly negatively influences the quality.

The object of the invention was to make the described security features accessible in particular rotary gravure printing methods.

The invention therefore rotative intaglio printing forms, characterized in that the corresponding applied in rotative gravure invisible security feature is generated as a data file, whereupon the rotary gravure form is imaged accordingly.

To produce the rotary gravure printing plate, a method is preferably used in which a corresponding cylinder is imaged using the laser or electron beam technology or surface-structured.

For this purpose, a corresponding data file is generated in a first step.

In order to produce a security feature which operates according to the moire-phase shift method, a raster area (1-bit) is generated from an 8-bit grayscale image in a first step. In this case, preferably a 30 to 120 grid is used, preferably 60 to 90, particularly preferably 70. The screen angle is preferably 30-60 °, particularly preferably 45 °.
The resolution can be 1016 to 5080 dpi, particularly preferably 2540 dpi. However, even higher resolutions are possible.

Subsequently, a feature (e.g., a logo, letters, symbols, and the like) is converted to a rasterized bitmap file (1 bit) using the same parameters, and the congruent grid area of the feature is now offset, preferably by about 0.1 to 0.3 mm.

The phase shift of the dot matrix now leads to a modification of the halftone dots.

To produce a Scrambled Indica® feature, the underlying color image is scanned by a scanner, e.g. B. Hell S 3300, decomposed into the primary colors cyan, magenta, yellow and black. Any spot or pantone colors can be edited in the same way as the primary colors (cyan <> blue).

Subsequently, the color separation to be protected is determined taking into account the information depth.
Each picture shows a different composition of the four primary colors. Matching the protective image, the color separation that contains the most color information is selected.

The other basic colors are now transferred unchanged by means of a known cylinder engraving machine such as Hell, Ohio or Dätwyler on the corresponding endless cylinder.

Depending on the information density (detail document), the grid widths range between 30 and 200 l / cm and preferably between 54 and 140 l / cm.

The color separation to be protected is reduced to a residual color strength of about 10 to 90%, preferably 30 to 60%, particularly preferably 30 to 40% and then transferred as described by means of a cylinder engraving machine.

For the security element, another cylinder is now generated.
This means that two superimposed rasters are not generated on one cylinder, which would create blurring, but instead transmit the rasters 1: 1 to the respective cylinder.
In the color separation to be protected, the feature to be hidden (logo, letter, symbol and the like) is included and converted into a pixel format with the help of RIP programs, for example Adobe Photoshop. The resolution is 300 - 5080 dpi, preferably 2540 - 5080 dpi. But there are also higher resolutions possible, 10600 dpi.
The conversion takes place in a Tiff bitmap format with exclusive black / white (1-bit) information, which is subsequently coated by means of a laser or electron beam imaging method, a laser or electron surface structuring or a laser ablation method (cylinder is coated with black protective coating). the image to be transferred is burned by laser in coating, followed by etching with Fe (3) chloride) is transferred.

The lenses necessary for the detection of the described security features can be generated and modified specifically for an application form, so that, for example, different lenses are available depending on the product or application. (more precisely describe lenses) The lenses are exposed with a conventional film exposure unit, eg DOLEV 2dry. In this case, a 30 to 120 grid is preferably used, preferably 60 to 90, particularly preferably 70. The resolution can be 1016 to 5080 dpi, particularly preferably 2540 dpi. However, even higher resolutions are possible. The grid widths move between 30 and 200 l / cm and preferably between 54 and 140 l / cm.

This increases the security against counterfeiting.

The image produced in this way is then exposed to a prepared cylinder in a corresponding exposure system.
For example, with the aid of a laser or electron beam on the cylinder, for example a gravure cylinder with a core of iron tube with wall thickness 20 mm, and the following layers: 5-7μm nickel layer, 300μm copper layer; existing photosensitive layer with the corresponding patterns, shapes, lines, letters in the form of the previously defined grid imaged, developed and etched. (or Daetwyler direct laser method on zinc) (or novel Hell-Xtrem®, Ohio-Transscribe @ engraving methods)

The coating of the cylinder is carried out in the usual way with a Kunststoffübertragungsrad, or by spraying, rolling, brushing, dipping, or by means of a curtain coating process, preferably in a layer thickness of 2-10 microns with a commercially available photosensitive composition, for example, LD 100, OHKA Kogyo Ltd ,

However, all other known and commercially available compositions are also suitable. Subsequently, the cylinder is provided with an overcoat with a layer thickness of 1 - 5 microns, for example with OC-40 (OHKA Kogyo Ltd), or with an analogous similar commercially available composition.

The development takes place after the exposure in the usual manner, for example, contactless with sodium carbonate (0.5% solution), this is usually followed by a cleaning process with water, after which the cylinder is dried.

But there are also all other known photo-development processes possible.

Furthermore, the corresponding gravure cylinder can also be imaged by the laser ablation process. In this case, an applied to the cylinder absorption layer is treated directly with the laser and evaporated. This creates an etchable mask. Such methods are, for example, the Scheppers-Ohio method or the Digilas method of the company Dätwyler.

Subsequent conventional etching process following the laser beam imaging reflects the image, patterns, shapes and the like defined by the laser beam imaging on the surface of the cylinder. The etching can be carried out in various ways, for example by means of a Fe (III) chloride solution or a Cu (II) chloride solution, if appropriate with the addition of HCl or H ₂ SO ₄ . If appropriate, commercially available and known additives for flank protection can also be added to the etching solution.

The duration of the action of the etchant depends on the etchant used and is for example when using a Cu-chloride solution with the addition of an acid about 90 - 2400 sec.

However, it is also possible to use an electrochemical etching method.

The cylinder looks blunt and visually dark after the etching process. By a surface treatment with electrolytic or chemical shining the impression structure can be refined and a brilliant surface can be produced.

The intaglio printing plates according to the invention are used for producing invisible security features which can only be visualized with the aid of a corresponding detector (lens) on carrier substrates.

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.

Furthermore, metal foils, for example Al, Cu, Sn, Ni, Fe or stainless steel foils with a thickness of 5-200 μm, preferably 5 to 80 μm, particularly preferably 5-50 μm, may also serve as the carrier substrate. The films can also be surface-treated, coated or laminated, for example, with plastics or painted.

Further, as carrier substrates also paper or composites with paper, for example, composites with plastics with a grammage 20-500 g / m ^2, preferably 40-200 g / m ^2. be used.

Further, as carrier substrates, woven or nonwoven fabrics, such as continuous fiber webs, staple fiber webs and the like, which may be needled or calendered, may be used. Preferably such fabrics or webs of plastics, such as PP, PET, PA, PPS and the like, but it can also be woven or nonwovens of natural, optionally treated fibers, such as viscose fiber webs are used. The fabrics or nonwovens used have a basis weight of about 20 g / m ² to 500 g / m ² . Optionally, these fabrics or nonwovens may be surface treated.

The printed carrier substrates produced by means of the rotative intaglio printing plates according to the invention are therefore, if appropriate, suitable as security features in data carriers, in particular value documents such as identity cards, cards, banknotes or labels, seals and the like, but also as packaging material, for example in the pharmaceutical, electronics and / or or food industry, For example, in the form blister sheets, cartons, covers, film packaging and the like.

For use as security features, the substrates or, like 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 2. 30 mm.

For use in or on packaging, the film material is preferably cut into strips, tapes, threads or patches, wherein the width of the threads, strips or tapes is preferably 0.05-50 mm and the patches are preferably average widths and lengths of 2 -30 mm.

However, it is also possible to print the described security features directly on primary packaging, such as cardboard, foils, aluminum, blisters and the like, or directly on value documents.

Claims (15)

Rotative intaglio printing forms, characterized in that the corresponding invisible security feature to be applied in rotary gravure printing is generated as a data file, whereupon the rotative intaglio printing plate is correspondingly imaged or directly surface-structured. Rotary intaglio printing plates according to claim 1, characterized in that the invisible security feature is a feature that works according to the Moiree-Phasenshift method or is a Scrambled Indicia®. Rotary gravure printing forms according to one of claims 1 to 2, characterized in that the rotary gravure form is imaged by means of a laser process. Rotary gravure printing forms according to one of claims 1 - 3, characterized in that the rotary gravure printing plate is imaged by means of an electron beam method. Rotary gravure printing forms according to one of claims 1 - 3, characterized in that the rotary gravure form is imaged by means of laser surface structuring. Rotary gravure printing forms according to one of claims 1 - 3, characterized in that the rotary gravure form is imaged by means of electron beam surface structuring. Rotary gravure printing forms according to one of claims 1 - 3, characterized in that the rotary gravure form is imaged by means of laser direct method on zinc. Rotary gravure printing forms according to one of claims 1 - 3, characterized in that the rotary gravure form is imaged by means of the Hell-Xtrem® method or Ohio-Transscribe® method. Use of the rotary gravure printing method according to one of claims 1 to 9 for the production of Moiree phase shift safety features, or of Scrambeld Indicia® Use according to claim 10, characterized in that the Moiree phase shift safety features or Scrambeld Indicia® are applied to a carrier substrate, which is then applied to a package or a document of value or at least partially embedded in this. Use according to claim 10, characterized in that the moiree phase shift safety features, or by Scrambeld Indicia® are applied directly to a document of value or a primary packaging. Rotary gravure printing method for producing moiree phase shift security features or scrambled indicia®, characterized in that the security feature using the rotative intaglio printing forms are prepared according to one of claims 1 to 9. Moiree phase shift security features or Scrambled Indicia®, characterized in that both the Moiree-Phasenshift security features or Scrambled Indicia® and the necessary for detection lenses or rasters are prepared by a method according to claim 13. Packaging or value documents, characterized in that they have Moiree phase shift security feature or a Scrambeld Indicia® feature according to claim 14. Packaging or value documents, characterized in that it has a security feature according to claim 14, which is applied to the value document or the packaging and / or at least partially embedded.