EP0537439A1 - Security element - Google Patents

Abstract

A security element for authenticating a substrate (1) has a pattern consisting of optical diffraction elements (4) embossed in a support material of plastic and of unembossed neutral areas (5). On the embossing side of the support material, a reflecting layer covers only areas with relief structures of the diffraction elements (4), whereas the neutral areas (5) lying between them are free of the reflecting layer and hence are non-reflecting. If the security element is bonded to the substrate (1) as a stamp (3) and if the support material is transparent, partial images (6) of a feature (2) on the substrate (1), masked by the stamp (3), are identifiable through the neutral areas (5). <IMAGE>

Description

The invention relates to a security element of the type mentioned in the preamble of claim 1 and to a method for producing such a security element.

Such security elements are suitable, for example, for securing a glued-on photograph on an identity card, the security element designed as a brand covering both a partial area of the photograph and a partial area of the ID card.

European patent application EP-A 401 466 describes such a security element which has a full-surface reflection layer and shows a pattern composed of surfaces with embossed relief structures and non-embossed surfaces arranged between them. When the security element is viewed visually, the bright reflections on the unembossed surfaces disturb the full color development of the light diffracted at the relief structures.

European patent EP 169 326 describes a device for the production of matrices with which the microscopic relief structures are embossed, for example, in plastic supports aluminized on one side. The improved device from European patent application EP-A 330 738 enables the production of the matrices necessary for embossing the relief structures, which have partial areas with at least one dimension less than 0.3 mm.

From European patent application EP-A 253 089 it is known to interrupt the reflection layer in the area of the relief structures in a predetermined pattern in order to achieve good adhesion between a support of the relief structures and a protective layer covering them.

European patent application EP-A 439 092 describes the use of the security element with diffraction structures that are partially covered with the reflection layer in a grid-like manner, for securing ID cards, the features of the ID card covered by the security element being recognizable through non-reflecting partial surfaces despite clouding through the grid.

The invention has for its object to provide a security element with a pattern of diffraction optically effective relief structures and non-embossed neutral areas, in which the visual observation of the pattern is not disturbed by the light reflected from the neutral areas, and to find an inexpensive manufacturing process for it.

According to the invention, the stated object is achieved by the features of claims 1, 9 and 11. Advantageous refinements result from the dependent claims.

Figur 1

einen Ausweis mit einem Sicherheitselement,

Figur 2

eine Marke im Querschnitt,

Figuren 3a bis 3d

das Abdecken von Reliefstrukturen mit einem Schutzlack mittels eines drucktechnischen Verfahrens,

Figuren 4a bis 4c

das Abdecken der Reliefstrukturen mit dem Schutzlack mit einem Tiefdruckverfahren,

Figuren 5a bis 5d

das Abdecken der Reliefstrukturen mit dem Schutzlack mit einem Hochdruckverfahren,

Figur 6

die Marken auf einem Trägerband,

Figuren 7a und 7b

die Herstellung einer Prägematrize und

Figur 8

die Prägematrize mit erhabenen Beugungselementen.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.
It shows:

Figure 1

an ID card with a security element,

Figure 2

a brand in cross-section,

Figures 3a to 3d

covering relief structures with a protective varnish using a printing process,

Figures 4a to 4c

covering the relief structures with the protective lacquer using a gravure printing process,

Figures 5a to 5d

covering the relief structures with the protective lacquer using a high-pressure process,

Figure 6

the stamps on a carrier tape,

Figures 7a and 7b

the production of an embossing die and

Figure 8

the embossing die with raised diffraction elements.

In FIG. 1, 1 means a substrate made of paper, plastic, metal and the like, on the surface of which a feature 2 is arranged. A mark 3 made of plastic covers adjacent partial surfaces of the substrate 1 and the feature 2 as a security element, the mark 3 being glued to the feature 2 with one partial area and to the substrate 1 with the other partial area. The substrate 1 can be an identification document, the feature 2 being a photograph of the holder, a signature made before the application of the label 3 or another identification.

The mark 3 has a pattern which is composed of diffraction-optically active surfaces with diffraction elements 4 and neutral areas 5. The diffraction elements 4 diffract the incident ambient light in reflection and produce a characteristic color image that changes when the substrate 1 is tilted. The neutral areas 5 do not reflect; for example, they are absorbent or transparent. If the neutral areas 5 are transparent, only a slight reflection on the surface of the mark 3 is noticeable in the areas 5 because of the jump in the refractive index of the media (air-plastic), but neither the color image nor the viewing of the substrate visible at this point 1 or feature 2 interferes with the mark 3.

The security element is particularly advantageous when viewed visually if the diffraction elements 4 are, for example, linear and form filigree patterns on the security element. These patterns have the advantage that the feature 2 lying under the mark is easily recognizable, especially if the lines of the diffraction elements 4 are as narrow as possible. The line widths can be less than 0.5 mm, for example 0.1 mm, 0.05 mm or even narrower. A dot pattern or a pattern made up of dots is also conceivable, the diameter of the dot-shaped diffraction elements 4 corresponding approximately to the line widths above. Line widths from about 25 microns can be achieved with the means described in EP-A 330 738 with the title "Document" by Antes et al. are described and their text expressly belongs to this description. An individual diffraction element 4 can be generated in each point or line segment, which differs in its parameters, spatial frequency and grating profile, from the neighboring points or line segments. The change of the parameters from one diffraction element 4 to the other can be as z. B. graphically designed means to increase security.

To make it possible to identify an untracked feature 2, it is advantageous to design the pattern on the security element such that the sum of the areas of the neutral areas 5 lying between the diffraction elements 4 is greater than the sum of the areas of the diffraction elements 4.

The security element has the advantage that the diffraction elements 4 stand out very conspicuously due to the reflection of the diffracted light from the faint neutral areas 5, at which no light is reflected, which mixes with the play of colors of the diffracted light and the brilliance of the diffraction elements 4 can decrease. Since the partial images 6 of the feature 2 lying underneath them can be seen through the neutral areas 5 and which must produce a complete image of the feature 2 with the partial images 7 not covered by the mark 3, the adhesive label 3 is also suitable as a security element for Authentication of the feature 2, which is not only characterized by the high visibility of the diffraction elements 4 and by the transparency in the neutral areas 5, but also offers a visually verifiable, high security against forgery of the authentication of the feature 2.

Is the substrate 1 made of plastic, such as. B. with a credit card can be a brilliant security element Diffraction-optical identification mark 8 with such a pattern can also be generated directly in the surface of the substrate 1 without the detour via a glued-on mark 3.

FIG. 2 shows a cross section through the ID card with the label 3 glued onto the substrate 1 as a security element. A layered composite is shown as an example, which is described in European patent application EP-A 401 466 with the title "Layered composite with diffraction structures" by the same applicant and the text of which expressly belongs to the present description.

A carrier 10 made of plastic for the diffraction elements 4 is enclosed between the substrate 1 and a stabilization layer 9 made of polyester. A lacquer layer 11 provides good adhesion between the stabilization layer 9 and the carrier 10. The diffraction elements 4 are embossed into the carrier 10 as microscopic relief structures 12. A protective layer 13 covers both the relief structures 12 covered with a reflective layer 14 and the non-embossed and non-reflective neutral regions 5 of the carrier 10. An adhesive layer 15 applied to the protective layer 13 firmly connects the mark 3 (FIG. 1) to the substrate 1, the adhesive connection not being able to be released without destroying the security element.

Advantageously, the carrier 10 and the protective layer 13 are made of the same material, so that the carrier 10 and the protective layer 13 can be connected particularly intimately in the neutral areas 5, so that no weak point is formed at the joint and the protective layer 13 for molding the Relief structures 12 can be removed without destroying them. If the carrier 10 and the protective layer 13 are made of the same clear material, an undisturbed carrier surface 16 present in the unembossed neutral areas 5 is invisible. The carrier surface 16 is therefore shown in dashed lines in the drawing. The neutral areas 5 therefore remain completely clearly transparent and interfere with the visibility of the brand 3 lying feature 2 (Figure 1) not. However, the carrier 10 and the protective layer 13 can also be colored differently. Instead of the layer composite, a solid film, for example made of PVC, can also be used as a carrier material 17.

If the mark 3 is to be used for gluing onto the substrate 1, transparent or even colorless materials are advantageously used for the protective layer 13, for the adhesive layer 15 and for the carrier material 17, so that the feature 2 (FIG. 1) is visible through the neutral areas 5 remains.

In another embodiment, the carrier 10 itself is stable enough so that the stabilization layer 9 and the lacquer layer 11 are unnecessary.

The production of the security feature is characterized by a few characteristic process steps, which can be recognized from the production processes listed as examples. For example, in comparison to the prior art (EP-A 401 466), only a few additional method steps have to be inserted in the following, which, however, are designed differently, as described below. Each of these methods has its advantages.

FIGS. 3a to 3d, 4a to 4c and 5a to 5d show examples of the step-by-step production of a raw material in band form for marks 3 (FIG. 1) with the security element. To show the successive steps in the method, these drawings are rotated by 180 ° with respect to FIG. 2. The strip shape enables the use of a continuous process and is therefore suitable for inexpensive mass production.

In FIG. 3a, the band-shaped carrier material 17 has, for example, the stabilization layer 9 and the carrier 10, which are connected to the lacquer layer 11 (FIG. 2). The carrier material 17 is on the stabilization layer 9 opposite side, the embossing side, covered with a reflective layer 14 over the entire surface. As a reflective layer 14 z. B. evaporated aluminum layers are known, the thickness of which is only a fraction of a micrometer.

The carrier material 17 is drawn off as a tape from a supply roll, not shown here, and successively reaches the various processing zones, in which the marks 3 (FIG. 1) with the security feature are completed step by step.

Procedure 1:

In the first step (Figure 3a) using z. B. heated embossing matrices, the microscopic relief structure 12 is embossed in the pattern of the security element into an embossing side 18 of the carrier material 17 characterized by the reflective layer 14. One of the unembossed neutral regions 5 is enclosed between two diffraction elements 4 and 4 '.

In the second step (FIG. 3b), in the register of the patterns of the diffraction elements 4 (= "register"), a protective lacquer 19 is applied to the embossed diffraction elements 4 by means of a printing process, which precisely covers the reflective layer 14 on the surfaces of the diffraction elements 4 and that Leave layer 14 free and uncovered on the neutral areas 5. The protective lacquer 19 is, for example, clearly transparent or colored and only transparent to light from a predetermined region of the spectrum.

The tape of the carrier material 17 is then drawn through a chemical bath. In the bathroom, the exposed reflective layer 14 on the neutral areas 5 is removed. If the reflective layer 14 consists of aluminum, dilute sodium hydroxide solution is suitable as a chemical bath, for example.

After washing and drying, the carrier material 17 has the structure shown in FIG. 3c. Only in the area of the diffraction elements 4, 4 'is that on the embossed relief structures 12 applied reflective layer 14 is present and covered with the protective lacquer 19. The unembossed neutral regions 5 lying between the diffraction elements 4, 4 'are no longer covered with the reflective layer 14, the unembossed carrier surface 16 of the carrier material 17 being exposed.

In the last working step, the preliminary material for brands shown in FIG. 3d is produced, whereby first the protective layer 13 is applied over the entire surface to the carrier material 17 on the embossing side 18 (FIG. 3a) and finally the adhesive layer 15 is applied.

The adhesive layer 15 can also be omitted if the adhesive is applied to one of the two adhesive partners 1, 3 immediately before the label 3 (FIG. 1) is attached to the substrate 1 (FIG. 1) or the protective layer 13 is designed as an adhesive layer 15.

This method has the advantage that the embossing matrices used to produce diffraction-optical patterns according to the prior art can also be used to generate the new security elements, so that no new embossing matrices have to be produced.

Procedure 2:

The carrier material 17 embossed in FIG. 4a through the reflective layer 14 has been embossed with raised embossed structures by means of an embossing die described below. As a result, the relief structures 12 embossed into the carrier 10 (FIG. 2) are a predetermined distance A into the carrier material 17, i. H. lowered under the carrier surface 16, with depressions 21 being formed. The distance A is measured between the surface of the carrier material 17 and the tips 20 of the relief structure 12 closest to it.

For example, this distance A is approximately 1 μm to 5 μm, while the relief structure 12 has height differences B of 1 μm or owns less. The relief structures 12 are embossed on the base of the depressions 21 and can therefore also have height differences B of more than 1 μm. As a result, the carrier material 17 in FIG. 4a has a mesa structure, the unembossed areas 5 representing the plateau and the depressions 21 with the relief structures 12 representing the valleys.

The application of the protective lacquer 19 shown in FIG. 4b takes place during the passage of the carrier material 17 through an application unit 22, 23 known in the printing industry for gravure printing. The carrier material 17 moves in a transport direction 24 from the roller mill 22 to the doctor blade 23 from e.g. B. plastic or rubber. The stripping knife 23 is arranged above the carrier material 17, the cutting edge of the stripping knife 23 being able to slide slightly resiliently on the reflecting layer 14 over the entire width of the carrier material 17 for stripping off the unnecessary protective lacquer 19.

The protective lacquer 19 is evenly distributed on the reflective layer 14 during the passage of the carrier material 17. By selecting the suitable properties of the protective lacquer 19, such as the viscosity, the wetting, etc., the numerical values of which are determined by tests, the protective lacquer 19 in particular also fills the depressions 21 and covers the relief structures 12. The stripping knife 23 strips the protective lacquer 19 present on the non-embossed neutral areas 5 from the reflective layer 14, so that only in the recesses 21 the protective lacquer 19 remains, which reflects the reflective layer 14 of the diffraction elements 4 before the action of the chemical bath for removing the reflective layer 14 protects.

Following the drying of the protective lacquer 19, the tape of the carrier material 17 is drawn through the chemical bath as in method 1 and the exposed reflective layer 14 is removed in the regions 5. FIG. 4c shows the pre-finished material as an example, in which the reflective layer 14 has remained only on the diffraction elements 4. Only the full area is on the carrier material 17 Protective layer 13 is present.

This method has the advantage that no precise work is required when applying the protective lacquer 19, since this results automatically and with great precision. It is even possible to emboss and apply the protective layer 13 and the protective lacquer 19 at different production sites without the accuracy of the delimitation of the reflective layers 14 on the diffraction elements 4 being affected.

The arrangement of the relief structures 12 on the base of the depressions 21 in the carrier material 17 is advantageous since the greatest possible protection of the relief structures 12 (FIG. 4b) is achieved when the diffraction elements 4 are covered with the protective lacquer 19. For the sake of completeness, it is mentioned that the protective lacquer 19 can also be applied to the carrier material 17 with the mesa structure according to method 1.

Procedure 3:

The security elements can also be produced with a starting material as carrier material 17 which, as in FIG. 5a, has no reflective layer 14 (FIG. 3a) on the embossing side 18. As in method 2, the diffraction elements 4 and the depressions 21 are produced in the carrier material 17 by means of the embossing die with raised embossing structures.

After embossing the carrier material 17, a washable material is applied as a separating layer 25 according to EP-A 253 089 by means of a printing unit known from high pressure, which is shown here only with its application roller 26, on the surfaces of the unembossed neutral areas 5 of FIG. 5b. The application roller 26 rolls on the embossed side 18 of the carrier material 17 and covers the raised neutral areas 5 with the separating layer 25. The viscosity and the application thickness of the washable material is selected such that the washable material does not fill the depressions 21 and the relief structures 12 ( Figure 2) dirty. The interface 25 therefore only covers the neutral areas 5 and the relief structures 12 embossed in the depressions 21 remain free.

As can be seen from FIG. 5c, the carrier material 17, which is partially covered with the separating layer 25, is then coated with the reflective layer 14 both on the relief structures 12 in the depressions 21 and on the separating layer 25.

After a washing process, which removes the washable material of the separating layer 25 together with the reflective layer 14 applied directly to it, in FIG. 5d the primary material only has the reflective layer 14 in the diffraction elements 4, while in the neutral regions 5 the carrier material 17 exposed. Finally, the carrier material 17 is coated over its entire area with the protective layer 13, the depressions 21 being filled with the material of the protective layer 13.

The advantage of this process is a shorter throughput time in the production of the primary material, since the process step for applying the protective lacquer 19 (FIG. 4c) is omitted.

A combination of individual steps from the three methods is also possible. In particular, starting from an embossed carrier material 17 shown in FIG. 5a without a reflective layer 14 (FIG. 4b), the protective lacquer 19 can be applied by means of the printing process as in FIG. 3b or with the process shown in FIG. 4b. The carrier material 17 and the protective lacquer 19 advantageously differ in their refractive index in FIG. 4c. The carrier material 17 has a value of less than 1.5 in the refractive index, while the protective lacquer 19 above the diffraction elements 4 has a refractive index above 1.55. The jump in the refractive index at the boundary layer between the carrier material 17 and the protective lacquer 19 causes a strong reflection of the light falling through the carrier material 17 onto the diffraction elements 4, so that this boundary layer forms the reflective layer 14 and has the same effect. The absence of the metallic reflective Layer 14 also causes a strong, non-detachable connection between the layers in the diffraction elements 4.

A radiation-curable protective lacquer 19 has the advantage that when the protective lacquer 19 hardens in the recesses 21 (FIG. 5a), a very robust and heat-stable base is formed, which has the precisely shaped relief structures 12 (FIG. 2) in the diffraction elements 4. The marks 3 (FIG. 1) made from such a raw material withstand the heat required when the marks 3 are hot-glued or overlaminated, even without a stabilizing layer 9 (FIG. 2).

Advantageously, the carrier material 17 is transparent and at least the protective lacquer 19 (FIG. 3b) or the protective layer 13 is colored dark or even black, since the viewer can recognize the identifier 8 as a strikingly brilliant filigree pattern, e.g. B. as fine lines against a dark background. If the reflective layer 14 is not applied in register, besides the linear diffraction structures 4, reflective, non-diffractive surfaces can be easily recognized by the unarmed eye.

The security element can be used for authenticity detection of documents, banknotes and other objects. The pattern of the security element and the features 2 lying under the mark 3, such as image or writing elements printed on the substrate 1 or a watermark in the substrate 1, can also be recognized by the layperson with the unarmed eye, if the protective layer apart from the reflective layer 14 13 and the carrier material 17 are transparent. Such a quasi-transparent security element shows the fine filigree patterns from the diffraction elements 4 and, depending on the incidence of light and the viewing direction, can show a brilliant play of colors without the recognizability of the image or writing elements suffering through the clear neutral areas 5.

The quasi-transparent security element can be used to advantage partial or total coverage of the substrate 1 to be protected against forgery and its features 2 are used. Examples of such substrates 1 include personal identification cards with imprint and photo of the holder. The graphic pattern of the mark 3 covers the features 2 with the fine lines or line elements whose relief structure 12 act as diffraction elements 4. Because of the high light diffraction efficiency of the diffraction elements 4, a small area fraction of the diffraction elements 4 is sufficient so that recognition of the information on the substrate 1 through the neutral regions 5 is not impaired.

The linear diffraction elements 4 advantageously have changing spatial frequencies and profile shapes along the lines, so that the visual impression changes along the lines in a predetermined manner when the viewing conditions are changed, for example by rotating or tilting the substrate 1. An attempt to replace the features 2 located under the security element destroys the security element. Also falsifying the ID card, e.g. B. by assembling pieces of several real ID cards, is easily recognizable, since the fine lines of the diffraction elements shifted at seams or continue broken in the line. By tilting the substrate with the help of the obvious diffraction effects, even laypersons can easily check whether the fine diffraction elements 4 covering the information are intact, e.g. B. by checking whether the diffraction effects of the diffraction elements 4 along the fine lines change abruptly or not.

If the carrier material 17 is stiff enough, the ID cards in credit card format can be punched directly from the primary material. The pattern of the security element forms the identifier 8 (Figure 1) and serves z. B. as an optical eye-catcher. It is advantageous to use transparent or even colorless materials for the protective layer 13, the carrier material 17 and any protective lacquer 19, since the identifier 8 (FIG. 1) from both sides of the identification card is visible.

According to FIG. 6, the strip-like primary material can be processed, for example, into a branded roll 27 in a separate operation. This is particularly indicated if the marks 3 are made very thin (about 15 µm to 40 µm) for technical reasons. The patterns of the security elements regularly arranged on the primary material can be punched out as marks 3, and the stabilization layer 9 can be glued to a carrier film 28 made of paper or plastic with a cold adhesive. When a document or ID is secured, the mark 3 is pulled off the carrier film 28 and glued onto the substrate 1 (FIG. 1) and the feature 2 (FIG. 1).

The embossing matrices with raised embossing structures for producing the depressions 21 (FIG. 4a) and the relief structures 12 embossed at the base of the depressions (FIG. 4a) can be produced with the aid of the numerically controlled device described in EP-A 330 738, a first in Master structure 29 of the embossing die shown in FIG. 7a is produced.

The master structure 29 is fastened on a structure carrier 30. As soon as the master structure 29 is imprinted on one side with the microscopic relief structures 12 of the pattern, it is removed together with the structure carrier 30 from the device for coating with a photoresist 31. The positive-working photoresist 31 is applied in a layer thickness between 1 to 10 μm over the relief structures 12 of the diffraction elements 4, 4 'and over the neutral areas 5 of the exposed master structure 29 without destroying the embossed relief structures 12. The layer thickness of the photoresist 31 determines the height of the later embossed structures and corresponds at least to the distance A (FIG. 4a).

In a second pass, the device exposes the photoresist 31 with a write beam 32 through the structure carrier 30 of the master structure 29, the write beam 32 using of the same control program is controlled via the surfaces of the diffraction elements 4, 4 'and exposes the photoresist 31. The method has the advantage that the photoresist 31 is exposed with great registration accuracy within limits 33 above the diffraction elements 4, 4 ', since the structure carrier 30 can be repositioned precisely in the device by means of pins.

After the development of the photoresist 31, a master mold 34 from the master structure 29 remains in FIG. 7b, which only has the photoresist 31 on the unembossed surfaces located between the surfaces of the diffraction elements 4, 4 '. For example, a metal layer 35 is deposited on the surface of the master mold 34 using a galvanic process. The metal layer 35 consists, for. B. made of nickel and is an exact negative of the master form 34th

The embossing die can also be produced with a negative-working photoresist 31 if the photoresist 31 is exposed in the unembossed regions 5.

After the separation, the metal layer 35 forms an embossing die 36 with raised embossed structures 37 shown in FIG. 8, which can be used for embossing the carrier material 17.

The embossing dies 36 have the advantage that the relief structures 12 (FIG. 4a) are produced in the depressions 21 (FIG. 4a) during the embossing. This enables the use of the inexpensive methods 2 and 3 described above, which can be used in particular for the filigree patterns.

Claims (12)

Security element with a visually visible pattern of optical diffraction elements (4, 4 ') with microscopic relief structures (12) embossed on one side into a carrier material (17) made of plastic and with a reflective layer (partially covering the embossed side (18) of the carrier material (17) 14), characterized in that the reflective layer (14) only covers the embossed relief structures (12) and that the unembossed neutral areas (5) lying between the diffraction elements (4, 4 ') are not reflective. Security element according to claim 1, characterized in that to protect the diffraction elements (4, 4 ') the embossed side (18) is covered over the entire surface with a transparent protective layer (13) which covers the reflective layer (14) over the relief structures (12) and neutral areas (5), and that a carrier (10) of the relief structures (12) and the protective layer (13) consist of the same material. Security element according to claim 1 or 2, characterized in that the carrier material (17) is transparent, so that a pattern formed from the diffraction elements (4, 4 ') and the neutral regions (5) can be viewed through the carrier material (17). Security element according to Claim 3, characterized in that the carrier material (17) is designed for gluing to a substrate (1) and that an adhesive layer (15) applied to the entire surface of the embossing side (18) is transparent, so that features (2) on the substrate (1) remain visible through the neutral areas (5). Security element according to one of claims 1 to 4, characterized in that the sum of the areas of the neutral regions (5) lying between the diffraction elements (4, 4 ') is greater than the sum of the areas of the diffraction elements (4, 4'). Security element according to claim 5, characterized in that the diffraction elements (4, 4 ') have at least one dimension smaller than 0.5 mm and form a fine filigree pattern. Security element according to one of claims 1 to 6, characterized in that the diffraction elements (4, 4 ') at least one micrometer below a carrier surface (16) determined by the surfaces of the unembossed neutral areas (5) in depressions (21) of the carrier material (17 ) are arranged. Security element according to Claim 7, characterized in that the depressions (21) are filled with a protective lacquer (19) hardened by radiation. Embossing die for embossing security elements according to claim 6 or 7, characterized in that to produce the depressions (21) in the carrier material (17) the microscopic relief structures (12) for the diffraction elements (4, 4 ') as embossing structures (37) for the neutral areas (5) project certain level. Method for producing a security element on a carrier material (17) made of plastic, with diffraction elements (4, 4 ') made of microscopic relief structures (12) embossed through a reflective layer (14) and with neutral ones lying between the diffraction elements (4, 4') Areas (5), characterized in that after the embossing of the carrier material (17) only the surfaces of the embossed diffraction elements (4, 4 ') on the embossing side (18) are covered with a protective lacquer (19) and the neutral areas (5) Remain essentially free that the reflective layer (14) is removed in the neutral areas (5) and that at least one protective layer (13) is applied to the entire surface of the carrier material (17) on the embossed side (18). A method according to claim 10, characterized in that during embossing depressions (21) are created with the relief structures (12) in the surface of the carrier material (17), that the protective lacquer (19) is applied over the entire surface on the embossing side (18) and that Expose the reflective layer (14) in the neutral areas (5), remove the protective lacquer (19) by means of a doctor knife (23) and fill the depressions (21). Method for producing a security element on a carrier material (17) made of plastic, with embossed diffraction elements (4, 4 ') from microscopic relief structures (12) and with neutral areas (5) lying between the diffraction elements (4, 4'), characterized in that that an embossing die (36) with raised embossing structures (37) is used for embossing the carrier material (17), that the unembossed neutral areas (5) are covered with a separating layer (25) made of a washable material, that the relief structures (12) and the surfaces of the separating layer (25) are covered with a reflective layer (14), that the separating layer (25) is removed together with the reflecting layer (14) on the neutral areas (5) and that a protective layer (13) is applied to the entire surface Carrier material (17) is applied.

Images