OA16523A - Method for producing a multilayer data carrier and data carrier produced by said method. - Google Patents

Abstract

The invention relates to a method for producing a multilayer data carrier comprising a first layer which is made of plastic and has an upper face on which an opaque layer partially covering said upper face, for example a metal layer, is arranged. The data carrier has a second layer made of plastic which is disposed on the first layer and is transparent at least in a sub-region of the metal layer. The metal layer is partially removed by a laser to such an extent that the metal layer has at least one break. The metal layer is preferably laminated between the first and the second plastic layers.

Description

Method for Producing a Multilayer Data Carrier and

Data Carrier Produced by said Method

TECHNICAL FIELD

The invention relates to a method according to the preamble of claim 1.

In order to protect data carriers, for example identity cards, passports, driver's licenses, bank cards etc. having personalized data, security features are variously used. A very wide variety of security features for protecting the blank card without personalized data are known from the prior art. Often, however, it is the case that the forger does not forge a complété card but modifies or replaces the personalized data (photograph, date of birth, signature, name, etc.) on an e.g. stolen card. The protection of these personalized data is therefore very important. Techniques known from the prior art for protecting such data are, for example, the personalization of a second image in a lens structure, in such a way that the image is only visible at a particular observation angle. Another possibility for introducing a second image is to introduce a matrix image into the card by perforating the card. These production methods are relatively elaborate and require spécial devices during the card production (lens structure) or spécial machines for introducing the second image. The présent invention provides a way in which the personalization can be protected in a straightforward way without additional machines.

PRIOR ART

EP 1691 989 B1 discloses a data carrier which comprises a métal layer that is arranged between two translucent cover layers (light transmittance less than 10%). A watermark effect is intended to be created by ablation of the métal layer using a laser beam.

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EP 2 109 014 Al discloses a so-called overlay of laserable polycarbonate with a holographie layer on one side. The holographie layer can be metallized and partially ablated using a laser.

WO 2009/139800 discloses a security document comprising a metallized sheet, which is laminated surface-wide between transparent layers. A large part of the sheet is modified/printed in order to form the card background. A window of the sheet is left unmodified. After manufacture of the card, an image which is visible from the front side and rear side of the card is introduced into this window by means of laser ablation.

EP 0 420 261 relates to a method for producing a sériés of data carriers comprising holograms, in which the holograms are individualized by partial destruction or modification of the diffraction structures.

SUMMARY OF THE INVENTION

It is an object of the présent invention to provide a method for producing a data carrier which is protected even better against unauthorized modifications. The data carrier is nevertheless intended to be produced economically. The object is achieved according to claim 1.

The invention relates in particular to a multilayer data carrier of thermoplastic (for example polycarbonate, PVC, PET-G). According to one refinement of the invention, a preferably metallized thin layer is applied partially onto one of the layers. This metallized layer may for example be vapor deposited, applied by hot stamping or laminated together with a carrier layer (for example PET) between two layers of the data carrier. The metallized layer is advantageously thinner than 4 pm, in

- 3 the idéal case thinner than 1 pm. If it is laminated together with a carrier layer, the carrier should be no thicker than 50 pm, in the idéal case about 20 pm or thinner. The metallized layer may contain holographie diffraction structures. The metallized layer consists, for example, of aluminum, although other metals may be envisioned, for example titanium. The techniques for applying the métal layer onto a thermoplastic sheet are known to the person skilled in the art. The thermoplastic sheet is advantageously thicker than 50 pm, in the idéal case 100 pm or thicker.

The layer with the partially applied métal layer is then laminated together with the further layers of the cards to form a card body. In this case, the layer with the applied métal is covered with at least one further transparent layer. The layer onto which the métal is applied may be either transparent or opaque.

During personalization of the card, that is to say when writing the cardholder's data onto the card, the métal layer is then partially ablated, i.e. evaporated, using a laser. At the positions where the laser strikes the métal layer, the métal sheet evaporates and a recess is formed in the métal. Text or matrix images can therefore be written into the métal sheet using the laser. For this process, it is possible to use the same type of laser as is employed for the data carrier personalization known from the prior art (laser marking by means of blackening). It is, however, also possible to use a laser with a different wavelength.

When the métal layer is evaporated, the sheet below the métal layer is visible through the gap left in the métal sheet. Depending on whether this sheet is transparent or opaque, the image formed in the métal layer is optimally visible in transparent view (in the case of a transparent sheet) or direct view (in the case of an j/”' » *

- 4 opaque sheet). Owing to the reflection behavior of the métal layer, the image can be seen in direct view as positive (dark) or négative (light) depending on the viewing angle.

According to a refinement of the invention, the sheet is printed in a color before application of the métal layer, so that the color is visible through the gaps in the métal layer after the ablation of the métal layer and provides a spécial effect.

According to a refinement of the invention, the métal layer is introduced or applied, respectively, onto or into a transparent window in the data carrier, so that the ablated image is visible in transparent view but the rest of the data carrier comprises an opaque core layer.

According to a refinement of the invention, a thin opaque plastic layer having a spécial additive is used instead of a métal layer, this additive modifying the opaque plastic layer during the exposure in such a way that it becomes transparent or at least translucent. The additive is, for example, a pigment which is destroyed during the exposure to a laser. Such pigments are known to the person skilled in the art. Instead of a pigmented plastic, it is possible to use a semicrystalline opaque plastic in which the macromolecules arranged in crystallites are converted into an amorphous and transparent structure by the heat input of the laser radiation.

The opaque plastic layer may, for example, be introduced into the card structure as a co-extruded sheet or as a separate sheet by the known techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

- 5 Exemplary embodiments of the invention will be explained in more detail below with the aid of the drawing, in which:

Fig. 1 schematically shows a plan view of a data carrier according to the invention

Fig.	2	shows a	cross	section	through a	data	carrier
		according	to the invention,
Fig.	3	shows a	cross	section	through a	data	carrier
		according	to	the invention according	to a
		variant,
Fig.	4	shows a	cross	section	through a	data	carrier

according to another variant.

DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS

Figure 1 shows a data carrier 1, which according to Figure 2 comprises an opaque core sheet 7, a lower transparent cover sheet 8 and an upper transparent cover sheet 6. A métal layer is applied onto an upper side 14 of the core sheet 7, for example vapor deposited or applied by hot stamping. In what follows, a métal layer also refers to a metallized layer or a metallic layer. Such layers are known per se. They are relatively thin and hâve for example a thickness of 4 micrometers, preferably less than 1 micrometer. The métal sheet may also be formed as a hologram. The cover sheet 6, the core sheet 7 and the lower cover sheet 8 are bonded in a manner known per se by lamination. The métal layer 5 then correspondingly lies between the core sheet 7 and the cover sheet 6. Using a laser apparatus, the métal layer is removed in such a way that, for example, the ablated second image 3 and the ablated second text 4 are formed in Fig. 1. They are preferably formed by a recess in the métal layer 5. The opaque core sheet is visible through these recesses. Before the application of the métal layer, the opaque core sheet may be printed in the région of the métal layer or below the latter. The second image 3 and the second text 4 can then

- 6 correspondingly be seen in a color hue. Then, the second text 4 therefore appears blue or red, for example.

The data carrier according to Fig. 3 has a core sheet 7' , which comprises a transparent sheet 9 on which the métal Iayer 5' is applied, for example vapor deposited. The ablated régions are in this case visible from both sides, that is to say in Fig. 3 from above through the cover sheet 6 and from below through the cover sheet 8.

Fig. 4 shows a data carrier 1' which comprises a core sheet 12 that has a transparent sheet 13, which comprises a first métal Iayer 10 and a second métal Iayer 11. These métal layers 10 and 11 may likewise be vapor deposited or applied by hot stamping. These two métal sheets 10 and 11 are at a distance from one another of, for example, at least 50 micrometers or preferably 100 or more micrometers. During the ablation using the laser, as indicated, the data carrier 1' is placed obliquely at a predetermined angle A. The ablation takes place in the two métal layers 10 and 11. If, owing to the laser intensity, it is not possible to ablate the two métal layers 10 and 11 from the same side of the card, two matching laser processes may also be envisioned on the rear side and the front side of the data carrier 1' . In this case, the closer-lying métal Iayer 10 or 11 is respectively processed. By identical placement of the data carrier 1' before the laser processing, the lasered image is visible in transparent view only at the corresponding viewing angle. It is also conceivable to laser two different images with different angles from one another, and thus obtain a tilt effect between the two images, or the two métal layers 10 and 11, during observation at different angles. The core Iayer 12 may, as can be seen, be fastened and in particular laminated between two layers, or cover sheets.

- 7 LIST OF REFERENCES data carrier métal sheet

3 ablated second image ablated second text métal layer cover sheet opaque core sheet

8 transparent cover sheet transparent sheet first métal sheet second métal sheet core sheet

13 transparent sheet upper side w''

Claims (14)

1. A method for producing a multilayer data carrier, which has a first layer of plastic that comprises an upper side on which an opaque layer partially covering this upper side is arranged, and having a second layer of plastic which is arranged on the first layer and is transparent at least in a subregion of the opaque layer, characterized in that the opaque layer is partially removed using a laser until the opaque layer has at least one recess, or the opaque layer is produced from a material which is modified during the exposure in such a way that it becomes transparent or at least translucent in the exposed région.

2. The method as claimed in claim 1, characterized in that the opaque layer is laminated between the first and second plastic layers and/or in that the opaque layer is arranged in a window of the otherwise at least regionally opaque layer (1) and/or in that the opaque layer is a métal layer.

3. The method as claimed in one of claims 1 to 2, characterized in that the data carrier is produced with at least two métal sheets arranged parallel above one another, and these two métal sheets are provided with recesses.

4. The method as claimed in claim 3, characterized in that the two métal layers are exposed vertically with respect to their plane or at an inclination with respect to their planes, so that the recesses extend vertically or at an inclination with respect to said planes and/or in that the at least two métal sheets are arranged at a distance from one another. va/

5. The method as claimed in one of claims 3 to 4, characterized in that the at least two métal sheets are arranged in a window of an opaque core sheet.

6. The method as claimed in claim 5, characterized in that the core sheet is laminated between two transparent sheets.

7. The method as claimed in claim 1-2, characterized in that the opaque layer is a plastic layer, which has an additive that modifies the plastic layer during the exposure to the laser in such a way that the opaque layer becomes transparent in the exposed région.

8. The method as claimed in claim 7, characterized in that the opaque plastic layer is at least 20 micrometers thick, preferably at least 50 micrometers thick and/or in that the laser vertically inclination with recesses extend opaque plastic layer is its plane plane, so that inclination with with respect respect to vertically or to its at an exposed to or at the an the respect to said plane.

9. A data carrier produced according to one of claims 1 to 8.

10. The data carrier as claimed in claim 9, characterized in that it is an identity card, a page of a passport, a crédit card or the like.

11. The data carrier as claimed in claim 9 or 10, characterized in that the opaque layer is a métal layer which is vapor deposited onto a sheet, applied by hot stamping or laminated together with a carrier layer.

12. The data carrier as claimed in one of claims 9 to 11, characterized in that the métal layer is thinner than 4 micrometers, preferably thinner than 1 micrometer and/or in that in the case of two métal layers, they are at a distance from one another of at least 50 5 micrometers, preferably at least 100 micrometers and/or in that the opaque layer is produced from a plastic, and wherein the latter is transparent or translucent in an exposed région and/or in that the opaque layer is preferably produced 10 from a pigmented or semicrystalline plastic.

13. The data carrier as claimed in one of daims 9 to

12, characterized in that the ablated régions are visible from both sides of the data carrier.

14. The data carrier as claimed in claim 11, characterized in that owing to the reflection behavior of the métal layer, the image when viewed can be seen as positive or négative depending on the viewing angle. '