NZ707967B2 - Method for producing a multilayer data carrier and data carrier produced by said method - Google Patents

Abstract

Method for producing a multilayer data carrier for example an identity card, passport, or driver’s license, which is protected against unauthorised modifications. The data carrier has a first layer (8) of plastic that comprises an upper side on which an opaque layer (5') partially covering this upper side is arranged. A second layer (6) of plastic is arranged on the first layer (8) and is transparent at least in a subregion of the opaque layer (5'). The opaque layer (5') is partially removed using a laser until the opaque layer (5') has at least one recess. The opaque layer is arranged within a window of an opaque core sheet (7'). r side is arranged. A second layer (6) of plastic is arranged on the first layer (8) and is transparent at least in a subregion of the opaque layer (5'). The opaque layer (5') is partially removed using a laser until the opaque layer (5') has at least one recess. The opaque layer is arranged within a window of an opaque core sheet (7').

Description

TITLE Method for Producing a Multilayer Data Carrier and Data Carrier ed by said Method TECHNICAL FIELD The ion relates to a method according to the preamble of claim 1.

In order to protect data carriers, for example identity cards, rts, driver's licenses, bank cards etc. having personalized data, security features are variously used. A very wide variety of ty 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 complete 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 special devices during the card production (lens structure) or special machines for introducing the second image. The present invention provides a way in which the personalization can be protected in a straightforward way t additional es.

PRIOR ART Any comment regarding prior art is not to be taken as an admission or acknowledgement that the prior art 40 forms part of the common general knowledge in the art.

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

EP 2 109 014 A1 discloses a so-called overlay of laserable polycarbonate with a holographic layer on one side. The holographic layer can be metallized and partially ablated using a laser. 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 ing a series of data carriers comprising holograms, in which the holograms are individualized by partial ction or modification of the diffraction structures.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a data r which is ted even better against unauthorized modifications. The data r is nevertheless intended to be produced economically. The object is ed according to claim Alternatively, it is an object of the invention, to at least provide the public with a useful choice.

According to one aspect of the invention there is provided a method for producing a multilayer data (Followed by page 2a) -2acarrier , which has a first layer of plastic that comprises an upper side which an opaque layer partially covering this upper side is ed, 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, n the opaque layer is produced from a material which is modified during exposure to a laser in such a way that it becomes transparent or at least translucent in the exposed region, n the material of the opaque layer is produced from a semicrystalline plastic or wherein the opaque layer is a plastic layer, which has an additive which is a plastic, in particular a pigment-like plastic or a pigmented plastic or a colorant plastic.

According to r aspect of the ion there is provided a data carrier produced according to the first aspect of the invention.

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 ably metallized thin layer is applied partially onto one of the layers. Thi (Followed by page 3) - 3 — metallized layer may for example be vapor deposited, applied by hot stamping or laminated together with a r layer (for example PET) n two layers of the data carrier. The metallized layer is advantageously thinner than 4 um, in the ideal case r than 1 um. If it is laminated together with a carrier layer, the carrier should be no thicker than 50 um, in the ideal case about 20 um or thinner. The metallized layer may contain holographic diffraction structures. The metallized layer consists, for example, of um, although other metals may be envisioned, for example titanium. The techniques for applying the metal layer onto a plastic sheet are known to the person skilled in the art. The thermoplastic sheet is advantageously thicker than 50 pm, in the ideal case 100 um or thicker.

The layer with the partially applied. metal 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 metal is covered with at least one further transparent layer. The layer onto which the metal 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 metal layer is then partially ablated, i.e. evaporated, using a laser. At the positions where the laser strikes the metal layer, the metal sheet evaporates and a recess is 3O formed in the metal. Text or matrix images can ore be written into the metal 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 g by means of blackening). It is, however, also possible to use a laser with a different wavelength. — 4 — When the metal layer is evaporated, the sheet below the metal layer is visible through the gap left in the metal sheet. ing on whether this sheet is transparent or opaque, the image formed in the metal layer is lly visible in transparent view (in the case of a transparent sheet) or direct view (in the case of an opaque sheet). Owing to the reflection behavior of the metal layer, the image can be seen in direct view as “positive" (dark) or “negative” (light) depending on the g angle.

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

According to a refinement of the invention, the metal 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 special additive is used instead of a netal layer, this ve 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 le to use a ystalline opaque plastic in which the macromolecules arranged in crystallites are ted 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.

Unless the t clearly requires otherwise, throughout the ption and claims the terms “comprise”, “comprising” and the like are to be construed in an inclusive sense, as opposed to an ive or exhaustive sense. That is, in the sense of “including, but not limited to”.

BRIEF DESCRIPTION OF THE DRAWINGS 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 r according to the invention Fig. 2 shows a cross section through a data carrier according to the invention, Fig. 3 shows a cross section h 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 MENTS 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 arent cover sheet 6. A metal 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 metal layer also refers to a metallized layer or a metallic layer. Such layers are known per se. They are relatively thin and have for example a thickness of 4 micrometers, preferably less than 1 micrometer. The (Followed by page 5a) - 5a - metal 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 metal layer 5 then correspondingly lies between the core sheet 7 and the cover sheet 6. Using a laser apparatus, the metal layer is removed in such a way that, for example, the d second image 3 and the (Followed by page 6) WO 97463 — 6 — ablated second text 4 are formed in Fig. 1. They are ably formed by a recess in the metal layer 5. The opaque core sheet is visible through these recesses.

Before the application of the metal layer, the opaque core sheet may be printed in the region of the metal layer or below the latter. The second image 3 and the second. text 4 can then 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 metal layer 5’ is applied, for example vapor deposited.

The ablated s are in this case visible from both sides, that is to say in Fig. 3 from above h 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 metal layer 10 and. a second Inetal layer ll. These metal layers 10 and ll may likewise be vapor ted or applied by hot stamping. These two metal sheets 10 and ll 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 metal layers 10 and ll.

If, owing to the laser intensity, it is not possible to 3O ablate the two metal layers 10 and ll 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 r 1’. In this case, the closer—lying metal layer 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 — 7 — images with different angles from one another, and thus obtain a tilt effect between the two images, or the two metal layers 10 and 11, during observation at different angles. The core layer 12 may, as can be seen, be fastened and in particular laminated n two layers, or cover sheets.

W0 2012/097463 - 8 — LIST OF REFERENCES data r metal sheet ablated second image ablated second text metal layer cover sheet CO\]O\U1:-I>0Jl\)|-‘ opaque core sheet transparent cover sheet w transparent sheet PAPA o first metal sheet F4 second metal sheet H N core sheet F4 o) transparent sheet H a upper side PATENT

Claims (9)

1. A method for producing a multilayer data carrier, which has a first layer of plastic that comprises an 5 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, wherein the opaque layer is produced from a 10 material which is modified during re to a laser in such a way that it becomes arent or at least translucent in the exposed region, wherein the material of the opaque layer is produced from a semicrystalline plastic or 15 wherein the opaque layer is a plastic layer, which has an additive which is a plastic, in particular a pigment-like plastic or a pigmented c or a colorant plastic. 20

2. The method as claimed in claim 1, wherein the opaque layer is ted between the first and second plastic layers.

3. The method as claimed in any one of claims 1 or 2, 25 wherein the multilayer data carrier ses a core layer between the first layer and the second layer which core layer is opaque and has a window, wherein in said window said opaque layer which is treated by said laser is arranged.

4. The method as d in claim 1, wherein the opaque plastic layer is at least 20 micrometers thick, ably at least 50 micrometers thick. 35

5. The method as claimed in any one of the preceding claims, wherein the opaque plastic layer is exposed to the laser perpendicular with respect to its plane or at an inclination with respect to its plane, so that the recesses extend ally or at an inclination with respect to said plane.

6. A data carrier produced according to any one of 5 claims 1 to 5.

7. The data carrier as claimed in claim 6, wherein it is an identity card, a page of a passport, or a credit card.

8. The data carrier as claimed in claim 6 or 7, wherein the opaque layer is ed from a plastic, and in that the layer is transparent or translucent in an exposed region.

9. The data carrier as claimed in any one of claims 6 or 8, wherein the exposed region is visible from both sides of the data carrier.