WO2023200369A1 - Multi-layered structure for protecting identification documents - Google Patents

Abstract

The invention relates to an information carrier, primarily an identification document provided with a structure having optically variable properties and a laminating non-film material for protecting against tampering and counterfeit. Proposed is a multi-layered structure for protecting identification documents which includes a removable base film having the following successively applied to one side thereof: a release layer; a relief-forming layer with a diffractive security element; a demetallized layer of aluminium with localized non-transparent regions, which is coated with a polymer layer; a reflecting layer of zinc sulphide; a printed ink layer; and an adhesive layer for attaching the structure to a document to be protected. Also proposed is an identification document in the form of a passport book containing the claimed multi-layered structure. The technical result is that of permitting more reliable verification of the authenticity of a document by increasing the brightness of a hidden reconstructable image, while also increasing the speed with which control experts can process documents.

Description

MULTILAYER STRUCTURE TO PROTECT IDENTIFICATION DOCUMENTS

The invention relates to an information carrier, mainly an identification document, equipped with a structure with optically variable properties and a non-film laminating material for protection against unauthorized opening and counterfeiting.

To protect valuable documents, such as a passport, and other printed products, optically variable means applied to their surface, for example, a diffraction grating, a hologram or other optical microstructures, are widely used.

The known solution is RU 2461882, 03/10/2011, the technical result of which is to increase the information security of a document by introducing individual features of the document into the hologram. This solution seems technically difficult to implement and, as shown below, each specific document has its own distortions of the optical image, which do not allow achieving the required level of accuracy in modulating the system signal without the presence of a reference signal.

The solution RU 2361252, 04/27/2008 is known, describing a storage medium with an inner layer and at least one adjacent layer laminated onto the inner layer, and a method for its manufacture. The specified inner layer is made of a holographic means of storing information in the form of a volumetric hologram. The surface of the layer adjacent to the inner layer facing the inner layer has a roughness before lamination on the inner layer, which causes a shift in the wavelength of the image reconstructed by the volumetric hologram with a fixed distortion. Technical result -

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SUBSTITUTE SHEET (RULE 26) increasing protection against falsification by creating a sophisticated optical system with double diffraction of the reflected wave.

According to the authors, this technical solution is the closest analogue of the claimed invention. The disadvantage of the known technical solution is the serious problem of combining flat and volumetric holograms to obtain a low-noise reconstructed wave reflected from the carrier, which is unattainable in mass production conditions.

It has been empirically established that when applying a diffraction protective relief fixed in amplitude (relief phase “flat hologram”), due to the amorphous surface of the paper, consisting of fibers of different lengths and orientations, both phase and amplitude, and sometimes frequency distortions of the restored image are possible. image.

The main idea of the claimed invention is the creation of an optical system, the average error of the reconstructed image signal at all points of which would allow for minimal influence or complete elimination of noise from the amorphous surface of paper or other rough substrate.

The problem solved by the invention is to increase the reliability of identifying the authenticity of a document by increasing the brightness of the imaginary restored image, as well as increasing the speed of document processing by control specialists.

This is achieved by proposing a multilayer structure for the protection of identification documents, including a removable base film, on one side of which the following are successively applied: a separating layer, a relief-receiving layer with a diffraction protective element, a demetallized layer of aluminum or copper or nickel with local opaque zones, a reflective layer of zinc sulfide or indium tin oxide, a printing ink layer and an adhesive layer to secure the structure to the document to be protected.

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SUBSTITUTE SHEET (RULE 26) In particular cases, the demetallized layer can be coated with a layer of polymer.

In particular cases, the printing ink layer is iridescent paint, and/or luminescent paint, and/or color-changing paint, and/or sublimation paint in any combination, applied both with a die and in the form of local elements.

The base film can be designed to be removed upon partial wear.

The printing ink layer may include images that respond when excited by ultraviolet light, infrared light, an external magnetic field, or thermal radiation.

An identification document in the form of a passport book is also proposed, containing the claimed multilayer structure, where the multilayer structure is applied to at least one of the pages of the identification document.

In special cases, a multilayer structure can be applied to pages on both sides of the sheet of an identification document.

The multi-layer structure can be applied to the flyleaf of the identification document

It is known that the average height of paper relief peaks can reach 15 microns, which is no less than 30-60 times greater than the relief usually used for embossing protective diffraction elements.

In our case, the average relief value was in the range from 0.2 to 0.3 μm. The noise of the optical reflected signal from the substrate arises both due to the paper’s own roughness and due to the processes of deformation and relaxation stretching/shrinkage of both the base film and the adhesive layer, which becomes especially noticeable with sudden changes in external factors, such as humidity and temperature.

To reduce the influence of these factors, the structure of the lamination material has been developed, one of the main differences of which is

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SUBSTITUTE SHEET (RULE 26) total thickness different from both classic hot-stamping foil with diffraction protective elements and traditional lamination materials made using base films.

One of the advantages of the proposed solution is the preservation of the impossibility of tearing off the lamination layer from the substrate without destruction, similar to the property of classical foil to self-destruct upon tearing.

Moreover, unlike laminates having a carrier film with a thickness of 21 to 200 microns and printing foils having an average thickness of 1.5 microns, this solution retains the advantages of foil as a destructible element of protection in the event of an attempt to transfer and at the same time retains the property of laminates that provide increasing rigidity and resistance to external influences due to the use of increased thicknesses of varnish and adhesive layers.

To achieve the technical result, two additional functional layers were used. The first is an adhesive layer with a thickness of 0.2 to 12 microns, depending on the type of substrate (paper, plastic, synthetic paper), which is also a damping layer during the pressing process and ensures complete filling of the depressions on the surface of the base to eliminate distortions due to additional boundaries phase separation that occurs in cases of conventional gluing. The second is a layer bearing a diffraction structure, having a thickness of 0.1 to 10 microns, and is a power layer that increases the transverse rigidity of the finished product with an applied laminate up to three times, compared to a material using foil.

The essence of the claimed invention is illustrated in the examples below.

As examples, we give some average layer thicknesses and some parameters of diffraction gratings for use when laminating a page with personal data in a passport book made of paper or polycarbonate.

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SUBSTITUTE SHEET (RULE 26) Example 1

The page with personal data of the passport book is made of paper.

Laminate is a multilayer polymer material combined with release paper, consisting of varnish layers, embossing with a separating layer with a holographic image, on the inside of which protective elements and glue are applied:

1. Paper, siliconized one-sided - 70 microns;

2. Heat-activated adhesive with residual stickiness - 1 micron;

3. Base film, polyester, thickness - 19 microns;

4. Separating layer - 3 microns;

5. Relief-receiving layer - 1.5 microns;

6. Demetallized layer of aluminum - 2000 A;

7. Reflective layer of zinc sulfide - 1000 A;

8. Protective primer layer - 2 microns;

9. Luminescent paints UV excitation - 1 micron;

10. Adhesive layer - thermally activated glue for lamination on paper - 0.8 microns.

The holographic image is made with relief in the range of 0.3 - 0.6 microns and contains:

- High resolution lines;

- Diffraction bas-relief;

- Lens with the effect of changing characters;

- Nano and microtexts.

As additional protective elements, images and inscriptions printed with sublimation and photochromic paints are applied on the side of the varnish layers under the glue. The lamination page also contains aluminum metallization with stochastic raster demetallization.

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SUBSTITUTE SHEET (RULE 26) The laminate is connected to the release paper (rolled) along the upper long edge of the sheet with a rolling width of (10±0.5) mm and along the lower edge with a rolling width of (2±0.5) mm.

The lamination page and release paper are perforated from the top along the long side at a distance of (8±0.5) mm from the edge of the laminate. Before hot rolling to the document page, the release paper is first removed, and after rolling, the base film of the hot stamping foil is removed using a special strap.

The adhesive coating acquires adhesive properties under the influence of temperature (130±10)°C and pressure from the laminator rollers.

Example 2

The page with personal data of the passport book is made of polycarbonate

Laminate is a multilayer polymer material combined with release paper, consisting of varnish layers, embossing with a separating layer with a holographic image, on the inside of which protective elements and glue are applied:

1. Paper, siliconized one-sided - 70 microns;

2. Heat-activated adhesive with residual stickiness - 1 micron;

3. Base film, polyester, thickness - 19 microns;

4. Separating layer - 1.5 microns;

5. Relief-receiving layer - 3.5 microns;

6. Demetallized copper layer - 2000 A;

7. ITO reflective layer - 1000 A;

8. Protective primer layer - 2 microns;

9. Luminescent paints UV excitation - 1 micron;

10. Adhesive layer - thermally activated adhesive for lamination on polycarbonate - 1.2 microns.

The holographic image is made in relief in the range (0.6 - 0.8) microns and contains:

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SUBSTITUTE SHEET (RULE 26) - high resolution lines;

- diffraction bas-relief;

- a lens with the effect of changing characters;

- nano and microtexts;

- hidden visualized marks.

As additional protective elements, images and inscriptions printed with sublimation and photochromic paints are applied on the side of the varnish layers under the glue. The lamination page also contains ITO metallization with demetallization to enhance adhesion.

The laminate is connected to the release paper (rolled) along the upper long edge of the sheet with a rolling width of (10±0.5) mm and along the lower edge with a rolling width of (2±0.5) mm.

The lamination page and release paper are perforated from the top along the long side at a distance of (8±0.5) mm from the edge of the laminate. Before hot rolling to the document page, the release paper is first removed, and after rolling, the base film of the hot stamping foil is removed using a special strap.

The adhesive coating acquires adhesive properties under the influence of temperature (150±10) °C and pressure of a semi-rotary metal press.

Example 3

The page with personal data of the passport book, made of synthetic or semi-synthetic paper, is laminated on both sides.

The front side laminate is a multilayer polymer material combined with release paper, consisting of varnish layers, embossing with a separating layer with a holographic image, on the inside of which protective elements and glue are applied:

1. Paper, siliconized one-sided - 70 microns;

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SUBSTITUTE SHEET (RULE 26) 2. Heat-activated adhesive with residual stickiness - 1 micron;

3. Film - base, polyester, thickness - 19 microns;

4. Separating layer - 1.5 microns;

5. Relief-receiving layer - 3.5 microns;

6. Demetallized copper layer - 2000 A;

7. ITO reflective layer - 1000 A;

8. Protective layer - primer - 2 microns;

9. Luminescent paints UV excitation - 1 micron;

10. Adhesive layer - thermally activated adhesive for lamination on polycarbonate - 1.2 microns.

The holographic image is made in relief in the range (0.6 - 0.8) microns and contains:

- high resolution lines;

- diffraction bas-relief;

- a lens with the effect of changing characters;

- nano and microtexts;

- hidden visualized marks.

The laminate for the reverse side is a multilayer polymer material consisting of varnish layers, embossing with a relief-receiving layer with a holographic image, on the inside of which protective elements and glue are applied:

1. Base film, polyester, thickness - 50 microns;

2. Relief-receiving layer - 2 microns;

3. Reflective layer of zinc sulfide - 1000 A;

4. Primer layer - 1.5 microns;

5. Luminescent paints UV excitation - 0.8 microns;

6. Lamination adhesive layer - 75 microns.

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SUBSTITUTE SHEET (RULE 26) Both lamination covers are sewn into the passport book on both sides of the page with personal data. For the front laminate, before lamination, actions similar to examples 1 and 2 are performed. The back laminate does not require special preparation procedures.

Example 4

Lamination of the page with personal data of the passport book if it is located on the flyleaf.

Laminate is a multilayer polymer material combined with release paper, consisting of varnish layers, embossing with a separating layer with a holographic image, on the inside of which protective elements and glue are applied:

1. Siliconized paper, one-sided - 70 microns;

2. Heat-activated adhesive with residual stickiness - 1 micron;

3. Base film, polyester, thickness - 19 microns;

4. Separating layer - 3 microns;

5. Relief-receiving layer - 1.5 microns;

6. Demetallized aluminum layer - 2000 A;

7. Reflective layer of zinc sulfide - 1000 A;

8. Protective primer layer - 2 microns;

9. Luminescent paints UV excitation - 1 micron;

10. Adhesive layer - thermally activated glue for lamination on paper - 0.8 microns.

The holographic image is made in relief in the range (0.3 - 06) microns and contains:

- high resolution lines;

- diffraction bas-relief;

- a lens with the effect of changing characters;

- nano and microtexts.

As additional protective elements on the side of the varnish layers under the glue, printed sublimation and photochromic 9

SUBSTITUTE SHEET (RULE 26) painted images and inscriptions. The lamination page also contains aluminum metallization with stochastic raster demetallization.

It is possible to produce a passport book cover with a glued microchip due to the low rolling temperature - (130 ± 10) °C and pressure in the chip area.

The proposed solution makes it possible to reduce the signal-to-noise ratio in the system, all other things being equal, by at least two times. The parameters of diffraction gratings and thicknesses of varnish layers were selected, leading to minimal signal-to-noise values in the system when restoring a virtual image. The averaged parameters of the combination of refraction and reflection angles in the complex were selected, having the lowest average signal-to-noise ratio under the same conditions.

The system includes an adhesive layer, which, in addition to the function of gluing, acts as a damper due to its increased thickness and selected internal reflection coefficient.

In this case, the optical properties of both the adhesive and the varnish layers are selected so that the refractive index is not a multiple of the half-wavelength of the optical range, generally accepted for calculations as (555 nm).

SUBSTITUTE SHEET (RULE 26)

Claims

CLAIM 1. Multilayer structure for protecting identification documents, including a removable base film, on one side of which the following are successively applied: a separating layer, a relief-receiving layer with a diffraction protective element, a demetallized layer of aluminum or copper or nickel with local opaque zones, a reflective layer of sulfide zinc or indium-tin oxide, a printing ink layer and an adhesive layer for fixing the structure on the protected document, wherein the thickness of the adhesive layer is from 0.2 to 12 microns, the thickness of the relief-receiving layer with a diffraction element is from 0.1 to 10 microns. 2. Multilayer structure according to claim 1, characterized in that the printing ink layer is iridescent paint, and/or luminescent paint, and/or color-changing paint, and/or sublimation paint in any combination, applied either as a die or in the form local elements. 3. Multilayer structure according to claim 1, characterized in that the base film is designed to be removed when partially worn. 4. Multilayer structure according to claim 1, characterized in that the printing ink layer includes images that respond when excited by ultraviolet light, infrared light, an external magnetic field or thermal radiation. 5. An identification document in the form of a passport book, containing a multilayer structure according to any of paragraphs 1-4, where the multilayer structure is applied to at least one of the pages of the identification document. 6. Identification document according to claim 5, characterized in that the multilayer structure is applied to pages on both sides of the sheet of the identification document. eleven SUBSTITUTE SHEET (RULE 26) 7. Identification document according to claim 5, characterized in that the multilayer structure is applied to the flyleaf of the identification document. 12 SUBSTITUTE SHEET (RULE 26)