HK1008320A1 - Folder for a document - Google Patents

Abstract

One of the film sections (1) consists of a multilayered film arrangement. The outermost layer (10) has a softening temp. which is at least 20 [deg]C above the lamination temp. and carries a hologram on the inside. The innermost layer of the film sections consists of a melt adhesive film (15) with a softening temp. which is less than or equal to the lamination temp.

Description

The invention relates to a foil bag for the reception and subsequent lamination of a document, e.g. an identity document, between two sheets of film of a transparent thermoplastic plastic, connected by a fold, forming the bag.

The paper bags are designed to protect the laminated or sealed document not only from external influences but also from manipulation of the usually personal data and other authentication features (such as photo and/or signature) on the document. The document is usually made of paper and is a so-called paper inlay, which is a few millimetres smaller than the paper bag. This in turn consists of at least one layer of film, e.g. PE, PP, PS, PVC, PET, etc., with a softening temperature generally between 60 and 80°C. The paper inlay, which is usually loose from the total film and inserted between the two sheets, is then passed through a so-called laminator, the paper sheets of which are heated to 130°C. The remaining sheets of paper are then softened against the walls and the other sheets of paper against the walls.

Whereas it is relatively difficult to manipulate a document laminated in this way, a complete forgery is all the easier because a suitable paper inlay can be made to resemble a corresponding original document by means of a colour copier and/or an electronic image processing system and laminated in a commercial paper bag in the manner described.

In EP 0 440 045 A2 we describe a data carrier, e.g. a security, with a hologram applied to its surface and an additional printed image.

The purpose of the invention is to create a foil bag which, provided it is distributed in a controlled manner, makes complete falsification of laminated or sealed documents impossible.

This problem is solved by the invention, which consists of at least one of the sheets of film consisting of a multilayer film, the outermost layer of which has a softening temperature at least 20°C above the in-lamination temperature and which bears a prehologram on the inside, and the innermost layer of the sheet consists of a melt adhesive film with a softening temperature less than or equal to the in-lamination temperature.

If the above multilayer film has only two layers, which is usually sufficient, the prehologram is on the inside of the outer layer and the above melt adhesive film forms the inner layer.

The proposed solution has the advantage that the prehologram, which is known as a security feature, cannot be reproduced with reasonable effort or be simulated by means of colour copiers and/or photographic techniques.

Preholograms, i.e. high-resolution deflection grids (e.g. 1200 lines/mm) and the technical methods for their production are known.

It is advantageous from a manufacturing point of view if the melt adhesive film is covered by a cross-linked, non-supporting acrylic adhesive against the prehologram layer (claim 2).

Preferably, the pre-hologram occupies at least the majority of the surface of the sheet (claim 3). However, it is not recommended to apply the pre-hologram to a small part of the sheet, as this would mean that the pre-hologram could be cut out and incorporated into a counterfeit using a commercial paper bag.

As an additional security feature, the prehologram may include a (machine-readable) marking, e.g. in the form of a barcode (claim 4).

An additional aesthetic or advertising effect is possible by additionally conventional printing the outermost layer of the multilayer film on the inside (claim 5).

A simple printing of a transparent film with a relief surface containing the holographic information is not sufficient to reconstruct the holographic information, i.e. the visual recognition of the subject.

One option is to coat the outermost layer of the sheet of film bearing the prehologram with a transparent material with a refractive index of at least 20%, preferably at least 30%, greater than that of the outermost layer of the film material (claim 6). Most materials that qualify as film materials have an index of refraction between 1.4 and 1.6.

The layer thickness of the transparent coating depends on the degree of transparency of the material concerned and can be between 10 and 100 nm, preferably between 15 and 25 nm (claim 7).

The coating material is suitable for a number of metal oxides, which can be evaporated or sprayed. Some metal sulfides such as ZnS, CdS and Sb2S3 are also suitable.

Another way of ensuring good visual recognition of the image motif contained in the prehologram is to coat the surface of the outermost layer of the foil sheet bearing the prehologram with a coating of a reflective material in a cover which does not yet affect the legibility of the document in normal lighting conditions (claim 9).

To avoid a noticeable deterioration in the transparency of the sheet and thus the legibility of the document, the layer thickness of the reflective coating should be less than 20 nm (claim 10).

Alternatively or additionally, sufficient transparency can be achieved by having the layer thickness of the reflective coating exceed 20 nm in at least parts of the surface and by having at least part of the coating consist of a grid with a coverage of between 15 and 40% (claim 11). If the reflective coating is made of aluminium, for example, the desired grid can be produced by passing the first fully aluminium-vaporised carrier layer or film under a roller which carries the reflective grid as a surface and whose existing structures are protected with 20% sodium nitrate.

The reflective coating only needs to cover part of the surface of the outermost layer of the film sheet (claim 12). The covered surface need not necessarily be enclosed in itself, but the covered sub-surfaces, which may in turn have different degrees of coverage, can additionally generate a non-holographic image motif, even in semi-dramatic form, if necessary.

In particular, the reflective coating may also contain a visual and/or machine-readable marking (claim 13).

A section of a sheet of paper bag according to the invention with an inserted identity document is shown in the diagram. The sheet of paper bag consists of the upper sheet of sheet 1 and the lower sheet of sheet 2.

The upper film sheet 1 is essentially a two-layer film, whose outer layer 10 is in turn multilayered and includes a first layer 11 of e.g. 50 μm thick PET film. On the inside, PET film 11 has a coating 12 of acrylic lacquer with a thickness of e.g. 5 μm. In this acrylic layer 12 is embedded an unrecognizable in the drawing refractive grating which contains the hologram motif. The relief embossed in layer 12 can reach up to or even into the reflective surface of layer 11 on the inside.

Against this layer 10 a blister-free laminated melt adhesive film 15 is placed over a cross-linked, supportless layer of acrylic adhesive 14 also known as hot-adhesive film or melt film, the thickness of the acrylic adhesive layer 14 being, for example, 20 μm and that of the melt adhesive film 15 being, for example, 100 μm.

The purpose of the acrylate adhesive layer 14 is to laminate the melt adhesive film 15 against the outer layer 10 by machine. melt adhesive film 15 is necessary to laminate the upper sheet 1 against the paper inlay 3 and, in the edge area of the foil bag, also against the lower sheet 2 by means of a conventional roll laminator operating at temperatures of 120 to 140°C.

For outer layer 10, more specifically for the layer containing the prehologram, a plastic must be used with a softening temperature at least 20°C higher than the working temperature of the roll laminator, otherwise the prehologram would be destroyed during the lamination of the paper inlay 3.

The lower sheet 2 may, if desired, be similar in principle to the paper inlay 3, but have a mirror-like structure as the upper sheet 1.

The following table shows the results of the tests carried out in the manufacture of the products:

Claims (13)

1. A foil case for receiving a document (3), for example an identity document, and subsequent lamination therein, between two foil sheets (1, 2) of a transparent thermoplastic material which are joined by way of a fold and which form the case, in a laminator, characterised in that at least one of the foil sheets comprises a multi-layer foil whose outermost layer (10) has a softening temperature at least 20°C above the operating temperature of the laminator and which on the inside carries an embossing hologram, and that the innermost layer of the foil sheet (1) comprises a melt adhesive foil (15) with a softening temperature that is lower than or equal to the operating temperature of the laminator.
2. A foil case according to claim 1 characterised in that the melt adhesive foil (15) is laminated against the layer carrying the embossing hologram by way of a cross-linked, carrier-less acrylate adhesive (14).
3. A foil case according to claim 1 or claim 2 characterised in that the embossing hologram occupies at least the predominant part of the surface area of the foil sheet (1).
4. A foil case according to one of claims 1 to 3 characterised in that the embossing hologram includes a machine-readable identification.
5. A foil case according to one of claims 1 to 4 characterised in that the outermost layer (10) of the multi-layer foil is additionally conventionally printed upon at the inside.
6. A foil case according to one of claims 1 to 5 characterised in that the surface, which carries the embossing hologram, of the outermost layer (10) of the foil sheet (1) is provided with a coating (13) comprising a transparent material whose refractive index is at least 20% and preferably at least 30% greater than the refractive index of the foil material (11, 12) forming the outermost layer.
7. A foil case according to claim 6 characterised in that the layer thickness of the transparent coating (13) is between 10 and 100 nm, preferably between 15 and 25 nm.
8. A foil case according to claim 6 or claim 7 characterised in that the transparent coating comprises titanium dioxide.
9. A foil case according to one of claims 1 to 5 characterised in that the surface, carrying the embossing hologram, of the outermost layer (10) of the foil sheet (1) is provided with a coating (13) of a reflecting material in a cover which still does not impair readability of the document under normal lighting conditions.
10. A foil case according to claim 9 characterised in that the layer thickness of the reflecting coating (13) is less than 20 nm.
11. A foil case according to claim 9 or claim 10 characterised in that the layer thickness of the reflecting coating (13) is more than 20 nm and that the reflecting coating at least partially comprises a grid whose degree of covering is between 15 and 40%.
12. A foil case according to one of claims 1 to 11 characterised in that the reflecting coating (13) covers only a part of the surface area of the outermost layer of the foil sheet.
13. A foil case according to one of claims 9 to 12 characterised in that the reflecting coating (13) contains a visually and/or machine-readable identification.