GB2283701A

GB2283701A - An applied film to prevent copying of a document.

Info

Publication number: GB2283701A
Application number: GB9412158A
Authority: GB
Inventors: Helmut Steininger; Peter Heilmann; Gerhard Plasonig
Original assignee: BASF Magnetics GmbH
Current assignee: Emtec Magnetics GmbH
Priority date: 1993-06-30
Filing date: 1994-06-17
Publication date: 1995-05-17
Anticipated expiration: 2014-06-17
Also published as: DE4321685A1; FR2708756B3; GB9412158D0; DE9410017U1; GB2283701B; JPH07219186A; FR2708756A3

Description

2283701 ANTICOPYING FILM This invention relates to an anticopying f ilm

for masking documents, of the kind comprising a film of transparent material having uniformly recurring opaque or reflective sections in the thickness of the film material or parts thereof, which sections, due to their corresponding geometrical arrangement, make the film appear opaque for a defined viewing angle range onto the film and make the film appear transparent in other viewing angle ranges.

An anticopying film of the type referred to above is described in German Patent Application P 42 26 906. The film, which is intended to render documents uncopyable by a photocopying machine, substantially comprises a transparent plastics f ilm with opaque regions in a multiplicity of different arrangements incorporated in or on the surfaces of said film, by which regions the film appears opaque in the of illumination of a copier and appears transparent from a different viewing angle range. In this case, the anticopying film may be fastened on the document to be masked by means of commercially available adhesive and bonding agents.

direction It is an object of the present invention to make an anticopying film suitable for use in only partially masking a document.

We have found that this object is achieved by an anticopying film of the kind referred to in which, according to the invention, the format of the anticopying film is smaller than the format of the document to be masked.

Embodiments of the invention will now be described, by way of example only, with particular reference to the accompanying drawings, in which Figure 1 is a schematic cross-sectional view of an anticopying f ilm with a base adhered to a document by an adhesive coating, Figure 2 is a schematic cross-sectional view of an anticopying film with a base and an adhesive coating as in Figure 1 and with a removable cover film, and Figure 3 is a schematic cross-sectional view of an anticopying film without a base but with an adhesive coating and a removable cover film.

The anticopying film is represented in cross section in the drawings and comprises a film 3 of transparent material which is of the size of a document 2 to be masked or of a part thereof and has uniformly recurring opaque or reflective sections 5 in the thickness of the film material or parts thereof. These sections may also be printed on. By a mutually offset arrangement of the sections, in a way similar to an adjustable venetian blind, the film appears opaque when viewed from above, corresponding to the copying direction 6, and transparent when viewed from a slightly oblique direction 7. Various embodiments of this structure of the film are shown and explained in the German patent application referred to at the beginning of this specification.

For versatile and easily manageable use of the anticopying film, it is expedient to produce it in customary formats and forms which are smaller than the format of the document to be masked, in order in this way to be able also to make limited passages of text uncopyable, such as paragraphs, lines, addresses etc. In this case, it is advantageous to present the anticopying film sheets in a storage or dispensing box or to provide them together in tear-off blocks.

To obtain permanent protection of the passages of text etc. to be covered, the anticopying film 3 must be bonded to the document 2 in such a way that, when the smallformat anticopying film is detached, the document 2 is at J Z 1 i- least partially destroyed. It is therefore expedient to provide the base film 1 of the anticopying film 3 or the latter itself directly with an adhesive coating 4. The adhesive 4 is to adhere permanently on the document material 2, in most cases probably paper of cellulose or cellulose plus polymer material, and not be detachable. The same of course also applies to the adhesion and undetachability of the adhesive 4 from the base film 1 or the coating material of the anticopying film 3 itself.

Suitable adhesives 4 are solvent adhesives or dispersion adhesives, with particular advantage those based on water. Such adhesives can be applied, for example laminated on,, in a wet or moist state, allowed to dry without losing their adhesive effect and are then covered, if necessary, by a release film 8 or a release sheet, for example silicone paper (see Figures 2 and 3).

The adhesive 4 may be an acrylic adhesive, for example phenyl acrylate. A polychloroprene may also be used. The adhesive may also be based on styrenebutadiene.

Heat-sealable adhesives can also be used of course, for example a laminated-on polyethylene film, which can be applied with the application of heat and which cannot subsequently be detached.

An acrylate adhesive is preferably crystal clear, that is to say transparent, so that the only partially transparent film 3 definitely has to remain on the document 2.

The anticopying film 3 can be cut to size to any desired small formats and forms, for instance from a DIN A4 format or a corresponding paper format in the USA. The forms are primarily no doubt rectangular or square, but may also be trapezoidal or rhomboid or triangular or round.

The invention can of course also be used to advantage for formats smaller than DIN A4, for example in book - 4 formats, and far larger formats, for example for newspaper formats up to DIN AO or larger.

J The invention relates to an anticopying f ilm for masking documents which appears opaque when viewed substantially vertically from above and transparent when viewed from an oblique direction to provide protection against copying, the format of the anticopying film being smaller than the format of the document to be masked and the anticopying film adhering permanently to the document by 10 means of an adhesive.

-:c

Claims

1. An anticopying film for masking documents of a given format, comprising a film of transparent material having uniformly recurring opaque or reflective sections in the thickness of the film material or parts thereof, which sections, due to their corresponding geometrical arrangement, make the film appear opaque for a defined viewing angle range onto the film and make the film appear transparent in other viewing angle ranges, wherein the format of the anticopying film is smaller than the provided format of the document to be masked.

2. An anticopying film according to claim 1, wherein a multiplicity of anticopying f ilms of the customary formats and forms are provided together in tear-off blocks.

is

3. An anticopying film according to claim 1 or 2, provided on one side with an adhesive which adheres permanently on the document material and is not detachable.

4. An anticopying film according to claim 3, wherein the adhesive is a solvent adhesive or dispersion 20 adhesive.

5. An anticopying film according to claim 4, wherein the adhesive is an acrylate adhesive, for example phenyl acrylate.

6. An anticopying film according to claim 4, 25 wherein the adhesive is a polychloroprene.

7. An anticopying film according to claim 4, wherein the adhesive is based on styrene-butadiene.

8. An anticopying film according to any of claims 3 to 7, in which the adhesive is covered by a release film 30 or a release sheet, for example siliconized paper.

9. An anticopying f ilm according to claim 3, in which the adhesive is formed by a heat-sealable film, for example a polyethylene film.

j

10. An anticopying film for masking documents of a given format, constructed and arranged substantially as herein described with reference to, and as illustrated in, Figure 1, 2 or 3 of the accompany drawings.

L

11. An anticopying film according to any of the preceding claims, in combination with a document to be 10 masked which is of larger format than that of the anticopying film.

12. A combination according to claim 11, in which the anticopying film is permanently adhered to the document.