KR960012523B1 - Security paper for bank notes and the like - Google Patents

Abstract

No summary.

Description

Safe paper such as bank notes

The accompanying drawings show various embodiments of strips (or yarns) used in the present invention.

The present invention relates to safety paper such as banknotes and a method for manufacturing such paper.

In the present specification, the term "safety paper" means a paper of a special structure that cannot be forged by counterfeiters, and "safety paper" means banknotes and other security documents made from such paper.

It is well known for banknotes to use security strips or seals made of transparent films with continuous reflective metal layers, with vacuum deposited aluminum being the most common metal layer. Banknotes made from such papers have been accepted in many countries for many years. The main feature of such seals is that if they are embedded in safety paper and the paper is printed with safety papers, including banknotes, the seals cannot be easily identified in reflected light, but if the documents are projected in transmitted light, the security seals will produce dark It is immediately apparent. Such widely used security seals are simple in concept, but such devices are extremely effective because they cannot accurately mimic the optical variability provided, for example by printing lines on paper. The continued widespread use of these security features after initial introduction is strong evidence of their effectiveness.

It is known that metallized films can be made such that no metal is present at the controlled and clearly defined sites. The partially metallized film can be produced in various ways. One method is to selectively demetalize some regions using corrosion and etching techniques as described in US Pat. No. 4652015. Other techniques for achieving a similar effect are known, such as vacuum deposition of aluminum through a mask or selective removal of aluminum from a composite strip of plastic support and aluminum using an excimer laser. have.

It is important to provide better safety papers to improve public awareness / recognition of security offices for public authentication purposes. This can be accomplished by incorporating a pattern into the security chamber that is easily recognizable by the public while retaining the widely recognized optically variable effects provided by the continuously metallized strips. Many of the three currencies have microprinting chambers containing finely printed characters, but these characters are generally too small to be identified by naked eyes in printed banknotes. If the printed characters are larger, they are so obvious when viewed in reflected light that they are easily forged by counterfeiters. The present invention uses patterns or letters that are large enough to be easily recognized by the naked eye and formed of partially metallized strips so that the strong optical variable effects of the continuously metallized strips are essentially maintained.

According to the present invention, there is provided a security device in which a security device having a width of at least 5 mm or less positioned at least partially between two sides of a sheet of paper is provided as a safety feature of the public, comprising both sides providing printing to augment a document formed from such sheet of paper. Provided with paper, the device comprises a flexible, impermeable substrate having a metal layer on one or both sides, wherein one side of the device has a continuous metal passageway along its length, the device being approximately of its area. It has a metal-free portion between 10% and 50%, which provides a repeating pattern, design, or indicator along the length of the device, and at least some of the non-metallic portions are placed in metal across the device Completely surrounded by. 10% to 50% metal-free areas require 90% to 50% metal coating, which is preferably on one side of the security device but may be present on both sides, overlapping or not overlapping at all Will be understood. The security device may be a strip or seal having a width of 0.5 to 5 mm, preferably 1 to 3 mm, such as about 1.6 mm.

It is desirable for the metal free portion to provide language characters, such as English alphabet characters, and optionally, a wide variety of patterns or figures can be used if the strip or yarn always has at least one continuous metal passageway. The continuous metal passageway may be at one edge or both edges of the strip or yarn or in the middle of the edges or may vary from edge to intermediate point along the length of the strip. The strip or yarn may have parallel sides or have a nonlinear shape that is regular or irregular on one or both sides. The strip may be a plastic base partially covered with metal on one side thereof. Also, although not preferred, the strip or yarn may have metal on both sides of the plastic base, and the nonmetalized regions may overlap to provide a metal-free region of suitable dimensions.

The metal covering area is 55% or 60% to 90%, more preferably 60% to 85% of the strip or net area. In certain preferred embodiments of the present invention, the strip or yarn is positioned within a watermark or within a window or through-hole of paper in which the strip has no or substantially no paper fibers. Exposed.

In one embodiment of the present invention, dyes or fluorescent materials are present on one or both sides of the security device, which dyes or fluorescent materials may be the same or different when present on both sides of the strip or yarn.

The term dye generally includes coloring materials and includes pigments capable of coloring transmitted or reflected light. The term fluorescent material also includes other materials that emit characteristic radiation when excited by appropriate radiation, for example the term includes phosphors and other materials that emit characteristic radiation when excited by radiation other than ultraviolet.

In another embodiment of the present invention, the strip or yarn comprises a plastic substrate having a metal on one side, and a dye or fluorescent material is present in the plastic substrate or on the surface of the substrate. In addition, the strip or yarn may comprise a plastic base layer having a metal on one side and dye or fluorescent material may be present in the coating on the metal surface. The dye or fluorescent material need not be uniformly present on one side of the security device, even if a uniform layer is desired. Moreover, the strip or yarn may comprise a plastic base with metal on one side and a dichroic layer may be present on at least one side of the device.

An important feature of the present invention is that the counterfeit cannot simply mimic the effect of the continuous metallized portion of the yarn or line used in the present invention by simply drawing or printing. Although skilled printing is necessary for the printing used to mimic the safety paper according to the present invention, any printing may adequately mimic the significant contrast provided when a document or the like made from the paper of the present invention is tested in transmitted or reflected light. There is no number.

The safety paper described in US Pat. No. 4652015 is an attempt to achieve at least some of the benefits provided by the present invention. However, the present invention is a widely recognized very strong optical variable of a continuously metallized film due to the fact that the paper of the present invention is metallized in most areas of the strip or yarn and there is a continuous portion of metal along the length of the yarn. Because of its effectiveness, it is much more suitable for crushing counterfeiters and providing safety documents that are easily proven to the public. Banknotes made in accordance with the U.S. patent have weaknesses in imitation, for example, by typography using opaque white or cream ink on one surface of the paper, which may of course be incomplete but sufficient to deceive a large number of air. I knew it by experience. The optically variable effects of the metal letters used in the yarn of US Pat. No. 4,465,15 may not be exactly imitated, but some deficiencies in imitation can be easily overcome because the letters occupy only a portion of the yarn area. It will also be appreciated that the metal that is continuous along the yarns in the present invention significantly improves the ability to verify banknotes or other safety documents on the banknote classifier used.

The present invention also includes the method for producing a stable paper described above, which, when printed, is preformed during a continuous papermaking process to produce paper that yields a plurality of substantially identical paper portions that form substantially the same safety document, such as a banknote. Integrate the security device into the paper. The continuous papermaking process may use a Fourdrinier paper machine or a cylindrical mold paper machine. The method can actually use a cylindrical mold paper machine as described in EP 0 059 056 to produce a paper having windows and part of the security device in each window. In another method for producing a safety sheet, the security device is positioned continuously between two paper webs stacked together to form such a sheet.

It will be appreciated that the use of names, letters, geometric patterns, etc., significantly improves the security of the yarns used for papers having apertures or windows. The windows may be provided by methods known in the art other than those described in Applicant's EP 0 059 056. Another technique is to insert a strip or yarn between two layers of fibers that are formed separately on the paper machine and continue to move together to form a single sheet, whereby at least one layer is applied to the watermark or other method. It includes a series of holes formed by these holes (which contain no fibers at all) that are positioned to at least partially overlap the strip or shim to expose it.

If the holes are present in only one fibrous layer, the security strip or seal is only exposed or open on one surface of the final sheet. If the holes are present in both fibrous layers but in different positions, the strip or yarn is exposed or opened at different positions on both sides of the final sheet. If the holes are at least partially coincident with each other and present in both sides of the fibrous layer to coincide with the strip or yarn, the strip or yarn is simultaneously exposed on both sides of the sheet to form a perforation.

One of the most important benefits of using partially metallized yarns in which portions of the seals are exposed is to prevent forgery in making counterfeits using color copiers or syringes. This is explained more clearly in Example 8.

Banknotes and other safety documents made from the safety paper according to the present invention are virtually undetectable in reflected light, but appear as a strong highlight when the paper is viewed in transmitted light without the use of an assisting tool such as a lens. Incorporating the yarn, it is much darker than the pattern, figure or paper area adjacent to the yarn being displayed behind the metal. In addition, highlight areas that provide patterns, figures or indicators may be brighter than paper adjacent to the thread, for example, when relatively wide strips are incorporated into the paper during fiber attachment.

When dyes are used as a layer on one side of a security strip or thread, or when these dyes are incorporated into a plastic substrate to be metalized, the highlight area may be colored when irradiated with transmitted light and the color of the paper adjacent to the strip or thread. And can be quite different. Similar effects can be achieved when the added layer comprises a fluorescent material and the irradiation is carried out with transmitted UV or transmitted IR light or other irritating radiation. Another verification can be achieved by comparing a suitable safety paper according to the present invention in see-through in the transmitted white light and projecting the image with irradiating transmitted radiation. It will be appreciated that a safety document made from paper according to the present invention may be provided with two or more security strips described herein and the security strips may be the same or different from each other.

In one preferred embodiment of the invention, the nonmetallized zones, i.e. patterns, figures, signs, letters, etc., are individually completely surrounded by metal present along the edge of the strip or thread. In addition, the strip or yarn is made of a transparent plastic film partially metalized on only one side, and the continuous metal layer extends parallel to its central axis, especially along the two edges of the plastic strip or yarn.

The strip or seal can be uniform or fluctuating in width like any known security seal. For threads of uniform width, it is preferred that the width of the thread is 0.5 mm to 2.0 mm and the height of the character or mark (ie, the dimension across the width of the thread) is 0.3 mm to 1.5 mm. However, wider strips or seals may be used depending on the process used to incorporate the strips or seals onto the safety paper. The strips or yarns may be formed from a colorless transparent plastic film that is partially nonmetalized to provide a pattern, figure or indicator light, which is then cut to provide a strip or yarn, for example 1.2 mm wide.

According to the invention, a more variable and visible effect can be obtained when providing a uniform dichroic film coating on one or both sides of a partially metalized strip or yarn before inserting it into paper. The perception of the metallized highlight area changes color depending on the perspective angle and / or the direction of irradiation. When the dichroic material is positioned under a window formed in paper so that the dichroic coating of the strip or yarn is exposed, the visual effect using the dichroic strip or yarn is enhanced.

Banknotes or other safety documents made from the safety paper according to the present invention incorporate strips or seals that provide an electrically conductive passageway extending along the length and width of the paper. Such strips or threads can therefore be detected using conventional metal thread detection devices, such as the banknote classifier used, for example. This property of the seals or strips of the invention detectable with conventional metal seal detection devices is absent in the case of banknotes or other safety documents made in accordance with US Pat. No. 4652015. In addition, by providing a suitable detector, the distribution of metal in the strip or stall can be determined by electrical, optical or other means and compared with a reference pattern to provide another technique for authenticating the authentic document embedded with the strip or seal.

In addition, if the metal and / or highlight area is colored or a fluorescent coating is provided according to one of the techniques already described, providing a suitable irradiation and detection device to strip colored metal and / or highlight area. Alternatively, it can be compared to a reference pattern as another technique for authenticating authentic documents incorporating seals.

Description of embodiments of various safety papers according to the present invention will be described later.

Example 1

In one embodiment of the present invention, a partially metalized colorless transparent plastic film, as described above, is cut into a typically 1.2 mm thick yarn, where the metal content forms 67% of the yarn area. Since the thread is inserted into the paper, for example on a cylindrical mold paper machine, the total number of grams of paper above and below the thread is considerably less than the number of grams of paper adjacent to the thread and is provided by the non-metalized portion of the thread in the paper. Highlight areas are brighter than the paper area adjacent to the thread when viewed in transmitted light.

Example 2

In another embodiment of the present invention, a layer containing dye or fluorescent material is uniformly coated on the metal-free side of a partially metalized colorless transparent plastic film as described above. The film is then cut to form a thread and the thread inserted into a paper. When the paper is projected in the appropriate reflected light (visible, UV or IR), the coated side will have a uniform color, whereas only the highlight area will be colored on the uncoated side. In transmitted light, only the highlight area is colored, no matter which side faces the viewer.

Example 3

In another embodiment of the present invention, the colorless transparent plastic film is partially metalized as described above and uniformly coats the layer containing dye or fluorescent material on one side and the other side uniformly with another material of different color. do. The film is cut to form a thread and inserted into the paper. Within the reflected light, each face exhibits a nearly uniform color of its own particular color, although there may be some color blending within the highlight area. However, within the transmitted light, the highlight area is perceived as a third color that is distinct from those colors by a mixture of the other two colors.

Example 4

In another embodiment of the present invention, the colorless transparent plastic film is partially demetalized by the chemical corrosion and etching process as described above, covering the metal area that needs to be maintained by this process to position the resist and remove the metal. Can be doped with dyes or fluorescent materials. Thereafter, the film is cut to form a thread and inserted into the paper. If such a sheet is projected through a metallized side within the proper reflected light, only the metallic area will be colored and the highlight areas will not be colored. When the paper is viewed from the non-metalized side of the thread, no color is seen.

Example 5

In another embodiment of the present invention, a colorless transparent film is partially nonmetallized with a resist comprising a dye or fluorescent material and uniformly coats a material containing colored dye or fluorescent material according to the nonmetalized side do. Thereafter, the film is cut to form a thread, and the thread is inserted into paper. When the paper is projected from the non-metalized side of the yarn in reflected light, uniform color is observed. When the paper is viewed from the metallized side of the yarn in the reflected light, the metal region has one color and the highlight region has a second color. When the paper is viewed in transmitted light, only the highlight area is observed in the color of the nonmetallized face coating, regardless of which side of the yarn is facing the viewer.

Example 6

Example 2 was modified by incorporating a dye or fluorescent material into the plastic material prior to metallization. A visual effect similar to Example 2 was obtained when a partially non-metalized yarn with dye or fluorescent material in the plastic substrate was inserted into the paper.

Example 7

In another embodiment of the present invention, a dichroic coating is applied on one or both sides of a colorless transparent plastic film that is partially nonmetalized as described above. The color of the metalized highlight area changes with the perspective angle and / or the direction of irradiation.

This embodiment is improved when used for paper having windows or through holes.

Example 8

In another embodiment of the present invention, the transparent plastic film described in any one of Examples 1 to 7 is cut to form a seal and on one side of the paper sheet according to the technique described in EP-B-0 059 056. Insert into the paper so that the surface of the seal is exposed at predetermined intervals. The presence of highlight areas of partially metallized seals in areas of the paper where the seal is exposed or opened on the surface of the paper greatly increases the difficulty in imitating the appearance of the exposed areas and improves the overall safety of the document. In transmitted light, the striking metal strip appears to be very clearly contiguous, but two windows in which the agitated exposure area of the metallized yarn and the yarn are substantially invisible when viewed in front of the paper, ie the open surface in reflected light. There is a very rapidly changing contrast between the metallized regions embedded in the fiber crosslinks between them. The overall benefit of the colorants or fluorescent agents described in Examples 2-6 is most evident when the security seal is used for paper in the form of a window as described more fully in Example 12.

The advantage of using partially metallized yarns of the structures described above is very important in terms of protection against counterfeits. When a banknote or other document containing a security seal manufactured according to the present embodiment is reproduced on a color copying machine or a laser syringe, the metallized area of the security seal in the exposed area is duplicated in black or dark areas and the highlight areas are white or dark. Replicated to bright areas.

In order to imitate the appearance of the original printed document, the counterfeiter should then use some means to provide a metallic appearance in the appropriate area and highlight areas should remain clear. This is a complex and tedious task and is more difficult than mimicking the appearance of a fully metalized security seal. Therefore, the paper produced according to this embodiment has improved the safety for counterfeits produced using a color copying machine or a laser syringe.

Example 9

In another embodiment of the present invention, the transparent plastic film according to any of Examples 1 to 7 is cut to form a yarn, and the yarn is inserted between two layers of fibers formed independently on the paper machine before being moved together. . A watermarking method is used to form areas in one of the fibrous layers or to have no fibers, ie to form holes, in which the fiber thickness is reduced to a very thin layer locally. Optionally, a series of holes is formed in one of the fibrous layers by water spray or some other means. The thread is placed through the hole or thin area such that the seal is substantially or completely exposed at predetermined points on one surface of the final paper sheet.

Example 10

In another embodiment, Example 9, except that a series of holes or thin fibrous layer areas are formed in the two layers of paper prior to moving the two layers of paper together such that the yarn is exposed to predetermined points on both sides of the final paper sheet. A method similar to the method described in the above is used.

Example 11

In another embodiment, the thin layers or holes of the two layers are at least partially coincident and coincident with the thread, except that the thread is simultaneously exposed at predetermined points on both sides of the sheet, ie the thread passes through one or more holes. Uses a method similar to that described in Example 10.

Example 12

In another embodiment of the present invention, the colorless transparent film is partially demetalized with a dye or a resist containing fluorescent material to uniformly coat the nonmetalized side with a material containing a dye or fluorescent material of a different color. . The film is then cut to form a thread and inserted into the paper such that areas of the thread are exposed on one surface of the sheet according to the technique described in EP-B-0 059 056.

When the metallized side of the yarn is exposed to the window of the paper, seeing that side of the paper in reflected light results in a very strong contrast between the metallized area due to the colorant in the resist and the colored highlight area due to the colorant in the uniform coating. This exists, and its contrast is more dramatic in those areas between the windows if the threads are covered with fibers on both sides. Within the transmitted light, only highlight areas that are colored because of the uniform coating colorant are observed and the window area where one side of the yarn is exposed appears brighter than between the windows where both sides of the yarn are covered with fibers.

If the non-metalized side of the yarn is exposed in the windows of the paper and sees that side of the paper in the proper reflected light, the yarn has a nearly uniform color that is brighter in the window area than between the windows covered with their fibers.

Within the transmitted light, too, only the highlight areas are colored because of the colorant in the uniform coating and appear brighter in the window area than between the windows.

Instead of using a uniform coating on the nonmetalized side of the yarn, dyes or fluorescent agents can be incorporated into the plastic film to achieve the same effect.

This pronounced effect draws attention to the presence of highlight areas in the partially metallized strip and greatly increases the difficulty of imitating the metallized security chamber in the paper where the thread is exposed to the window.

The accompanying drawings show a security seal that can be used in accordance with the present invention. The security seals are presented in an enlarged form, and in use they are usually 1.2 mm wide. All the seals are formed by demetallizing the deposited aluminum supported on the polyester film. The aluminum is removed by using corrosion and etching techniques.

The metal content of the yarns shown in the figures is shown in the following table.

[table]

Banknotes formed of yarns as shown in FIGS. 1-8 provided significant stability (when inserted into banknote paper) and the threads read exceptionally by viewing in transmitted light without the use of lenses or other visual aids. It provides public safety characteristics because it is possible. When looking through banknotes with reflected light, I could hardly see the threads. 8 shows a yarn having a geometric shape. It may be formed by a mechanical stamping / cutting machine or a laser such as an excimer or carbon dioxide laser. Instead of cutting the non-metalized film, the film can be cut into any shape and then demetalized with an excimer laser that acts on the cut yarn (this technique can also be used for yarns with parallel faces). Patterns, figures, and indicators of security devices can be recognized by the public without using special vision aids, such as magnifying glasses, and thus documents containing such devices can be recognized as authentic documents.

It will be appreciated that the plans and purposes of the threads in a banknote according to the invention are the same and therefore the banknotes are the same for a given kind or publication. It is easy to have a regular manufacturing error, for example, for indications such as PORTALS, there is no machine direction indication technique, and any part of the message may exist with respect to the top or bottom of the banknote. This is in full agreement with the practice of the microprinting chambers normally used.

The terms safety paper, safety paper, and banknotes herein refer to parts made entirely of natural fibers (e.g., cotton or wood), partly natural fibers, and in part synthetic fibers (e.g., nylon, polyvinyl alcohol, viscose). It will be appreciated that the invention includes articles made from and products made entirely from synthetic fibers (eg, spunbond polyolefins, polypropylene).

Safety documents, including partially natural fibers and synthetic fibers, may be made from paper formed by making an aqueous mixed dispersant of such fibers, for example for use on conventional paper machines such as cylindrical paper machines or Podrinier machines, and security strips. Or another security device is inserted according to known processes. Alternatively, it may be fabricated on a multiple ply former, which forms one or more plies entirely from natural or synthetic fibers, with a security device inserted between the plies at the points where the plies are joined together. Another method involves laminating a dry sheet completely or partially formed of one type of fibers (such as synthetic fibers) to another dry sheet completely formed of another type of fibers (such as natural fibers) using a suitable adhesive and stacking the security device. To insert it at the point.

The safety document according to the present invention, which comprises completely synthetic materials, can be formed of synthetic fibers in a manner consistent with conventional papermaking processes. Optionally, a sheet or web of synthetic material, such as polypropylene, for example, is laminated to another sheet or web of the same or another synthetic material using a suitable adhesive and inserted into the final layer, for example by incorporating a security device, which is a strip, at the lamination point. can do. Still other suitable processes will be apparent to those skilled in the art.

The partially metallized film mentioned herein is preferably formed by, for example, depositing aluminum or another metal on a plastic film according to one of the techniques described herein. However, it is also possible to use plastic substrates coated or printed with special metal inks, such as Metasheen from Crawley, Sussex, Crawley, UK, currently sold under ink code SLS 34. Metasine inks result in highly reflective surfaces and are also conductive. When the security strip is irradiated with appropriate stimulus radiation, the dye or fluorescent material may be incorporated such that the metallized area is observed as a colored area in complete coincidence with the printed metallized area formed with the metacine ink. It will be appreciated that other inks that impart a metallic appearance and provide a conductive layer can be used in accordance with the present invention.

Claims (16)

A security device comprising at least two sides to be printed to prove that it is a document made of safety paper, and having a flexible, impervious base having a metal layer on one or both sides as a public safety feature between the two sides of the paper, at least In a partially positioned safety paper, the security device has a width of 5 mm or less and on one side of the device there is a substantially continuous metal passageway along the length, the device having a 10% to 50% area free of metal parts. Wherein the non-metallic portion provides a repeating pattern, figure or indicator along the length of the device and at least some of the non-metallic portion is completely surrounded by metal across the transverse direction of the device paper. The paper of claim 1, wherein the security device is a strip or thread having a width of 1 to 3 mm. The paper of claim 1 or 2, wherein the non-metallic portion provides language characters such as the English alphabet. The paper of claim 1 wherein the area of the metal free portion is between 10% and 45% of the strip or seal area. 5. The paper of claim 4, wherein the area of the nonmetallic portion is from 15% to 40%. 2. The paper of claim 1 wherein the strip or seal is located within a watermark. The aperture of claim 1 wherein portions of the strip or thread are located in a window with no or substantially no paper fibers in the strip or thread or a portion of the strip or thread partially or completely coincides with the two windows. A container located within. The paper of claim 1, wherein the dye or fluorescent material is on one or both sides of the security device, and the dye or fluorescent material may be different when present on both sides of the strip or yarn. The paper of claim 8, wherein the strip or yarn comprises a plastic substrate having a metal on one side and a dye or fluorescent material present in or on the surface of the substrate. The paper of claim 8, wherein the strip or yarn comprises a plastic substrate having a metal on one side and a dye or fluorescent material present in the coating on the surface of the metal. The paper of claim 1, wherein the security device comprises a plastic substrate having a metal on one side and a dichroic layer present on at least one side of the device. The paper according to claim 1, wherein the paper is made of soluble fibers or synthetic fibers and natural fibers or by laminating two or more sheets of synthetic material and the security device is positioned between the two sheets. The safety claimed in claim 1 incorporating a preformed security device in the paper during a continuous papermaking process that produces a paper capable of securing a plurality of substantially identical parts that are printed to form a substantially identical safety document such as a banknote. How to make paper. The method of claim 13, wherein the continuous papermaking process uses a Fourdrinier paper machine or a cylindrical mold paper machine. The method of claim 13, wherein the security device is continuously positioned between two paper webs stacked together to form a safety paper. A banknote or other safety document made from the paper claimed in claim 1.

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