KR940008054B1 - Security paper for currency and banknotes - Google Patents

Abstract

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Description

Securities paper and its formation method

1 is a plan view of a bank note with a safety device according to the invention.

FIG. 1A is a partially enlarged plan view of the bank note of FIG. 1 showing an easy-to-read phrase of a safety device illuminated by transmitted light.

Figure 2 is a partial cross-sectional side view of a telescopic machine with a funnel tube drawing a safety device from a continuous strip into paper fibers.

3 is a partial cross-sectional side view of a cylindrical paper machine for inserting a safety device from a continuous strip into paper fiber.

4 is an enlarged perspective view showing a portion of the aluminum plated polyester safety device strips shown in FIGS. 2 and 3 after the transparent protective film is applied to the aluminum plated print.

5 is a perspective view of an aluminum-plated polyester safety device film after a transparent protective film is applied to the area where the marking is held and a corrosion solution is applied to the unprotected area to form a soluble aluminum salt.

FIG. 6 is a perspective view showing the stabilizer film of FIG. 5 after the corrosion solution is applied and the soluble aluminum salt is removed. FIG. And

7 is a side sectional view showing the safety device of FIG. 6 embedded in a paper formed in the paper machine shown in FIGS. 2 and 3 according to the present invention.

* Explanation of symbols for main parts of the drawings

2: outlet 3: head box

7: securities paper 10: securities

11: plastic strip 12: safety indicator

13: safety strip 14: tube

15 fiber slurry 16 paper machine

17: paper machine wire 18: paper machine

20: cylinder 23: felt

25,26: paper fiber 28: polyester film

29: aluminum layer 31: metal letters

Various methods can generally be used to embed thin strips of transparent material, such as polyester films, in paper during the paper making process. If the film is used as a security thread and first microflinted before being dispensed during the papermaking process, the final bill contains a readable code that can be read by transmitted light. In the case of paper of thickness and substrate used for money and bank drafts, the sign can be seen under transmitted light. The purpose of the printed safety seal is to prevent potential forgery by making the encoded markings of the seals embedded in the bills so that they cannot be reproduced by surface printing techniques. The reliability of such documents can be easily proved by comparing the appearance of the safety chamber under reflected light with that under transmitted light. When dealing with money and bills in general distribution, the reflection of the public is the most trusted. However, the reflected light appearance does not directly reveal the presence of a print that is completely readable in the transmitted light. Indeed, the unclear thin line of suspicious safety seals on the surface of money and bills appear obvious to the public.

Incorporating safeguards in the body of securities paper requires sophisticated paper machines that are not available to counterfeiters. One method of incorporating a safety device is disclosed in William's US Pat. No. 3,880,706, where the safety device is sandwiched between two paper layers formed during the paper manufacturing process.

Opaque items embedded in securities paper are also already covered in US Patent No. 210,089; 964,014; And 1,929,828. Since the two-ply papers could possibly be duplicated by laminating thin sheet of counterfeit papers without the need for elaborate papermaking, the two-ply insertion method disclosed in the patents is unlikely to be used in currency paper. The simple construction and design of the previously proposed safety items made it possible for counterfeiters to copy without incurring huge technology and costs.

Another method of incorporating a safety device in securities papers is to compress the safety device into wet paper fibers while the fibers do not harden and are flexible, as disclosed in US Pat. No. 4,534,398 to Timothy Crane, which is incorporated herein by reference. have. In this way, the safety device is made visible on one side of the stock sheet for visual confirmation.

US Pat. No. 4,522,617, in the name of Timothy Crane, discloses a method for incorporating a safety device in a stock sheet such that the safety device support layer can be disassembled so that the safety device can be visually accessed from one side of the stock sheet.

All of the above-mentioned methods of incorporating safety devices in securities papers make it possible to visually know the presence of safety devices even with the naked eye. According to the William's method, the observer may believe that a faint line on the surface of a stock sheet, for example, is a sufficient indication of authenticity, without the paper having to be held up to transmitted light for practical demonstration. In the early days of safeguards, the thickness of the securities paper area near the safeguards increased compared to the thickness of the paper itself. This increased thickness or "unblocked" line can be duplicated by skilled counterfeiters, allowing the observer to believe that the safety device is indeed present without further inspection.

As disclosed in the aforementioned William patent, when an unprinted metallized plastic seal is used as a safety chamber, the optical and electrical properties of the seal can be used to determine optical changes over the paper and automatically identify by standard electronic metal detection techniques. have. However, the optical properties of such a metallized yarn can be duplicated to some extent by faint or opaque lines printed on the surface of the paper near the location of the safety seal. A blunt pencil line can also trick an unskilled observer into the presence of a buried safety chamber.

For reliable confirmation, money or notes must be held up to the light source to reveal the markings encoded on the safe room so that the safe room is actually counterfeit. In addition, opaque lines, which are visible surface phenomena for embedded safety chambers under reflected light, are easily simulated by various printing methods.

Previous attempts to print on plastic strips and embed the strips in paper have not been used so far because the ink used to form printed information readable under transmitted light allows the information to be read under reflected light. . Then, the general public can know the existence of the print only under the reflected light, and such print can be easily copied by the counterfeit means.

One way to ensure that the public does not depend on the safety room characteristics that are easily simulated is to make money and paper containing safety seals that do not indicate that there is a safety seal on the money or bill surface and which are not actually visible under reflected light. There has been no way to test the reliability twice, which is readable under transmitted light and not visible under reflected light.

It is therefore an object of the present invention to provide a method of including a safety seal in a stock sheet containing printed information so that it can be easily read under transmitted light but cannot be actually detected when reflected by reflected light. Another object of the present invention is to provide printed information at a specific position within the stock sheet and to produce the paper economically and at high speed using modern manufacturing techniques.

The present invention provides a method of encrypting information printed on a transparent plastic film strip included in a paper during the paper making process. The printed information can be read by eye or detected by machine. The detection method utilizes the difference in optical density delivered, the difference in capacitance, the amount of current change in the tuned resonant circuit, and the like.

The encrypted information is confined in a narrow strip on a plastic film that can be accurately placed in money, bill or stock paper while maintaining the speed of modern paper making equipment. In one embodiment, the printed information is a readable phrase, the letters being 300-400 angstroms thick and composed of vacuum deposited aluminum metallized metal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The securities paper of the present invention can be applied in the form of bills or currencies, such as the US Reserve Bank Securities (10), the securities (10) and the numerical display (5) indicating the face value of the securities as shown in FIG. Together, it is a rectangular sheet of paper (7) containing a portrait (6) of the former President of the United States. The plastic strip 11 is embedded in the paper in the manner described below in detail. Strips extending in the direction defined by the parallel dotted lines are not easily visible on the surface of the paper under the reflected light of the naked eye. The strip itself has a flat shape that cannot be touched, unlike the safety seals used in some European currencies.The safety seals used in European currencies warp the surface slightly, so you can actually feel it when you rub the paper between your fingers. have. Although it is difficult to find the safe seal of a new currency under reflected light, the existence of the conventional safe seal is easy to be exposed by the unobtrusive outline of the safe seal that appears in the course of handling the money repeatedly. For example, careless cashiers were fooled by carefully drawing soft pencil lines in the same locations where they would expect to find a safety seal. Since the plastic strip 11 of the present invention has a flat shape, the presence of the strip is not detected continuously under the reflected light even after long use. When the check is illuminated over a floodlight source or passed over a "light table" consisting of a transparent surface over a powerful light source, the safety sign 12 shown in FIG. 1A is easily visible.

The concept of embedding a safety device in the paper fiber of a long paper machine is explained in the above-mentioned US patent of Timothy Crane, and the long paper machine 16 is shown in FIG.

The head box 3 comprises a slurry 15 composed of a mixture of cellulose fibers and a filler. All these mixtures are contained in a water container indicated by dashed line (8). The safety strip 13 passes from the rail (not shown) through the tube 14 and is continuously transferred into the slurry at the outlet 2 of the head box and fed onto the paper machine wire 17. As the slurry is dehydrated and solidified during the paper making process and proceeds along the wire, the fibers continuously surround the safety strips. Once the paper has reached the final stage of dehydration, it is passed through a pressing and drying heating roller to become a finished paper product. The position of the tube 14 at the lateral extension of the wire 17 accurately determines the predetermined position of the safety strip in the finished paper product.

The concept of embedding a safety device in the paper fibers of a cylindrical papermaking machine is described in the aforementioned patent of Timothy Crane, such cylindrical papermaking machine 18 is shown in FIG. Slurry 15 contains paper fibers 26 of the same composition in water 27 as already described for the slurry of FIG. After some paper fibers have been collected on the screen 26 ′, the safety strip is transported over the screen 22 of the cylinder 20 via a guide roll 19 in a rail (not shown). The solidified paper fibers 26 containing the safety strip move in the direction of the arrow over the guide roll 24 over the couch roll 21 and in the opposite direction again in the heating and pressing steps of the paper making process. Felts 23 that move to form the securities paper recovered from the cylinder 20.

The length 30 of the safety strip 13 shown in FIG. 4 consists of a polyester film 28 shielded with a vacuum deposited aluminum layer 29 forming a flat aluminum film surface 29A. The letter " CRANE " 31 is printed on the aluminum surface by a corrosion resistant ink varnish. When a metal that is molten in acid, such as tin, is deposited on a polyester film, acid resistant ink varnishes are used to print text. A safety strip of the same length 30A is shown in FIG. 5, in which the unprotected area of the aluminum-coated surface 29A is covered with a number of cross-shaped portions 32 which should be removed by contact with an aqueous solution of corrosive sodium hydroxide. Indicates aluminum metal. Corrosion-resistant ink varnishes protect the metal surface under the varnish from contact with corrosive substances.

Even if the varnish is effective to prevent the metal from being decomposed by the caustic sodium hydroxide solution, the fine print is best protected from being decomposed by the sodium hydroxide solution if the contact with the sodium hydroxide solution is as short as possible. Sodium aluminate salts formed by reacting unprotected aluminum with sodium hydroxide solution are washed off well from the surface by applying a clean water cleaner.

In the same length 30B of the safety strip shown in FIG. 6 all aluminum is removed from the surface of the polyester film 28 to reveal a flat polyester surface 28A. After the molten metal is removed, the letters 31 remain completely on the surface. Other methods of attaching letters to surfaces may also be employed without departing from the concept of the present invention. Codes in readable print or optically readable bar form may be applied by direct heat stamping to the polyester surface or through selective metallization using a mask or template in a vacuum metallization apparatus. Not only can various metal inks be used to print directly onto the polyester surface, but they are also employed where the size of the type is large enough that fine line sharpness is not essential. Securities paper 25 in FIG. 3 containing a safety strip 13 embedded after heating and pressing is shown in FIG. Since the paper fibers 27 completely surround the safety strip, the safety strip is not visible on either side of the stock sheet. The thickness of the paper is uniform and there are no blocks near the paper containing the safety strips. This is an important feature of the present invention for the reasons mentioned above. Although the metal letters 31 on the plastic strip 11 are embedded in the paper fibers, they are easily seen when light is transmitted from one side of the stock sheet, and the metal is 300-400 angstroms thick and the 4 × 10 ^-3 -6 × 10 ^-3 inch (i.e., 0.10-0.15mm) when the thickness is shown in the opposite side of the stock paper.

Thus, a flat plastic film that provides mechanically readable codes or visually readable letters can be embedded in predetermined positions of money and bills so that they can be identified by transmitted light. The sign is invisible to the naked eye under the reflected light on either side.

Claims (22)

Providing a continuous plastic film having a metal mark on at least one surface, wherein said metallized in said paper fiber slurry at said position in said paper fiber slurry while dewatering said paper fiber slurry before said fibers harden into a continuous paper web; Inserting a plastic film, stiffening the paper fibers into a continuous paper web having a metallized plastic film embedded within the paper web, and between the opposing first and second surfaces And heating and compressing the paper web and the metallized plastic film to form a finished paper with a plastic film, such that the metal mark cannot be perceived by the naked eye under reflective illumination and the surfaces are in place at predetermined positions. Stock paper formation method that is easy to read under the transmitted light. The method of claim 1, wherein the plastic is made of polyester and the metal is made of aluminum. 3. The method of claim 2, further comprising forming the finished paper from a plurality of rectangular laminations having a pair of opposing first sides longer than a pair of opposing second sides to form a rectangle. And a plasticized plastic film extends along the rectangle parallel to the second opposite sides. A safety strip that provides a means to prove authenticity on securities paper, such as bank drafts, wherein the markings formed of metal include plastic strips formed using an optional metallization process, a heat stamping process, or an optional demetallization process. Safety strips. (a) a rectangular paper sheet having both first and second surfaces flat and of constant paper thickness and length, (b) a printed mark readable on the surfaces under reflective illumination to identify the subject of the paper, And (c) a safety strip disposed between said first and second surfaces to provide a means of authenticating said paper, said plastic strip having a mark formed of metal, said mark being an optional metal. Formed on the plastic strip using a coating process, a heat stamping process or an optional demetallization process, wherein the marking formed of the metal consists of a safety strip which cannot be detected under reflected light but is easy to read under transmitted light through both surfaces; Stock paper, said paper thickness is uniform along the paper length. 6. The method of claim 4 or 5, wherein the metal is a metal that is susceptible to acid dissolution, and wherein the optional demetallization process involves (a) vacuum depositing the metal onto the plastic strip, and (b) applying an acid resistant ink varnish. Forming the mark on the strip, and (c) contacting the strip with an acid solution. 6. The method of claim 4 or 5, wherein the metal is a metal soluble in a corrosive solution, and the optional demetallization process comprises (a) vacuum depositing the metal onto the plastic strip, and (b) corrosion resistant ink varnish. Applying to form the marking on the strip at all times, and (c) contacting the strip with a corrosive solution. The safety strip of claim 6, wherein the metal is vacuum deposited to the plastic strip to a thickness of about 200 kPa to about 400 kPa. The safety strip of claim 15, wherein the metal is vacuum deposited to the plastic strip to a thickness of about 270 kPa to about 310 kPa. 6. A safety strip according to claim 4 or 5, wherein the marking formed of metal is defined by boundaries without metal. 6. A safety strip according to claim 4 or 5, wherein the marking formed of the metal is defined by metal boundaries. 6. A safety strip according to claim 4 or 5, wherein the mark formed of the metal is an alphabetic character. 6. A safety strip according to claim 4 or 5, wherein the mark formed of the metal is a number. 6. A safety strip according to claim 4 or 5, wherein the mark formed of the metal is a letter and a number. The safety strip of claim 7, wherein the metal is vacuum deposited to the plastic strip to a thickness of about 200 kPa to about 400 kPa. The safety strip of claim 15, wherein the metal is vacuum deposited to the plastic strip to a thickness of about 270 kPa to about 310 kPa. A safety strip according to claim 10, wherein the mark formed of the metal is an alphabetic character. 12. The safety strip of claim 11, wherein the mark formed of metal is an alphabetic character. A safety strip according to claim 10, wherein the mark formed of metal is a number. 12. The safety strip of claim 11, wherein the mark formed of metal is a number. The safety strip of claim 10, wherein the markings formed of metal are letters and numbers. The safety strip of claim 11, wherein the markings formed of metal are letters and numbers.

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