JP2008196096A - Anti-counterfeit paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-counterfeit paper obtained by mixing a transparent hollow fiber unit in which filaments each composed of a magnetic material are included into a paper and excellent in long-term maintenance of visibility and responsiveness to magnet. <P>SOLUTION: The anti-counterfeit paper is obtained by mixing a transparent hollow fiber unit in which filaments each composed of a magnetic material having 10-10<SP>5</SP>relative permeability into a paper. In the anti-counterfeit paper, both of the visibility and the responsiveness to magnet are satisfied by optimizing size, shape and magnetic properties of magnetic filaments. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an anti-counterfeit paper in which a transparent hollow fiber unit containing a filament made of a magnetic material is mixed in paper. In particular, the present invention relates to an anti-counterfeit paper formed by dispersing the transparent hollow fiber unit with pulp fibers and dispersing it on the entire surface of the paper.

Counterfeiting securities is a major social problem, and various measures against forgery have been taken so that banknotes, gift certificates, checks, stock certificates, passports, ID cards, cards, etc. cannot be illegally altered or forged. Yes. Counterfeit prevention measures can be roughly divided into two as described in Non-Patent Document 1. Everybody can judge the authenticity of the object clearly with his own power, “Visible anti-counterfeiting measures that are visible to the public” (Obert), and authenticity cannot be judged without using dedicated equipment. This is an undisclosed “invisible, non-public anti-counterfeiting measure” (Cobert).

Obert is something that the general public who directly gives and receives counterfeit goods needs to know. Therefore, it is preferable to use an easy-to-determine technique that can immediately determine the authenticity using the human senses without using a tool that requires a complicated operation.
In the paper field, watermark is a typical overt technique. Watermark technology is widely used for banknotes, securities, and passports. As another overt technique, there is a method of mixing a special substance into paper. Paper mixed with display materials such as colored fibers and fluorescent light-emitting fibers as special substances is used for paper such as securities.

On the other hand, the covert is generally judged by an expert while keeping secrets other than those involved, and in many cases using special equipment. The covert technology also includes authenticity determination technology using equipment such as bill processing equipment such as vending machines and ATMs.
The covert technology related to paper includes its own independent method such as printing with infrared ink, but many techniques are an extension of the overt technology. For example, when a special substance is mixed in paper, a substance that cannot be generally detected such as a rare metal is mixed. In addition, there is a method in which metal fibers, magnetic materials, and the like are mixed in the paper layer, the distribution state is recorded in a computer, and then detected and collated in authenticity determination. As the special substance mixed in the covert, information recording materials such as metal fibers and magnetic materials are generally used. Therefore, it can also be used for traceability.

In recent years, it has become possible to make counterfeit banknotes relatively easily by improving the performance and price of computers, scanners, printers, etc., and counterfeiting by amateurs who are not professional counterfeit groups is increasing. Therefore, there is an increased opportunity for the general public to contact counterfeit banknotes (although not so elaborate), and it has become necessary for them to authenticate the banknotes themselves. Under such circumstances, the importance of overt technology that can be distinguished by anyone is increasing beyond hidden anti-counterfeiting technology such as covert.

For the purpose of preventing forgery of a paper or film-like medium, forgery as in Patent Document 1 in which a transparent hollow fiber unit (hereinafter referred to as a transparent hollow fiber unit) containing some display material and / or recording material is mixed. Prevention paper has been proposed.
The form of the anti-counterfeit paper in Patent Document 1 is shown in FIG. The transparent hollow fiber unit 310 includes a display material and a recording material (hereinafter referred to as an inclusion substance) 311 and a transparent hollow fiber 312. In FIG. 3, black particles are illustrated as the inclusion substance 311. For example, when the black particles are magnetic powder, the magnetic powder is observed as a display material inside the transparent hollow fiber unit in the state of 310a, so that an overt function is exhibited. There is also a unique effect that the magnetic powder moves by bringing the magnet closer.
On the other hand, since the transparent hollow fiber unit in the state of 310b is inside the paper layer (see the sectional view of FIG. 4), there is no overt function. However, since it contains magnetic powder, it functions as a recording material detected by a magnetic sensor or the like and exhibits a covert function. Further, in order to improve the overt function inside the paper layer, that is, the visibility, Patent Document 2 discloses a technique for encapsulating a fluorescent dye or the like in a transparent hollow fiber.

Further, anti-counterfeit paper called threaded paper is also a type of overt, and is often used for banknotes in various countries. The form of the thread to be baked into the paper layer is generally about 10 to 100 μm thick and is a thread or tape with a width of 0.2 to 30 mm. For example, gold thread, silver thread, plastic film, metal vapor deposition film Etc. are used.

There are two types of threaded paper. The thread is embedded in the paper layer and is not exposed on the paper surface, and the other is a paper with a window opening thread in which a part of the thread is exposed on the paper surface. The latter is characterized in that a window opening portion having a thickness reduced intermittently in the sheet flow direction is formed, and a thread is exposed at the window opening portion. Therefore, the window opening type generally has a higher overt effect. Further, in order to further enhance the forgery prevention effect of such threaded paper, a window is formed in the window opening portion of the paper with a window opening thread (see Patent Document 3), or a micro evaporation layer formed of a metal vapor deposition layer on the thread surface. In some cases, characters and micro-images are formed.

The above-mentioned conventional threaded paper is a technology for making a thread, a technology for intermittently exposing a thread to a window opening, a technology for making a window opening, a technology for forming a micro character or a micro image on a thread. Therefore, it is preferably employed as a forgery prevention means.
However, in order to further enhance the anti-counterfeit effect of the conventional anti-counterfeit paper that incorporates threads, fusion with the above-described transparent hollow fiber technology has also been proposed. In the anti-counterfeit paper described in Patent Document 4, transparent hollow fibers that have penetrated the paper as short fibers are inserted as threads. The anti-counterfeit paper including the transparent hollow fiber unit as a thread includes a number of elements that are difficult to forge, such as production of transparent hollow fibers, inclusion of display materials and recording materials in the transparent hollow fibers, and threading. It is preferable as an advanced anti-counterfeiting means.

Advanced Anti-Counterfeiting Technology -Case Examples-, Technical Information Association, p. 5-18 (2004) Japanese Patent Application No. 2005-370641 Japanese Patent Application No. 2006-204264 Japanese Patent Laid-Open No. 9-316796 Japanese Patent Application No. 2006-297469

The production of anti-counterfeit paper and threaded paper mixed with the transparent hollow fiber unit containing the display material and recording material described above is preferably used as anti-counterfeiting means because high technology is required.

However, these anti-counterfeiting measures still have technical problems from the long-term stability and viewpoint. That is, when a liquid is used in combination, the internal liquid from the transparent hollow fiber leaks or the internal liquid evaporates. In a system in which fine particles are dispersed in a liquid, the fine particles are aggregated or settled. Furthermore, since the fine particles move as dots, they may be difficult to visually recognize. The decrease in internal liquid over time, aggregation and sedimentation of fine particles, and difficulty in visual recognition due to fine particles are all factors that lead to a decrease in visibility. The present invention provides an anti-counterfeit paper that can maintain visibility for a long time.

The present invention provides a novel anti-counterfeiting means called anti-counterfeit paper containing a transparent hollow fiber unit containing a filament made of a magnetic material. In the present invention, an internal solution is not required, there is no fear of agglomeration, and a filament excellent in visibility that moves by a line instead of a point is used. That is, the present invention includes the following configurations (1) to (6).

(1) An anti-counterfeit paper characterized in that at least one transparent hollow fiber containing a filament made of a magnetic material is mixed in paper.
(2) An anti-counterfeit paper characterized in that the transparent hollow fiber is inserted into paper as a thread.
(3) The anti-counterfeit paper according to (1) or (2), wherein the filament has a diameter in a range of 10 μm to 300 μm.
(4) The forgery prevention paper according to any one of (1) to (3), wherein the filament has a length in a range of 1 mm to 30 mm.
(5) the relative permeability of the said filaments, anti-falsification paper according to any one of the range of 10 to 10 ⁵ (1) to (4).
(6) The anti-counterfeit paper according to any one of claims 1 to 5, wherein the filament is made of a stranded wire.

According to the anti-counterfeit paper according to the present invention, it is not necessary to use a liquid together with the inclusion, and thus long-term visibility can be maintained. In addition, unlike a particle, a filament moves as a line rather than a point, so the effect of improving visibility is high. Therefore, it is possible to provide a more advanced and reliable means for preventing forgery.

The present invention will be described in detail below.
A conceptual diagram of an example of the anti-counterfeit paper of the present invention is shown in FIG. 1, and a cross-sectional view is shown in FIG. As shown in FIGS. 1 and 2, the anti-counterfeit paper 100 is formed in a state where a transparent hollow fiber unit 110 containing a filament made of a magnetic material is mixed in paper.

The transparent hollow fiber unit 110 includes a filament 111 made of a magnetic material and a transparent hollow fiber 112. Although not limited to this in FIG. 1 and FIG. 2, the filament colored black is illustrated as the filament 111 which consists of magnetic bodies. Since the filament is black, it is observed as a display material inside the transparent hollow fiber unit in the paper, and thus an overt function is exhibited. There is also a unique effect that the black filament moves by bringing the magnet closer. Further, since the filament is a magnetic material, it functions as a recording material detected by a magnetic sensor or the like and exhibits a covert function.

Next, the material of the anti-counterfeit paper according to the present invention will be described.
As the material of the filament 111 made of a magnetic material, it can be used as the relative permeability is in the range of 10 to 10 ^5.
Here, the magnetic permeability (μ) is a proportionality constant μ when the relationship between the magnetic field (B) and the magnetic flux density (H) is expressed by B = μH, and the ratio of μ / μ0 to the vacuum magnetic permeability μ0. It is called relative permeability (μs). In general, the higher the responsiveness to the magnet, the smaller the relative permeability at the beginning (low magnetic flux density), but the relative permeability tends to increase rapidly as the magnetic flux density increases. In the present invention, the relative magnetic permeability is used as an index for selecting a magnetic material that can practically respond to a magnet.
As a result, it was found that a material having a relative permeability in the range of 10 to 10 ⁵ can be suitably used. When the relative magnetic permeability is less than 10, the responsiveness to the magnet is weak, so that the filament as the display material does not move sufficiently. On the other hand, generally, the greater the relative permeability, the greater the variation in magnetic properties due to deformation during processing. Therefore, when considering the authenticity determination by device detection, a material having a relative permeability exceeding 10 ⁵ is not preferable because the fluctuation of magnetism is too large. As the material relative magnetic permeability is in the range of 10 to 10 ^5, it is possible to use stainless steel such as SUS in the JIS standard, it is not limited thereto. In addition, materials should be appropriately selected from metals exhibiting ferromagnetism such as iron, cobalt, nickel such as magnetite and ferrite, or alloys or compounds (such as oxides) containing these elements. Can do.

The filament material made of the magnetic material may have an outer diameter of about 10 μm to 300 μm, preferably 30 μm to 300 μm. If it is less than 10 μm, it may not be observed by human eyes when used as an overt. On the other hand, if it exceeds 300 μm, the movement in the hollow fiber is not smooth, and there is a possibility that it will not move even if the magnet is brought closer.

  A filament having a length in the range of 1 mm to 30 mm can be suitably used. When the length of the filament is shorter than 1 mm, it is difficult to visually recognize especially when the diameter of the filament is small. On the other hand, if the filament length exceeds 30 mm, the filament may not be able to move smoothly through the transparent hollow fiber, particularly when the transparent hollow fiber is bent.

The filament may be a monofilament made of a single wire or a multifilament-shaped stranded wire obtained by twisting a plurality of wires. In either case, it may be used after being coated with a resin or the like. In particular, in the case of a stranded wire, since the resin can be encapsulated inside the filament, it can be easily combined, and as a result, it is advantageous for coloring and adjusting the specific gravity. Moreover, visibility can be improved by containing a coloring material and a fluorescent material through resin.

In addition, the transparent hollow fibers contain not only filaments made of magnetic material but also inorganic particles, organic polymer particles, inorganic / organic composite particles, etc., in order to increase contrast and display other colors. Also good. For example, the inorganic particles include, but are not limited to, titanium oxide, titanium hydroxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white. , Cadmium yellow, cadmium red, cadmium orange, titanium yellow, bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, aluminum powder and the like. Examples of the organic polymer particles include urethane, nylon, fluorine, silicone, melamine, phenol, styrene, styrene-acrylic, urethane-acrylic and the like. Moreover, the hollow particle which consists of a styrene-acrylic system is also mentioned. These particles may be colored with pigments or dyes. In particular, the overt function can be improved by adding a fluorescent dye.

As a material of the transparent hollow fiber 112, it is sufficient that the material has transparency enough to recognize a display material or the like. Specific materials that can be selected from the viewpoint of transparency include polyester resins, polyolefin resins, acrylic resins, urethane resins, polystyrene resins, acrylonitrile-butadiene-styrene copolymers (ABS resins), fluorine Examples thereof include a resin based on resin (eg, tetrafluoroethylene resin), a silicone resin, a nylon resin, and a vinyl chloride resin.

Among the materials of the transparent hollow fiber 112, celluloid, acetyl cellulose, and the like are preferably used. The material from now on has a strong affinity with paper. When a transparent hollow fiber unit made of celluloid, acetylcellulose, or the like is to be peeled off from the anti-counterfeit paper of the present invention, the transparent hollow fiber unit does not peel off from the paper well, but rather the unit itself is broken. Therefore, it is difficult to reuse the transparent hollow fiber unit for counterfeiting.

The transparent hollow fiber 112 having an inner diameter of about 40 μm to 490 μm and an outer diameter of about 50 μm to 500 μm can be used. If the inner diameter is less than 40 μm, it is difficult to feed the filament. On the other hand, when the outer diameter exceeds 500 μm, it becomes too thick compared to the thickness of general paper, which is not preferable in appearance but also easily peeled from the paper. Further, the hollow fiber is not too thin and is not brittle. Although it depends on the material, generally a thickness of 10 μm or more is preferable.

Next, the pulp fiber that is the raw material of the forgery preventing paper 100 of the present invention will be described. Pulp fibers include plant fibers made of wood pulp such as conifers and hardwoods, plant fibers made of non-wood pulp such as rice, esparto, bagasse, hemp, flax, kenaf, cannabis, or polyethylene terephthalate, polypropylene, polyacrylate, poly Synthetic fibers made from plastic such as vinyl chloride are used.

The paper used in the present invention is made by beating the pulp fibers as raw materials in water, making them tangled and then dehydrating and drying them. At this time, the interfiber strength is obtained by hydrogen bonding between the hydroxyl groups of cellulose, which is the main component of the paper. In addition, the fillers used for paper include clay, talc, calcium carbonate, and titanium dioxide, and the sizing agents include rosin, alkyl ketene dimer, stearic anhydride, alkenyl succinic anhydride, and wax. Examples of the reinforcing agent include modified starch, polyvinyl alcohol, polyacrylamide, polyamide polyamine epichlorohydrin resin, urea-formaldehyde, melamine-formaldehyde, polyethyleneimine, and the like. Make paper.

In addition, in the case of paper mixed with synthetic fibers other than plant fibers, for example, a binder is often required because there is no bonding force such as hydrogen bonding between the synthetic fibers. The amount of the adhering agent is preferably determined as appropriate so as not to reduce the strength of the paper.

Next, the manufacturing method of the forgery prevention paper of this invention is demonstrated.
A transparent hollow fiber can be manufactured as follows, for example. A polymer fiber having a substantially concentric two-layer structure is produced by a melt spinning method or the like, and the fiber is drawn to obtain a fiber having an outer diameter of about 50 to 500 μm. At this time, the inner layer is a resin that is dissolved by washing with water or an organic solvent after molding. By removing the resin in the inner layer by dissolution, a transparent hollow fiber can be obtained. Alternatively, if a fluid is introduced in advance instead of the soluble resin in the inner layer, it is not necessary to remove the resin later, and the transparent hollow fiber can be more easily produced. As the fluid to be introduced at this time, a gas such as air or nitrogen gas is preferable.

Next, a filament to be included is prepared in advance and fed into the transparent hollow fiber. Specifically, a large number of transparent hollow fibers are bundled and placed in a chamber, the chamber is evacuated, and then the filament is introduced into the chamber, whereby the filament can be fed into the hollow fiber. .

The end of the transparent hollow fiber may be sealed as necessary so that the enclosed filament does not go out or foreign matter is not mixed inside. For sealing, there are a method using an adhesive, a method in which a transparent hollow fiber material is dissolved by heating, a method in which the transparent hollow fiber is cut at the same time as cutting with a laser beam, and the like. As the adhesive, generally known adhesives such as water-based adhesives, emulsion-based adhesives, and solvent-based adhesives are appropriately used, but solvent-based adhesives are preferably used. For example, adhesives such as urethane, epoxy, polyester, alkyd, amide, and acrylic can be used. Further, a special adhesive such as a UV curable resin may be used.

In the method of dissolving the hollow fiber material by heating, a heat cutter in which the cutter blade is heated is generally used. In the method using laser light, a carbon dioxide laser (CO ₂ laser), an yttrium-aluminum-garnet crystal laser (YAG laser), a semiconductor laser, or the like can be used.

The paper making method of the anti-counterfeit paper mixed with the transparent hollow fiber unit may be a method used for the production of ordinary plant fiber paper. The raw material concentration is 0.01 to 5%, preferably 0.02 to 2% water. It is made by thoroughly kneading fibers sufficiently swollen with dilute raw materials, pouring them through a sled / mesh wire, etc., squeezing them, and evaporating the water by heating. After paper making, if necessary, it may be subjected to processing such as clear coating, laminating, and paper making.

The transparent hollow fiber unit of the present invention can also be used as thread type anti-counterfeit paper.
The transparent hollow fiber unit can be used as a thread even if it remains in the form of a thread. However, even if the fibers are bundled and processed into a sheet using an apparatus as shown in FIG. 4 disclosed in JP-A-2005-250066. Good. As the adhesive between the fiber units, generally known adhesives such as water-based adhesives, emulsion-based adhesives, and solvent-based adhesives are appropriately used, but solvent-based adhesives are preferably used. For example, adhesives such as urethane, epoxy, polyester, alkyd, amide, and acrylic can be used.

The paper making method of the anti-counterfeit paper in which the transparent hollow fiber unit is inserted as a thread may be a method used for manufacturing ordinary threaded paper. That is, a forgery-preventing paper is obtained by inserting a thread and joining the thread and the paper in the moisture and drying process at the time of making at least the final paper making of the multilayer paper machine.
Hereinafter, since a window opening type excellent in overt is preferable from the viewpoint of overt, a method for manufacturing a window opening type thread paper will be described, but the thread buried type is not excluded from the present invention.

As a method of manufacturing a window-open threaded paper, a method of manufacturing a paper suspension on a wire by burying a belt mechanism having a groove through which a thread is inserted at the tip of a convex portion of a guide having a concave and convex portion (patent) (Refer to Document 5) or using a net processed into a concavo-convex shape for the upper net of a circular paper machine and inserting the thread while making contact with the concavo-convex portion of the net surface (Patent Document) 6), a method of forming a paper layer having a perforated hole by sticking a tape on the surface of a circular cylinder of a circular paper machine at regular intervals (see Patent Document 7), A method in which a compressed air nozzle is built in a rotating drum on a wire of a machine, and slurry on a thread previously inserted in a web is blown intermittently with compressed air to expose the thread on the surface of the paper (see Patent Document 8) Has been proposed. It may be in any way, including the above-described method as a method for producing a thread containing paper open window

Japanese Patent Publication No. 5-85680 U.S. Pat. No. 4,462,866 JP-A-10-292293 JP-A-6-272200

The same equipment and method as the conventional paper can be used for printing on the anti-counterfeit paper subjected to the anti-counterfeit measures of the present invention. That is, characters and designs can be printed by various printing methods such as offset printing, screen printing, gravure printing, letterpress printing, and intaglio printing.

The anti-counterfeit paper according to the present invention is to determine authenticity by visual observation without using a special instrument due to the presence of the magnetic filament contained in the transparent hollow fiber unit. Also, authenticity is determined using a magnetic sensor based on the presence of the magnetic filament contained in the transparent hollow fiber unit. That is, both overt and covert are compatible.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

Example 1
<Preparation of filament made of magnetic material>
300 stainless steel filaments of JIS standard SUS301 having a diameter of 80 μm and a length of 3 mm subjected to cold working were prepared. The relative permeability of this stainless steel filament was 14.0. Note that the surface of the filament was colored with magic ink in order to improve the visibility when it was woven into paper.

<Preparation of transparent hollow fiber>
Using a melt extrusion molding machine, the polyester resin was extruded from the nozzles around the center while flowing the inclusion substance from the gas discharge hole at the center of the nozzle. The extruder temperature was 250 ° C. The extrusion rate of the molten polyester resin was 0.20 kg / hr. The molten fiber at the exit of the extruder was stretched to obtain a transparent hollow fiber having an outer diameter of 120 μm and an inner diameter of 100 μm.

<Production of transparent hollow fiber unit>
Subsequently, 100 transparent hollow fibers are bundled and placed in a chamber, the chamber is evacuated, and a liquid in which the filaments are dispersed in ethanol is introduced into the chamber, thereby filling the transparent hollow fibers with the dispersion. did.
The transparent hollow fiber enclosing the dispersion was sufficiently dried to remove ethanol, and then cut with a cutter heated to a cut length of approximately 15 mm. When the cut surface portion of the transparent hollow fiber was melted and crushed while being cut, the end portion was sealed, and a transparent hollow fiber unit having a magnetic filament inside could be formed.

<Preparation of anti-counterfeit paper>
As the raw material of the paper, a paper strength enhancer (trade name: AF-255, manufactured by Arakawa Chemical Industries) is added to 0.1% of the dry pulp to conifer kraft pulp (beating degree: 430 cc CSF) having a concentration of 0.5% in water. % Added paper stock was used. The paper was mixed with the transparent hollow fiber unit containing the magnetic powder and titanium oxide, and paper with a basis weight of 70 g / m ² was made with a handrail machine for experiments. Drying was performed at 90 ° C. using a rotary dryer. The transparent hollow fiber unit was uniformly dispersed on the front surface of the paper, and a forgery-preventing paper in which the transparent hollow fiber unit was not easily peeled was obtained. The thickness of the anti-counterfeit paper was 135 μm.

<Effect of forgery prevention>
In the portion where the magnet was applied, the movement of the filament could be visually observed in the transparent hollow fiber unit, thus confirming the effect of overt.
On the other hand, when the head of the magnetic sensor (trade name: ST008 type, manufactured by Nippon CDR) is slid to the left and right while touching the surface of the anti-counterfeit paper, the magnetic sensor becomes a magnetic filament when the head approaches the transparent hollow fiber unit. A beeping sound was generated and the effect of covert was confirmed.

Example 2
The anti-counterfeit paper is the same as in Example 1 except that the filament made of a magnetic material is changed to a stainless steel filament of JIS standard SUS302 having a diameter of 30 μm, a length of 1 mm, and a relative permeability of 10 which has been cold-worked. Produced.

<Effect of forgery prevention>
In the portion where the magnet was applied, the movement of the filament could be visually observed in the transparent hollow fiber unit, thus confirming the effect of overt.
In addition, when the head of the magnetic sensor (trade name: ST008 type, manufactured by Nippon CDR) is slid to the left and right while touching the surface of the anti-counterfeit paper, the magnetic sensor becomes a magnetic filament when the head approaches the transparent hollow fiber unit. A beeping sound was generated and the effect of covert was confirmed.

Example 3
Anti-counterfeiting paper exactly as in Example 1, except that the filament made of a magnetic material is changed to a twisted filament made by twisting seven stainless steel wires of JIS standard SUS301 with a diameter of 15 μm subjected to cold working. Was made. The twisted wire had a diameter of 50 μm, a length of 3 mm, and a relative permeability of 14.0.

<Effect of forgery prevention>
In the portion where the magnet was applied, the movement of the filament could be visually observed in the transparent hollow fiber unit, thus confirming the effect of overt.
In addition, when the head of the magnetic sensor (trade name: ST008 type, manufactured by Nippon CDR) is slid to the left and right while touching the surface of the anti-counterfeit paper, the magnetic sensor becomes a magnetic filament when the head approaches the transparent hollow fiber unit. A beeping sound was generated and the effect of covert was confirmed.

Example 4
<Preparation of filament made of magnetic material>
3000 permalloy filaments having a diameter of 300 μm and a length of 30 mm, which are standardized as an iron-nickel alloy according to JIS-C-2531, were prepared. The relative permeability of this filament was 8.0 × 10 ⁴ . Note that the surface of the filament was colored with magic ink in order to improve the visibility when it was woven into paper.

<Production of transparent hollow fiber unit>
Except that a polypropylene resin was used in place of the polyester resin, extrusion molding was performed in the same manner as in Example 1, and the molten fiber at the exit of the extruder was stretched to obtain a transparent hollow fiber having an outer diameter of 500 μm and an inner diameter of 400 μm.
Subsequently, 1000 transparent hollow fibers are bundled and placed in a chamber, the chamber is evacuated, and a liquid in which the filaments are dispersed in ethanol is introduced into the chamber, thereby filling the transparent hollow fibers with the dispersion. did.

<Preparation of anti-counterfeit paper>
As the raw material of the paper, a paper strength enhancer (trade name: AF-255, manufactured by Arakawa Chemical Industries) is added to 0.1% of the dry pulp to conifer kraft pulp (beating degree: 430 cc CSF) having a concentration of 0.5% in water. % Added paper stock was used.
On the other hand, in a circular paper machine equipped with two tank bats, a tape of 1 cm x 1 cm is attached in advance at the intervals of 1 cm on the same circumferential surface of the first cylinder cylinder, and the mesh is closed. The first paper layer (air-dried rice tsubo 70 g / m ² ) was formed with a paper layer having 1 cm × 1 cm holes every 1 cm. The second round tank cylinder was not crafted, and a plain second paper layer (air-dried rice tsubo 140 g / m ² ) was formed. Also, a thread unwinding device is installed between the first and second cylinders, and the second paper layer and the aluminum vapor deposition surface side are located at a position where the thread made of the transparent hollow fiber unit overlaps the hole of the first paper layer. It was inserted in the direction of contact. As the raw material of the paper, the above-mentioned stock was used, dried with a Yankee dryer in contact with the first paper layer, and then a cylinder dryer, and then machine calendared. Through the above steps, a window-open type threaded anti-counterfeit paper having a transparent hollow fiber unit as a thread was obtained. The thickness of the anti-counterfeit paper was 400 μm.

<Effect of forgery prevention>
In the transparent hollow fiber unit on the surface of the paper as a thread, the movement of the filament could be visually observed in the transparent hollow fiber unit at the portion where the magnet was applied, so the effect of overt was confirmed.
In addition, when the head of the magnetic sensor (trade name: ST008 type, manufactured by Nippon CDR) is slid to the left and right while touching the surface of the anti-counterfeit paper, the magnetic sensor becomes a magnetic filament when the head approaches the transparent hollow fiber unit. A beeping sound was generated and the effect of covert was confirmed.

Comparative Example 1
Except for changing the filament made of a magnetic material to a stainless steel filament of JIS standard SUS316 having a diameter of 20 μm, a length of 0.8 mm, and a relative permeability of 1.02, which has been cold-worked, the same as in Example 1. An anti-counterfeit paper was prepared.

<Effect of forgery prevention>
Even at the portion where the magnet was applied, the movement of the filament in the transparent hollow fiber unit was not visible.
Also, the head of the magnetic sensor (trade name: ST008 type, manufactured by Nippon CDR) was slid to the left and right while touching the surface of the anti-counterfeit paper, and the head was brought close to the transparent hollow fiber unit, but there was no reaction from the magnetic sensor. It was.

The decisive factor in anti-counterfeiting is to give up counterfeiters by adopting as many combinations of anti-counterfeiting measures as possible. The present invention is a combination of a novel anti-counterfeiting means of moving a magnetic filament and an existing anti-counterfeiting means of responding to a magnetic sensor, and has an anti-counterfeiting effect in that a plurality of anti-counterfeiting measures are taken. High, and therefore industrial value is high.

Conceptual diagram of anti-counterfeit paper of the present invention Sectional view of the anti-counterfeit paper of the present invention Conceptual diagram of anti-counterfeit paper mixed with transparent hollow fiber unit Cross section of anti-counterfeit paper mixed with transparent hollow fiber unit

Explanation of symbols

100: anti-counterfeit paper 110 of the present invention: transparent hollow fiber unit 110a of the present invention: state in which the transparent hollow fiber unit appears on the paper surface 110b: state in which the transparent hollow fiber unit is inside the paper layer 111: magnetism of the present invention Filament 112 made of body: transparent hollow fiber 300 of the present invention: anti-counterfeit paper 310 containing transparent hollow fiber unit: transparent hollow fiber unit 310a: state where transparent hollow fiber unit appears on paper surface 310b: transparent hollow fiber unit Is in the paper layer 311: Magnetic powder 312: Transparent hollow fiber

Claims (6)

  An anti-counterfeit paper characterized in that at least one transparent hollow fiber enclosing a filament made of a magnetic material is mixed in paper.   An anti-counterfeit paper, wherein the transparent hollow fiber is inserted into paper as a thread.   The anti-counterfeit paper according to claim 1 or 2, wherein the filament has a diameter in a range of 10 µm to 300 µm.   The forgery prevention paper according to any one of claims 1 to 3, wherein a length of the filament is in a range of 1 mm to 30 mm. Relative permeability of the filaments, anti-falsification paper according to claim 1 in the range of 10 to 10 ^5.   The anti-counterfeit paper according to any one of claims 1 to 5, wherein the filament is made of a stranded wire.

Images