JP2001032192A - Thread for preventing forgery and paper for prevention of forgery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain thread for prevention of forgery having high forgery- preventing effect and paper for prevention of forgery using the same thread. SOLUTION: This thread is used by making the thread into paper for prevention of forgery and the thread is obtained by providing a protruded part 13 formed by printing ink on a substrate 11 composed of a resin film and further forming a ferromagnetic thin film layer 15 having 0.5-50 oersted coercive force and 0.75-1.0 squareness ratio thereon. Such thread may be constituted by combining a part having a protruded part with a part not having the protruded part so as to give a definite signal accompanied by the output difference of signal and a light-reflecting layer can be formed between the ferromagnetic thin film layer and the protruded part and the substrate. This thread for prevention of forgery is obtained by making thread for prevention of forgery into a base paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forgery prevention thread and a forgery prevention paper using the same. Specifically, a convex portion is provided with printing ink so that a pattern that is partially convex is formed on the surface of the base resin film, and the ferromagnetic material thin film layer applied on the resin film or the convex portion is formed. The present invention further relates to a forgery prevention thread and a forgery prevention paper using the same. Such anti-counterfeit paper can be used for various security media such as gift certificates, gift certificates, certificates, tickets, voting tickets, tickets, labels and the like.

[0002]

2. Description of the Related Art As a countermeasure for preventing forgery of various security media, there is a method of forming various threads on paper. Since the forgery prevention means using such a thread is provided at the stage of manufacturing the paper, it is difficult to forge by a method such as color copying, taking in a scanner, and plate making printing.
However, there is a case where counterfeit paper in which a counterfeit thread imitating a genuine thread is produced is circulated, and a simple magnetic thread or glitter thread alone may not be enough to determine authenticity.

[0003] On the other hand, a structure in which a general magnetic recording material is combined with a thread cannot easily be said to be a highly falsified anti-counterfeit structure because magnetic recording information can be easily falsified. Therefore, as a data recording carrier having a more advanced anti-counterfeit structure, a structure in which a convex portion and a magnetic film are combined is disclosed in JP-A-10-64051.
In Japanese Patent Laid-Open Publication No. H11-264, a magnetic-patterned magnetic plate or the like is proposed. Therefore, the present invention is intended to further improve the forgery prevention effect by further improving such a magnetic plate and applying it to a forgery prevention thread or a forgery prevention paper using the same.

[0004]

Means for Solving the Problems A first aspect of the present invention for solving the above-mentioned problems is a thread for use in forging into anti-counterfeit paper, which is formed on a substrate made of a resin film. A convex portion made of printing ink is provided, and the coercive force applied on the resin film substrate and the convex portion is 0.5
５０50 Oersted and squareness ratio 0.75 to 1.0
Wherein the anti-counterfeiting thread further comprises a ferromagnetic material thin film layer. Because of such a forgery prevention thread, forgery and falsification are difficult.

[0005] Such a forgery prevention thread can be configured such that a portion having a convex portion and a portion having no convex portion are combined so as to give a constant signal according to a signal output difference. A light reflection layer may be provided between the projection and the base. Further, if an adhesive layer is provided on the surface opposite to the surface on which the convex portion of the thread is formed or on the ferromagnetic material thin film layer, the adhesion of the forgery prevention paper to the base paper can be strengthened.

A second aspect of the present invention for solving the above-mentioned problems is a forgery prevention paper provided with the above-described forgery prevention thread formed in a base paper. An anti-counterfeit paper comprising an exposed part intermittently exposed and a covering part intermittently covering the thread between the exposed parts. Because of such anti-counterfeit paper, forgery and falsification are difficult. Such forgery prevention paper may be provided with a plurality of rows of exposed portions and covering portions, and may be formed by incorporating a plurality of forgery prevention threads. In this way, forgery and falsification are more difficult.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a smooth convex portion having a constant thickness is provided by a printing ink on a substrate made of a resin film, and a ferromagnetic material thin film is formed on the surface by a vapor phase method such as sputtering. The present invention relates to a forgery prevention thread and a forgery prevention paper using the same. Since the ferromagnetic material thin film used in the present invention is basically a thin film formed by vapor deposition such as evaporation or sputtering, the thin film has a coercive force of 0.5 to 50 Oe and a squareness of 0. In order to obtain a value such as 0.75 to 1.0, the surface of the base material and the surface of the convex portion must be flat.

When a protrusion made of printing ink is formed on a base material made of a resin film, and a ferromagnetic material thin film is formed thereon, the shape of the protrusion is made to follow the protrusion formed by the printing ink. Then, the magnetic material thin film is formed. When the convex portion has a constant thickness from the surface of the base material, and when the surface is made smooth, when the output is measured with a magnetic head, it may be from either the front or back surface of the base material. If the signal output ratio is within a certain distance from the magnetic head, the signal output ratio is detected as a difference in output generated in the magnetic head because the distance from the magnetic head is different between the portion having the convex portion and the portion not having the convex portion. The present invention intends to apply a certain signal to a thread by utilizing such characteristics. Note that the thickness of the ferromagnetic material thin film is substantially the same under ordinary conditions whether or not there is a projection made of printing ink. When such a ferromagnetic material thin film is measured from, for example, the back surface of the substrate (the surface on which the ferromagnetic material thin film is not provided), the output is large where there is no convex portion, and the output is large where there is a convex portion made of printing ink. Become smaller. If there is any layer on the ferromagnetic material thin film that allows the magnetic head to move in parallel (for example, a layer formed by applying a filling material only to a concave portion where a convex portion is not formed by a wiping coating method), a ferromagnetic material The detection may be performed by placing a magnetic head on the surface on which the thin film is formed. In this case, the output is reversed.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of a forgery prevention thread of the present invention. In the case of this embodiment, the forgery prevention thread 10 has a protrusion 13 made of printing ink on a base material 11 made of a resin film,
On the surface of the resin film substrate and the surface of the convex portion, a ferromagnetic material thin film layer 15 is provided so as to follow the convex portion 13. When measured from the back surface of the base material as described above, the convex portion 13 is read by a magnetic head giving a small output magnetic characteristic, and a smooth portion without printing ink is given a large output magnetic characteristic. In a preferred embodiment of the present invention, as will be described later,
It consists of a combination of existing and non-existent parts,
The object of the present invention is to provide unique identification information to the read magnetic characteristics from the unique pattern configuration.

An adhesive layer 16a is provided on a surface of the substrate 11 opposite to the surface on which the projections 13 are formed (hereinafter, also referred to as a "back surface"), and an upper surface of the ferromagnetic material thin film layer 14 (hereinafter, referred to as a "front surface"). ) May be provided with an adhesive layer. These adhesive layers have an effect of increasing the adhesive strength with the paper when the thread is laid on the forgery prevention paper.

Hereinafter, each component of the forgery prevention thread will be described in more detail. As the base material 11, a water-resistant and heat-resistant resin film can be used. Generally, other polyester resin films including a polyethylene terephthalate (PET) resin film,
Examples thereof include a polyamide resin film, a polyimide resin film, a polycarbonate resin film, a polystyrene resin film, a polypropylene resin film, a polysulfone resin film, a polyphenylene sulfide resin film, and a cellulose resin film. The thickness is 1
A thickness of about 300 μm, preferably 5 to 50 μm can be recommended. In the case where the output ratio is measured from the back surface of the base material, and when the convex portion is formed with a height of about 10 μm or less,
In order to clearly detect the relative output ratio, it is preferable that the thickness of the base material is about 5 to 20 μm.

The printing ink for forming the printing projections is as follows:
It is preferable that the projection is a flat surface. It is preferable to include a granular material in order to increase the thickness of the convex portion. Fine particles having a particle size of about 1 μm or less are combined with a binder (resin or the like) and dissolved in a solvent to form an ink. The ink does not need to be colored as long as it can make the substrate surface convex. In the present invention, the projections made of the printing ink may be formed such that certain uneven stripes are arranged in a certain direction. However, even in the case of the stripe shape, the diffraction grating effect does not occur because of the coarse pitch provided by printing. The surface of the projection 13 is required to be smooth,
The thickness Δh of the convex portion from the substrate surface may be any value that gives a significant difference to the detected output value. Usually 1μ
It is sufficient that the thickness is about m to 50 μm, and it can be made sufficiently thicker than the thickness of the ferromagnetic material thin film layer 15. However, if the thickness of the ink layer becomes large, cracks, cracks in the magnetic film, etc. may occur, which may affect the measurement.
It is considered that about 0 μm is the limit. On the other hand, if it is thinner than 1 μm, a sufficient output signal difference cannot be obtained. More preferably, 5 to 2
It is about 0 μm. It is preferable that the signal output ratio (output ratio of the convex portion / output ratio of the flat portion) when measured from the back surface of the base material at this thickness is about 0.1 to 0.5. 0.
If the value is 1 or less, the detection signal becomes too weak, and if the value is 0.5 or more, a significant difference from the flat portion may not be sensed. Such printing ink can be printed by intaglio printing such as silk screen printing or gravure.

Next, the ferromagnetic material thin film layer 15 may be crystalline or amorphous, and may be made of iron (Fe),
A magnetic material composed of one or a combination of two or more of cobalt (Co) and nickel (Ni) is used as a main component, and boron (B), carbon (C), magnesium (Mg), aluminum ( Al), silicon (Si), phosphorus (P), sulfur (S), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), copper (C
u), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), palladium (Pd), silver (Ag), indium (In),
Tin (Sn), tantalum (Ta), tungsten (W),
It is composed of an additive of several kinds of metal or nonmetal elements selected from iridium (Ir), platinum (Pt), gold (Au), and lead (Pb).

The ferromagnetic material thin film layer is formed by sputtering, vapor deposition, ion plating, etc., using a material composed of an alloy composed of iron, cobalt, nickel as a main component and an additive element or a mixture thereof as a target material or a vapor deposition source. Formed by means using a vacuum process. The ferromagnetic material is represented by a material based on cobalt Co-zirconium Zr or iron Fe-silicon Si. The thickness of the ferromagnetic material thin film layer is suitably from 500 to 5000 °. The reason that the lower limit value of the layer is 500 ° or less is because the thickness of the magnetic layer is thinner, the saturation magnetic flux is reduced along with the decrease in the absolute amount of the magnetic body, and the magnetic signal is reduced. This is because the magnetic material needs to have a thickness of 500 ° or more in order to obtain a magnetic signal to be used. Also,
The reason why the upper limit is 5000 ° is to make a clear distinction from a magnetic film (usually 1 μm or more in thickness) produced by another method, and it is preferable to avoid making it thicker. Further, when the thickness is more than this, the characteristics of the thread deteriorate due to curl or the like due to the internal stress of the film, and wrinkles and cracks may occur. From the viewpoint of the productivity of the ferromagnetic material thin film layer and the stability of the magnetic signal, the preferable thickness of the layer is 1500 to 3000 °.
(0.15 to 0.3 μm).

Such a ferromagnetic thin film layer exhibits unique characteristics in terms of Hc (coercive force) and Bm (saturation magnetic flux density). Is the nonlinear BH
Since it has characteristics (hysteresis curve), it can be clearly distinguished from general magnetic materials. The ferromagnetic thin film layer used in the present invention has an Hc (coercive force) of 0.5 to 50O.
e, Rsq (square ratio) is preferably 0.75 to 1.0. FIG. 2 shows a hysteresis curve of the ferromagnetic material thin film layer. On the smooth and uneven surface of the base material, the ferromagnetic material thin film layer 15 has a small coercive force Hc as shown in FIG.
In addition, a BH hysteresis curve with a high squareness ratio (0.8 to 1.0) is obtained. The squareness ratio Rsq is represented by Rsq = Br (residual magnetic flux density) / Bm (saturated magnetic flux density).

A non-magnetic metal film can be provided as a light reflecting layer between the ferromagnetic material thin film layer 15 and the projection 13 or the substrate 11. In this case, the glossy color of the nonmagnetic metal is observed from the outside as reflected light without being affected by the color of the ferromagnetic thin film, and the appearance is different from that of a general glittering thread. No anti-counterfeiting thread is given. For such a light reflecting layer, a reflective non-magnetic metal material is used, and gold, silver, aluminum, chromium, or the like is used. Generally, aluminum is preferably adopted from the viewpoints of cost and technical problems, and its thickness is set to 100 mm or more.
It can be formed to a thickness of about 2000 mm, but preferably 20
The thickness is about 0 ° to 1000 °. This layer functions not only as a reflective layer but also as a smoothing layer for filling fine irregularities on the surface of the resin film or the surface of the printing ink. In order to read the magnetic properties of the thread from the exposed portion of the base paper with a magnetic head, a metal film as a light reflection layer may be provided on the back surface of the thread if the back side of the thread is laid out so as to appear on the exposed portion. good.

FIG. 3 is a diagram showing an example of a convex portion of the forgery prevention thread. It shows a pattern of a configuration combined to give specific magnetic properties as described above,
The convex portion 13 and the portion 13n having no convex portion have different read magnetic characteristics in the scanning direction of the magnetic head or the length direction of the sled. In FIG. 3 (A), “existing” portions 13 and “absent” portions 13n of the convex portions are formed alternately and repeatedly in the length direction of the thread. As described above, when measured from the back surface of the base material, the magnetic signal is weakened or disappears in a portion having a convex portion. Therefore, the “present” portion of the convex portion is “0”, and the “absent” portion is “1”. Then, a repetition signal of 0, 1, 0, 1 is obtained. In FIG. 3 (B), the “existing” portion 13 and the “absent” portion 13n of the convex portion are 2 mm in the length direction of the thread.
Each is repeatedly formed in the order of one piece. If the “existing” portion of the projection is “0” and the “absent” portion is “1”, a repeated signal of 0, 0, 1, 0, 0, 1 can be obtained.

The adhesive layer 16a is formed of a thread 1 for preventing forgery.
This is to increase the adhesive strength between the paper and the paper when the paper No. 0 is formed on the paper. An adhesive layer made of a water-soluble binder or the like having a heat dissolution temperature of 60 to 80 ° C. is provided on the back surface of the base material 11. be able to. Alternatively, the adhesive layer may be provided on the upper surface (front surface) of the ferromagnetic material layer. Specifically, an adhesive made of water-soluble starch, casein, carboxymethylcellulose, carboxyethylcellulose, or the like can be used. Alternatively, the adhesive layer may be a hot melt adhesive having a heat melting temperature of 60 to 80 ° C. The coating thickness may be within a few μm.

Next, the anti-counterfeit paper of the present invention will be described. The anti-counterfeit paper in which the thread is exposed in the window is a conventional type of paper in which a glittering thread or a magnetic thread is formed on a base paper, for example, and the base paper is a glittering thread. And a covering portion that intermittently exposes a brilliant thread between the exposed portions. The anti-counterfeit paper of this configuration is provided with a small convex portion having the same width as or wider than the thread on one papermaking net of the multi-cylinder paper machine, and the thread is placed on the convex portion. It can be manufactured by supplying stock liquid. In other words, in this case, at the position where there is no convex portion, the thread is sandwiched by the stock liquid, so that the covering portion is formed, and at the position of the convex portion, the thread is exposed from the lower surface side of the stock liquid, so that the exposed portion is formed. It is formed.

In the threaded paper with a window as described above, since the glittering thread and the like are intermittently exposed in the exposed portion, the forgery can be prevented because the metallic color is not reproduced even when copied. Also, there is no need to check the edge of the paper to see if it is counterfeit,
Moreover, it is possible to prevent the glittering thread or the like from peeling off from the base paper.

FIG. 4 is a view showing a first embodiment of the forgery prevention paper of the present invention. FIG. 4A is a plan view of FIG.
FIG. 4B shows a cross section taken along line AA of FIG. As shown in FIG. 4, the first forgery prevention paper 20 of the present invention
In the embodiment of the present invention, a single thread 10 is formed into the base paper 21, and the base paper 21 includes a plurality of exposed portions 26 that intermittently expose the thread 10, and each of the exposed portions 26. And a covering portion 27 intermittently covering the thread 10 therebetween. The exposed portion 26 may have the same width as the thread, but the width is made wider than that so that both sides of the thread 10 serve as the watermark portions 28, so that the tolerance of the threads (blurring) generated during papermaking is absorbed by the watermark portions. be able to.

However, it is preferable that both ends of the thread 10 of the base paper 21 are formed as the covering portions 17 for any thread. This is because the exfoliation of the thread occurs when the end of the thread is exposed. The width of the thread to be used is not particularly limited by the purpose of use of the paper, but a width of about 0.2 mm to 5 mm is usually used.

FIG. 5 is a view showing a second embodiment of the forgery prevention paper of the present invention. FIG. 5A is a plan view thereof, and FIG.
FIG. 5B shows a cross section taken along line AA of FIG. As shown in FIG. 5, in the second embodiment of the forgery prevention paper of the present invention, a plurality of threads 10 are formed in the base paper 21, and the base paper 21 intermittently exposes the threads 10. And a thread 1 between each of the
0 that intermittently covers the first
This is the same as the embodiment. The second embodiment is characterized in that the exposed portion 26 and the covering portion 27 appear in the same state at the same position from the end of the sheet at the end of the thread for a plurality of threads. That is, at the position x from the paper end, the thread 10a
b is also an exposed portion, and at a position y from the end of the sheet, both the sled 10a and the sled 10b are covered portions.

However, it is preferable that both ends of the thread 10 of the base paper 21 are formed as the covering portions 27 for any thread. This is because the exfoliation of the thread occurs when the end of the thread is exposed. The width of the thread to be used is not particularly limited by the purpose of use of the paper, but a width of about 0.2 mm to 5 mm is usually used. The widths of the plurality of threads need not be the same, and the color tone, the optical characteristics, the coloring characteristics, the magnetic characteristics, and the like can be arbitrarily changed. As described above, by introducing two or more threads into the security medium, a method of simply attaching a forged thread increases the forgery cost and the process becomes complicated, thereby increasing the forgery suppression effect. .

FIG. 6 is a view showing a third embodiment of the forgery prevention paper of the present invention. FIG. 6A is a plan view of FIG.
FIG. 6B shows a cross section taken along line AA of FIG. As shown in FIG. 6, in the third embodiment of the forgery prevention paper of the present invention, a plurality of threads 10 are formed in the base paper 21, and the base paper 21 exposes the threads 10 intermittently. And a thread 1 between each of the
0 that intermittently covers the first
This is the same as the embodiment. In the third embodiment, the exposed portion 26 and the covering portion 27 are different between at least two adjacent threads of the plurality of threads at the same position from the end of the sheet at the thread end. There are features that are appearing. That is, at the position of x from the paper end, the thread 10a is an exposed portion, and the thread 10b is a covered portion. However, base paper 2
1 is the same as that of the first embodiment in that both end portions of the thread 10 are preferably configured as the covering portions 27, and the same applies to the following embodiments. In this way, when the exposed portions are provided in a so-called staggered manner, the swelling of the thread portion when the sheets are stacked can be reduced, the printing process can be facilitated, and the winding paper can be prevented from being broken during handling. can do.

Next, the production state of the anti-counterfeit paper of the present invention will be described. FIG. 7 is a diagram illustrating a state in which thread-forged anti-counterfeit paper is formed. 7 (A) is a cross section parallel to the thread, FIG. 7 (B) is a cross section taken along a line CC perpendicular to the thread in FIG. 7 (A), and FIG.
The cross section along the line is shown. As shown in the drawing, the thread-containing anti-counterfeit paper 20 is provided with protrusions 29a of a mesh portion having the same width as or wider than the thread 10 on the mesh portion 29 of the paper machine at appropriate intervals. It can be manufactured by supplying the stock liquid 22a while the thread 10 is placed on the top of the thread 29a. In other words, this way,
Since the thread 10 is sandwiched between the stock liquids 22a at the position between the protrusions 29a, the covering portion 27 is formed. At the position of the protrusion 29a, the thread 10 becomes the lowermost surface.
When the paper is peeled from the drafting net of the paper machine, the thread appears on the surface and the exposed portion 26 is formed.

When the width of the convex portion 29a of the cross net portion is the same as the width of the thread 10 as shown in FIG. 7D, the watermark portions 28 do not enter both sides of the thread 10. In the case where the width is set so as to straddle the thread, a decorative portion is provided to enhance the decorative effect, and the blur of the thread can be absorbed as described above. Also, a watermark pattern 2 around the thread
In the case where 5 is provided, a pattern-shaped convex portion may be formed on the cross net portion similarly to the convex portion 29a.

[0028]

[Ink composition]

 Binder; 100% by weight of polyvinyl chloride / urethane resin Granules: 10 parts by weight of microsilica (average particle size: 0.8 μm) (additional necessary amount of solvent)

Subsequently, a ferromagnetic material thin film layer 15 made of iron-Fe-Si-Si is formed on the projections and on the surface of the substrate having no projections by sputtering to a thickness of 0.2 μm. Filmed. In addition, after applying a polyvinyl chloride-based adhesive to a thickness of 1 μm on the back surface of the base film, using a slitter, the slitter was slit to a width of 2 mm so as to be orthogonal to the stripes of the projections. The forgery prevention thread has been completed.

As a result of measuring the magnetic characteristics of this thread from the back surface of the base material with a magnetic head, it was found that
The squareness ratio Rsq and the coercive force Hc in the smooth portion 13n having no irregularities were 0.98 and 20 Oe, respectively. Also, the convex portion 1
The squareness ratio Rsq at the portion where the number 3 is present is 0.85, and the coercive force H
c was 20 Oersteds, and magnetic properties with a high squareness ratio were obtained in both the convex portion and the other portions. The measurement was performed by VSM
(Sample vibration type magnetometer)
The same result was obtained by measurement with a BH analyzer using an AC magnetic field. The output ratio of the magnetic head with and without the convex portion was 0.4: 1.0. The other conditions were the same, and the thickness Δh of the projection was 5 μm and 20 μm.
The output ratio in the case of the comparative example with μm was 0.5:
1.0 and 0.2: 1.0.

<Formation of anti-counterfeit paper> The exposed part 26 has a pitch of 10 mm × 10 mm in width and a covering part so that two of the anti-counterfeit threads 10 produced above appear on the anti-counterfeit paper as shown in FIG. 27 is a paper machine having a paper-mesh pattern that is repeated at a pitch of 10 mm, and is made into high-quality paper of 90 kg / 46th plate. In addition, the stock of the upper part of the covering part 27 is 35 g /
m ^2, the lower part of the stock of the covering portion has adjusting the height of the convex portion of the network part paper making such that the 69 g / m ^2. When the anti-counterfeit paper 20 completed in this manner is read by the magnetic head, the “present” portion of the convex portion is “0” and the “no” portion of the convex portion is “1” in the length direction of the thread. ", 0,
A repetition signal of 1, 0, 1 was obtained.

[0032]

The anti-counterfeit thread of the present invention has a projection made of printing ink on a substrate, and a ferromagnetic thin film layer is formed on the projection and on a substrate that is not a projection. Therefore, a unique magnetic property can be given, and a forgery prevention effect that cannot be obtained with a normal magnetic thread or a glittering thread can be obtained. Further, since the anti-counterfeit paper of the present invention has such anti-counterfeit thread incorporated in the base paper, it is difficult to duplicate the anti-counterfeit thread and the reliability of gift certificates and other securities can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a forgery prevention thread of the present invention.

FIG. 2 shows a hysteresis curve of a ferromagnetic material thin film layer.

FIG. 3 is a diagram illustrating an example of a convex portion of a forgery prevention thread.

FIG. 4 is a view showing a first embodiment of the forgery prevention paper of the present invention.

FIG. 5 is a view showing a second embodiment of the forgery prevention paper of the present invention.

FIG. 6 is a diagram showing a third embodiment of the forgery prevention paper of the present invention.

FIG. 7 is a view showing a state in which thread-containing forgery prevention paper is made.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Forgery prevention thread 11 Base material 13 Convex part 15 Ferromagnetic material thin film layer 16a Adhesive layer 20 Forgery prevention paper 21 Base paper 22a Stock liquid 26 Exposure part 27 Coating part 28 Watermark part 29 Plow net part 29a Plow net part Convex part 30 read head

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Daisaku Hanane Inventor 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 2C005 HA01 HB11 HB13 HB20 JB28 KA15 KA37 KA48 LB18 2H113 AA03 BA03 BB08 BC11 CA39 DA15 DA57 DA62 EA01 FA09 4L055 AG03 AG47 AH37 AJ03 AJ04 AJ10 EA34 GA40 GA45 5E049 AA01 AA04 AA07 AA09 BA11 BA30

Claims (7)

[Claims] Claims: 1. A thread for use by forging into anti-counterfeit paper, wherein a convex portion made of printing ink is provided on a substrate made of a resin film, and the convex portion is provided on the resin film substrate and the convex portion. A forgery prevention thread further comprising a ferromagnetic material thin film layer having a coercive force of 0.5 to 50 Oe and a squareness ratio of 0.75 to 1.0. 2. The forgery prevention thread according to claim 1, wherein a portion having a convex portion and a portion having no convex portion are combined so as to give a constant signal according to a signal output difference. 3. The anti-counterfeit thread according to claim 1, further comprising a light reflection layer between the ferromagnetic material thin film layer and the projections and the base material. 4. The forgery prevention thread according to claim 1, wherein an adhesive layer is provided on a surface of the substrate opposite to a surface on which the convex portion is formed. 5. The thread for preventing forgery according to claim 1, wherein an adhesive layer is provided on the ferromagnetic material thin film layer. 6. A forgery prevention sheet provided with a forgery prevention thread according to claim 1 incorporated in a base paper, wherein the base paper exposes the thread intermittently. Forgery prevention paper, comprising a cover and a cover between the exposed portion and intermittently covering the thread. 7. The anti-counterfeit paper according to claim 6, wherein a plurality of exposed portions and covering portions are provided, and a plurality of anti-counterfeit threads are formed.