JP5636750B2 - Thread and anti-counterfeit paper - Google Patents

Description

  The present invention relates to a thread used for a paper medium having an anti-counterfeit effect and a thread paper incorporating the thread, and more particularly to a thread and thread paper of a type into which a magnetic agent for performing magnetic reading verification is introduced. .

  Conventionally, as a measure to prevent counterfeiting in security-sensitive media such as banknotes, passports, official certificates, gift certificates, etc., a special gloss is created by embedding threads made of resin or aluminum foil on the media paper. In other words, a method for preventing forgery by copying or printing is used as a means for preventing forgery.

Such a thread is also called a security thread, and the paper that has been engraved with it requires special paper manufacturing technology, so it is difficult to forge with a copy or scanner, or forgery at the printing stage. can do.
However, in recent years, forged products of threads have come to the market, and simple threads alone are insufficient as a means for preventing forgery. Therefore, a technique has been proposed in which a special magnetic agent is introduced into the thread, the presence or absence of the magnetic agent is detected, and this is read by a magnetic reader to determine the authenticity of the medium. (See Patent Document 1)

  Magnetic sled paper that can detect magnetism as described above is generally difficult to obtain due to its special manufacturing method, and it is counterfeited by ordinary means due to its unique magnetic properties. It can be almost impossible. Thereby, the forgery prevention means with high security is realizable.

  Conventionally, as the main material of the magnetic agent used for the magnetic thread, metals such as iron, cobalt and nickel, or metal oxides such as ferrite (iron oxide compound) and chromium oxide have been used. Magnetic materials are used as fine powders mixed with ink or resin.

JP-A-7-32778 US Patent No. 7,179,393

  The magnetic agent used for the thread is darkly colored black, black gray or brown due to the optical properties of the metal. However, if a thread with such a magnetic agent is incorporated on paper, the color of the magnetic agent will appear on the surface of the medium through the paper layer, which greatly impairs the design and aesthetics of the paper. was there. This is a big problem because the product value is low if the design of the actual product is low.

  For such problems, a proposal has been made to hide the magnetic agent in the thread by introducing a metal layer having the property of a non-magnetic agent so that the color of the magnetic agent cannot be seen from the surface of the paper. Has been. (See Patent Document 2)

However, in this method, it is necessary to add a step of introducing a metal layer of a non-magnetic agent at the time of thread manufacture, which increases the number of steps, deteriorates the manufacturing throughput, and further increases the product cost. was there.

  The present invention has been made to solve the above-mentioned problems, and it is possible to improve the design and aesthetics of the medium by preventing the color of the magnetic agent engraved on the thread from being seen from the surface of the medium. It is another object of the present invention to provide a security thread that does not increase the throughput and cost of thread manufacture, and a forgery prevention sheet using the security thread.

The thread according to the invention of claim 1 is formed by laminating a magnetic layer containing a white magnetic agent or a colorless transparent magnetic agent on one surface of a multilayer interference film , and having a thickness of 1 μm between the substrate and the magnetic layer. A diffractive structure forming layer made of UV curable ink having a diffraction grating in which concave and convex grooves are engraved with a spacing of 0.3 μm and a depth of 0.4 μm and a vapor deposition processed layer made of aluminum with a thickness of 50 nm are laminated, and a white magnetic agent is laminated. The mask ink made of the vinyl chloride / vinyl acetate copolymer resin contained is printed and applied in a pattern with a thickness of 1 μm to form a white magnetic mask layer, and the exposed portion of the vapor-deposited layer other than the masked region is demetalized. The thread is formed by forming an adhesive made of a vinyl chloride vinyl acetate copolymer resin in which a white fine silica filler is dispersed on both surfaces of the laminate. A.

A thread according to a second aspect of the present invention is characterized in that an adhesive layer containing an adhesive is provided on both sides of the thread including the base material and the magnetic layer.

The thread according to the invention of claim 3 is characterized in that the magnetic agent contains titanium oxide and iron oxide.

The anti-counterfeit paper according to the invention of claim 4 is characterized in that the thread according to any one of claims 1 to 3 is incorporated into the paper.

  According to the present invention, by making a forgery-preventing paper incorporating a thread into which a white or colorless and transparent magnetic agent is introduced, it is possible to prevent the magnetic layer from being seen through the surface of the paper, The anti-counterfeit paper can be manufactured without increasing the cost and throughput of the thread manufacturing and improving the design and appearance of the paper.

It is sectional drawing which shows the structure of the 1st Example of the thread | sled of this invention. It is sectional drawing which shows the structure of the 2nd Example of the thread | sled of this invention. It is sectional drawing which shows the structure of the 3rd Example of the thread | sled of this invention.

Embodiments of a thread and anti-counterfeit paper according to the present invention will be described below in detail with reference to the drawings. First, an example of using it as an embedded thread is shown.
FIG. 1 is a cross-sectional view showing a configuration of a first embodiment of a thread according to the present invention, and this embodiment shows a configuration of an embedding thread for embedding in a sheet.

(First embodiment)
As shown in FIG. 1, a white magnetic layer 3 is laminated on one surface of a thread base material 2 to form a pattern. The white magnetic layer 3 may be patterned in contact with the substrate 2 or may be laminated on the entire surface. The white magnetic layer 3 may be formed by, for example, printing by a printing method using magnetic ink in which white magnetic particles are mixed with printing ink to form a pattern.

  Further, the base material 2 and the white magnetic layer 3 are sandwiched, and the adhesive layer 4 is laminated on both the front and back surfaces, thereby constituting the thread 1 as a whole. The adhesive layer 4 is coated with an adhesive for adhering to a medium such as anti-counterfeit paper, and when the thread 1 is incorporated into the paper, the adhesive layer bonds the thread 1 and the paper. To do.

In general, a light-impermeable material is used as the substrate 2, but a light-transmitting material can be used depending on the purpose and application. In the case of light impermeability, there are many white base materials.
Examples of the material of the light-impermeable substrate include cellophane, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyphenylene ether, liquid crystal polymer, polyvinyl chloride, polyester, polyamide, polycarbonate, polyethyl methacrylate, and polystyrene. Synthetic resin films are used, and these can be used as a simple substance or a composite.
In consideration of characteristics such as water resistance and heat resistance, an appropriate material can be used for these materials according to the purpose of use of the medium into which the thread is formed.

  Further, white pigments such as titanium oxide, silica, calcium carbonate, calcium sulfate may be kneaded into these materials. Furthermore, colorants (pigments, dyes, etc.) other than white may be kneaded, and the pigment may be applied to the surface of the substrate 2.

  Although the thickness of the base material 2 is not particularly limited, it is generally preferable that the thickness of the paper making thread is 5 to 25 μm. If it is this thickness, the thickness of the paper in which the thread is engraved does not rise up visually or causes various problems during processing.

  In addition, the light impermeability of the base material 2 does not completely block light, but may be as long as the printed layer on the opposite side cannot be seen through when viewed through one side. .

The white magnetic layer 3 is formed by using a magnetic material. In order to form a pattern by a printing method, it is desirable to use a magnetic ink containing a magnetic agent in the printing ink as a material.
A magnetic ink is generally obtained by adding a magnetic powder to an organic solvent together with a binder and necessary additives (dispersant (surfactant), lubricant, plasticizer, etc.) and thoroughly kneading to uniformly disperse. . At this time, white magnetic ink can be obtained by using, for example, white magnetic powder made of titanium oxide or the like. In some cases, magnetic particles are used as nuclei and fine particles of a white substance such as a white pigment are fixed on the surface thereof.

The white magnetic layer 3 can be obtained by printing on the base material 2 using such a white magnetic ink. At this time, solid printing or an arbitrary pattern can be printed on the entire surface.
When the substrate 2 is white, the printed portion using the white magnetic ink is hardly noticeable, and as a result, the white magnetic layer 3 is concealed when viewed from either the front or back side.

A colorless and transparent magnetic agent can also be used. As the colorless and transparent magnetic agent, for example, a powdery magnetic agent obtained by adhering tin oxide to magnetic iron oxide particles and mixed with ink is used. When this is held, a colorless and transparent magnetic layer can be formed, so that the magnetic layer is concealed as in the case of the white magnetic layer.

  The configuration of the thread 1 shown in FIG. 1 is a so-called embedded thread. For example, if the medium is paper, the white magnetic layer 3 in the thread 1 is made a magnetic material by making the thread 1 into paper. It can be used as anti-counterfeit paper.

  Furthermore, if magnetic information is recorded by exciting the paper using, for example, an excitation magnetism generator, the information can be read by the magnetic reader. A variety of magnetic information can be recorded by devising the magnetic material, magnetic recording method, recording location, type of magnetic signal, etc., and forgery prevention means can be obtained by reading and collating this magnetic information. .

  In the case of anti-counterfeit paper using such embedded threads, since the paper is almost white or a color close to it, the white magnetic layer is not seen through the surface, and the aesthetics and design of the paper are impaired. It will not be.

(Second embodiment)
Next, the configuration of a thread having a visual effect will be described.
FIG. 2 is a diagram showing the configuration of a second embodiment of the thread according to the present invention. In this embodiment, a so-called window thread is used in which a part of the thread is exposed on the paper surface. The configuration is shown.

  In FIG. 2, a diffractive structure forming layer 12, a vapor-deposited layer 15 and a white magnetic layer 13 are laminated in this order on one surface of a substrate 11, and an adhesive layer 14 is laminated on both outer surfaces thereof.

  Since the thread of this configuration has a visual effect, the material of the base material 11 is preferably a light-transmitting resin material, such as vinyl acetate resin, ethylene vinyl acetate copolymer resin, vinyl chloride vinyl acetate. Copolymer resins, polyester resins, polyester urethane resins, acrylic urethane resins, epoxy resins, epoxy urethane resins, polycarbonate urethane resins, butyral resins, chlorinated propylene resins, and the like are used.

  The diffraction structure forming layer 12 is formed with a diffraction grating in which a plurality of grooves having a concavo-convex structure are two-dimensionally arranged on one surface, and is formed by, for example, an embossing process using a light-transmitting resin. . The vapor deposition layer 15 has a metal thin film vapor-deposited on the diffractive structure forming layer and functions as a light reflection layer.

  The metal thin film of the vapor deposition layer 15 is made of a metal material selected from, for example, aluminum, silver, tin, chromium, nickel, copper, gold, or an alloy thereof, and is formed into a thin film such as a vacuum vapor deposition method or a sputtering method. It is formed using means. The film thickness of the metal thin film may be appropriately determined according to the size and depth of the grooves of the diffraction grating, but generally a range of 1 to 100 μm is used.

The white magnetic layer 13 uses a magnetic material as in the first embodiment. For example, the white magnetic layer 13 is patterned by a printing method using a magnetic ink containing a magnetic agent in a printing ink.
Also, a colorless and transparent magnetic agent can be used in place of the white magnetic material.

  The thread 10 shown in FIG. 2 can be used as a so-called window thread in which a part of the thread is intermittently exposed on the surface of the sheet when the sheet is drawn on the forgery prevention sheet. As shown in FIG. 2, the side closer to the base material 11 is the window opening side, an opening is provided in the paper to form the window opening, and the thread 10 is drawn into the window opening of the paper, thereby The thread is exposed.

At this time, a special visual effect is observed from the window opening.
That is, when incident light from the outside enters the diffraction structure forming layer 12 through the adhesive layer 14 and the base material 11 from the window opening side and is reflected by the vapor deposition processing layer 15, the wavelength of the light is reflected by the grooves of the concavo-convex structure. A diffraction effect with dispersion occurs, and the color appears to shift to various colors depending on the position or angle of the observer's viewpoint. The reflected light from the metal deposition layer 15 also appears to have a metallic luster.
A thread having such a diffractive structure is difficult to counterfeit and retains a high anti-counterfeit effect.

(Third embodiment)
Next, another embodiment of a thread having a visual effect will be described.
FIG. 3 is a diagram showing the configuration of a window thread as a third embodiment of the thread of the present invention. In the thread 20, a diffractive structure forming layer 22 is laminated on a base material 21, and a diffraction grating in which grooves of a plurality of uneven structures are two-dimensionally arranged on one surface of the diffractive structure forming layer 22 is a first interface portion. The white magnetic mask layer 23 is laminated and formed in two regions of 25a and the second interface portion 25b, and in contact with the second interface portion 25b.

  The substrate 21 is preferably a light transmissive resin material, as in the second embodiment.

A metal thin film formed by vapor deposition is laminated on the second interface portion 25b, and there is no metal thin film on the first interface portion 24a.
As a manufacturing method thereof, after depositing a metal thin film on the entire surface of the diffraction structure forming layer 22, a white magnetic mask layer 23 is further laminated thereon by a printing method.
Next, by using the white magnetic mask layer 23 as a protective film, the metal thin film is subjected to a demetalization process, whereby the metal thin film remains in the second interface portion 24b protected by the white magnetic mask layer 23 and is not protected. The metal thin film is removed from the interface 24a.

  Furthermore, the adhesive layer 24 is laminated on both surfaces to form the thread 20. The thread 20 is a window thread in which the side close to the substrate 21 is the window opening side and the side close to the white magnetic mask layer 23 is the windowless side.

The thread 20 is exposed from the window opening by making the thread 20 into the window opening of the forgery prevention paper. The light incident from the window opening is reflected by the second interface 24b where the metal thin film is laminated through the diffraction grating of the diffractive structure forming layer 22, so that the diffraction effect is applied as in the second embodiment. It looks shifted to a variety of colors.
The thread having the diffractive structure is difficult to counterfeit and can retain a high anti-counterfeit effect.

Moreover, the base material 21 can also be comprised with a multilayer resin film. For example, a multilayer interference film in which a plurality of films made of materials that are transparent but have different optical characteristics can be used. In the multilayer interference film, incident light generates wavelength dispersion due to the interference effect in the film, so that a more complicated visual effect can be obtained when viewed from the window opening side.
And since the multilayer interference film itself used for such a purpose is also difficult to forge, a higher forgery prevention effect can be obtained.

(Production procedure of Example)
In the thread configuration shown in the third embodiment, a thread manufacturing procedure will be described below.
(i) Using a multilayer interference film having a thickness of 16 μm as a base material, a UV curable ink serving as a fine diffractive structure forming layer was applied thereon with a thickness of 1 μm using a gravure coating method, followed by drying and aging.
(ii) An embossed original plate having a diffraction grating pattern in which concave and convex grooves were carved at intervals of 0.3 μm and a depth of 0.4 μm was prepared. The cylinder roll equipped with this original plate is heated, and the UV curable ink coating layer is embossed at 100 ° C., and then the ink is cured by irradiating ultraviolet rays from the film substrate side. A formed diffraction structure forming layer was obtained.
(iii) An aluminum metal thin film having a thickness of 50 nm was laminated on the diffraction structure forming layer by a vapor deposition method as a vapor deposition processed layer.
(iv) On the vapor-deposited layer, a mask pattern made of a vinyl chloride vinyl acetate copolymer resin (vinyl acetate) containing a white magnetic agent is printed with a thickness of 1 μm using a gravure printing method. The white magnetic mask layer was obtained by coating. Next, the exposed portion of the vapor deposition processing layer other than the masked region was removed by demetalizing with an alkaline solution.
(v) An adhesive made of vinyl chloride in which a fine silica powder filler was dispersed was applied to the front and back surfaces of the laminate produced in (iv) at a thickness of 2 μm by a gravure coating method.

The manufacturing procedure of the embossed original plate (ii) will be described.
A photosensitive positive resist was applied onto a glass plate serving as a substrate, and then a diffraction grating pattern was drawn by electron beam drawing, followed by development processing to obtain a resist pattern. The resist pattern surface was coated with a conductive film by a sputtering method to produce a mother die, and an embossed original plate was obtained using a nickel electroforming method.

A forgery-preventing paper was obtained by using the thread obtained by the above-described manufacturing procedure as a window thread and making the thread into a paper having an opening.
When this anti-counterfeit paper is visually observed from the front and back, the magnetic mask layer in the thread is almost the same color as the paper and cannot be distinguished. , The design of the ticket will not be impaired.
That is, the effect of expanding the use without giving a restriction to the design of these anti-counterfeit papers was obtained.

  In addition, according to the manufacturing procedure, the magnetic mask layer can be formed only by a normal printing method, and it is not necessary to form a metal mask layer for concealing the magnetic mask layer so as not to impair the design productivity. . Therefore, the manufacturing process is not complicated and the manufacturing load is not increased.

  In addition, this invention is not specifically limited to said Example, It can apply to a various structure.

For example, if a magnetic mask layer is formed using a colorless and transparent magnetic material, the magnetic mask layer itself cannot be seen. Therefore, the window thread using the magnetic mask layer does not show the magnetic mask layer from the outside, which impairs the design. There is nothing.
The colorless and transparent magnetic material may be a known material, such as iron oxide particle powder coated with tin oxide or tin hydroxide.

  The thread and anti-counterfeit paper according to the present invention can be applied to anti-counterfeit media with various security provided by magnetic information, such as banknotes, passports, public certificates, and gift certificates.

DESCRIPTION OF SYMBOLS 1,10,20 ... Thread 2,11,21 ... Base material 3,13 ... White magnetic layer 23 ... White magnetic mask layer 4, 14, 24 ... Adhesive layer 12, 22 ··· Diffraction structure forming layer 15 ··· deposition layer 25a ··· first interface portion 25b ··· second interface portion

Claims (4)

A magnetic layer containing a white magnetic agent or a colorless and transparent magnetic agent is laminated on one surface of the multilayer interference film , and a thickness of 1 μm between the base material and the magnetic layer is formed with a gap of 0.3 μm and a depth of the concave and convex grooves. From a vinyl chloride-vinyl acetate copolymer resin containing a white magnetic agent, a diffractive structure-forming layer made of UV curable ink having a diffraction grating engraved at 0.4 μm and a vapor-deposited layer made of aluminum having a thickness of 50 nm. The mask ink is printed and applied in a pattern with a thickness of 1 μm to form a white magnetic mask layer, and the exposed portion of the vapor-deposited layer other than the masked region is removed by demetalization, A thread comprising an adhesive made of a vinyl chloride vinyl acetate copolymer resin in which a fine silica powder filler is dispersed on both sides .   The thread according to claim 1, further comprising an adhesive layer containing an adhesive on both sides of the thread including the base material and the magnetic layer. The thread according to claim 1, wherein the magnetic agent contains titanium oxide and iron oxide.   An anti-counterfeit paper, wherein the thread according to any one of claims 1 to 3 is engraved on the paper.

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