JP4373056B2 - Transfer foil for authenticity judgment body and authenticity judgment body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transfer foil for authenticity determination body and an authenticity determination body to which the transfer foil is transferred.
More specifically, the present invention relates to a transfer foil provided with a tint block print using a normal printing ink on a resin layer made of cholesteric liquid crystal exhibiting a rainbow-colored interference color, and an authenticity determination body formed by transferring the transfer foil.
The application field of the authenticity determination transfer foil and authenticity determination object of the present invention includes various guarantees, securities such as gift certificates, stock certificates, tickets and lotteries, tickets and entrance tickets, passports, financial institutions and life insurance. -Transaction details and various certificates used in non-life insurance, public competition voting tickets, price and type display tags and labels, etc.
[0002]
[Prior art]
Conventionally, in order to prevent counterfeiting of this kind of cash vouchers, forgery prevention technology is provided in which a color change printing layer that exhibits a rainbow interference color depending on the viewing angle is provided.
Such a color change printing layer is formed by printing with a color change ink such as pearl ink. An ink exhibiting a rainbow interference color contains a pigment that multi-reflects light, and the color appears to change due to interference of light reflected by the pigment.
Therefore, the color change effect is greater as the amount of light reflected by the pigment increases. Therefore, the color change printing layer is often printed by stencil printing such as screen printing or intaglio printing such as gravure printing so that the thickness of the color change printing layer increases so that the number of pigments that multiple reflection of light increases. .
However, since the color change printing layer is often printed by gravure printing, coating, or screen printing, there is a problem that the manufacturing cost increases.
[0003]
In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. 2000-6564 “Anti-counterfeit printing medium and its preparation method” provides a color change printing layer printed with a pearl pigment on a printing medium such as a gift certificate or stock certificate, A forgery-preventing print medium is proposed in which a part of the color-change print layer is hidden in an invisible pattern by offset printing to form specific information.
Japanese Patent Laid-Open No. 6-255234, “Dichroic Intaglio Print” proposes a dichroic intaglio print that forms an intaglio image with an intaglio ink containing a colored pearl pigment on a white background. However, in the case of this printed matter, since the latent image is not hidden in the pearl printing, a high degree of forgery prevention cannot be achieved.
In general, these printing media using pearl pigments have a problem that the color change is weak and a clear latent image cannot be displayed.
[0004]
There are also prior arts that use cholesteric liquid crystal pigments, regardless of pearl pigments. Japanese Patent Application Laid-Open No. 7-304983 discloses a pigment having a platelet structure made of cholesteric liquid crystal. However, cholesteric liquid crystal pigments need to be scale-like and large in order to take advantage of their properties, and usually only a solid pattern with a relatively large area can be reproduced by printing with a silk screen or gravure. There are large restrictions and poor design. Further, there is a problem that a single body does not have a latent image effect.
[0005]
International Publication No. WO00 / 13065 (PCT / JP 99/04641) discloses a hologram on a reflective film having circular polarization selectivity that reflects only one of left circularly polarized light and right circularly polarized light to generate reflected light. An authenticity identification film or the like that is provided with a forming portion is proposed. However, in the case of forming a hologram, there is a problem that preparation of a hologram master is complicated and requires a large amount of equipment, and a process such as replication is complicated and very expensive.
[0006]
[Problems to be solved by the invention]
The applicant of the present application has previously proposed a latent image display medium in which a cholesteric liquid crystal layer is printed on a medium without using a hologram (Japanese Patent Application No. 2002-139468). Not necessarily suitable for individual printing.
Therefore, the present invention has been conceived of a transfer foil for authenticity determination body using a cholesteric liquid crystal layer as a material that can be used more easily without being directly printed on a medium, and the present invention has been completed.
[0007]
[Means for Solving the Problems]
The first of the gist of the present invention for solving the above-mentioned problems is that a release layer / protective layer is provided on a base film, and has a selective reflectivity depending on the angle seen on the release layer / protective layer, and changes color. The resulting cholesteric liquid crystal layer is provided, and a copy-forgery-inhibited pattern printing using a normal printing ink is printed on a part of the liquid crystal layer with a colorant similar in color to that seen when the cholesteric liquid crystal layer is observed from the front. A transfer foil for authenticity determination body, characterized in that an adhesive is applied to the entire surface to provide an adhesive layer. Since it is such a transfer foil for authenticity determination body, it is difficult to duplicate and a counterfeit product can be easily detected.
[0008]
The second of the gist of the present invention for solving the above-mentioned problems resides in a true / false determining body characterized by transferring the authenticity determining body transfer foil to an authenticity identification object.
Since it is such a true / false determination object, it is difficult to duplicate and a counterfeit product can be easily detected.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The first aspect of the present invention relates to a transfer foil comprising a cholesteric liquid crystal layer having selective reflectivity and a color change depending on the viewing angle, and tint block printing, and the second aspect of the present invention is a authenticity determination body obtained by transferring the transfer foil. About.
The layer using the cholesteric liquid crystal may use an ink using a cholesteric liquid crystal piece as a pigment, or may apply a liquid crystal resin itself to a medium substrate and align it to form a liquid crystal coating film.
The tint block printing using ordinary printing ink may be any method such as intaglio printing, gravure printing, silk screen printing, etc. in addition to offset.
[0010]
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing a transfer foil for authenticity determination body of the present invention, FIG. 2 is a view showing a process of transferring the transfer foil for authenticity determination object to an authenticity identification object, and FIG. It is a top view of the authenticity determination body.
As shown in FIG. 1, the transfer foil 1 for authenticity determination body is provided with a release layer / protection layer 12 on a substrate film 11 as a medium, and a cholesteric liquid crystal layer 13 is provided on the release layer / protection layer 12. A copy-forgery-inhibited pattern printing 14 using a normal printing ink is provided on a part of the liquid crystal layer 13, and an adhesive layer 15 is provided as the uppermost layer.
[0011]
The peeling layer / protective layer 12 is a layer provided for facilitating peeling of the cholesteric liquid crystal layer 13 from the interface of the base film 11 of the transfer foil 1 for authenticity determination body. Since it also serves as a protective layer remaining on the tint block print 14, it is expressed as a peeling layer / protective layer 12.
The release layer / protective layer is preferably easily peelable from the base film 11 and has good adhesion to the cholesteric liquid crystal layer 13. A transparent resin having excellent printability and drying property is preferable.
In general, cellulose-based or rubber-based resins such as vinyl chloride and nitrified cotton are used, but an appropriate one is considered in consideration of peelability from the base film 11 and adhesion to the cholesteric liquid crystal layer 13. Select use. Therefore, it will be selected individually depending on the materials used for them.
[0012]
The cholesteric liquid crystal layer is a liquid crystal polymer having a helical structure and has a characteristic that the color tone continuously changes depending on the viewing direction.
Since the cholesteric liquid crystal layer has selective reflectivity, when the incident light has an incident angle θ, if the helical period of the liquid crystal is P, the average refractive index of the liquid crystal is n, and the wavelength is λ, P Selectively reflects light having a wavelength satisfying the Bragg reflection condition of cos θ = λ / n. In addition, at this time, according to the structure determined by the absolute configuration of the asymmetric carbon, only the right circularly polarized component or the left circularly polarized component of the light of wavelength λ is selectively reflected. Further, as is apparent from the equation of λ = n · P · cos θ, λ also varies depending on the angle of light incident on the cholesteric surface (film surface).
[0013]
Therefore, when the medium having the cholesteric liquid crystal layer 13 is tilted, a color different from the color visually recognized when observed from the original surface is displayed.
The color called cholesteric color is visible to the human eye as a unique beautiful color that cannot be produced by other means. These wavelength selective reflectivity, circularly polarized light selective reflectivity, color viewing angle dependency, and beautiful colors of cholesteric color are difficult to express with other substances or methods. The determination object is difficult to counterfeit, and it is possible to easily determine the authenticity of the counterfeit product, which is extremely effective in preventing forgery of the authenticity determination object.
[0014]
The cholesteric liquid crystal layer can be formed by a method in which a thermotropic cholesteric liquid crystalline polymer is heated to a temperature higher than its liquid crystal transition point to grow a liquid crystal structure and then rapidly cooled to fix the liquid crystal structure. .
The thickness of the cholesteric liquid crystal layer 13 is desirably about 1 μm to 20 μm in order to take advantage of the characteristics. In order to make the reflected light easier to observe, it may be transferred to a black authenticity identification object.
Various types of cholesteric liquid crystals are commercially available as coating resins, and these can be used.
[0015]
The tint block of the tint block print 14 using ordinary printing ink is not particularly limited, but a tint pattern or single-color tint pattern used for ordinary securities, certificate paper, banknotes, etc., or fine characters, geometric patterns, etc. Can be adopted. When the tint block printing 14 is printed with a colorant similar in color to the color visually recognized when the cholesteric liquid crystal layer 13 is observed from the front, it is difficult to distinguish at a glance and the latent image effect can be enhanced.
[0016]
The adhesive layer 15 may be either a material having adhesiveness itself or a heat-sealable adhesive to which adhesiveness is imparted by heating, and the cholesteric liquid crystal layer 13 is an authentic identification object. Any material can be used as long as it can be adhered to. However, in the former case, since a protective coated paper or the like may be further required, a heat-sealable adhesive is usually used.
Various materials can be used for the material used for these, for example, cellulose-based materials, such as a vinyl chloride system, a polyester system, and CMC, can be used.
The adhesive can be colored by adding a light dye. Thereby, the effect that the designability and appearance are improved is obtained.
[0017]
The material of the base film 11 is selected according to the purpose of use and is not particularly limited, but generally a plastic base material is preferable.
In particular, polycarbonate (PC), polyvinyl alcohol (PVA), polysulfone (PSF), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyarylate (PAr), polyethylene terephthalate (PET), triacetyl cellulose (TAC) ), Diacetyl cellulose (DAC), and polyethylene-ethyl vinyl alcohol (PE-EVA).
Since the base film 11 is often discarded after the transfer, it may be a thin material as long as it does not interfere with the manufacturing and transfer processes. Usually, the thickness of about 15-50 micrometers is used.
[0018]
When transferring the authenticity determination object transfer foil to the authenticity identification object, as shown in FIG. 2, the authenticity determination object transfer foil 1 is applied to the authenticity identification object 3 placed on a flat plate. The cholesteric liquid crystal layer 13 can be thermally transferred to the authenticity identification object 3 by pressing with the heating roller 5 and pressure bonding.
However, the transfer method is not limited to the roll transfer method shown in FIG. 2, and the transfer foil may be pressed and transferred to the authenticity identification object 3 placed on a flat plate by a flat pressure press. The authenticity identification object 3 and the transfer foil 1 may be aligned and passed between the two thermocompression-bonding rollers and transferred.
At this time, the base film 11 is peeled and removed, and the peeling layer / protective layer 12 remains on the authenticity identification object 3 side. Thereby, the authenticity determination body 2 of the present invention is completed.
After the transfer, the release layer / protective layer 12 functions as the protective layer 12h.
[0019]
As shown in the plan view of FIG. 3, the authenticity determination object 2 is partially transferred with the authenticity determination object transfer foil 1 to the transferred region 4 of the authenticity identification object 3. The entire surface may be transferred instead of the partial transfer. However, since the cholesteric liquid crystal layer exhibits a remarkable discrimination effect, the effect is sufficient even with the partial transfer.
The copy-forgery-inhibited pattern print 14, the cholesteric liquid crystal layer 13, and the protective layer 12 h are transferred to the transferred region 4 by the adhesive layer 15. FIG. 3A shows an example in which the tint block print 14 is a fine character pattern, and FIG. 3B shows an example in which it is a geometric pattern.
On the authenticity identification object 3, a general print pattern 6 for displaying a display of a security or the like or a face value is printed in advance.
[0020]
【Example】
An embodiment of the present invention will be described with reference to FIGS.
(Example)
After gravure printing a background pattern, a pattern, etc. on a cholesteric liquid crystal film obtained by coating a base film (PET having a thickness of 25 μm) 11 with a release layer / protective layer 12 and a costelic liquid crystal layer 13, an aqueous heat sealant (cellulose-based) After adding 0.5% of a blue water-based dye, it was coated by the gravure reverse method to obtain a transfer foil 1 for authenticity determination.
[0021]
The authenticity determination body transfer foil 1 was transferred to the authenticity identification object 3 by the heating roller 5 to obtain an authenticity determination body (gift certificate) 2.
The obtained authenticity determination body 2 could be clearly distinguished from an authenticity identification object having no transferred area because the transferred area 4 had different colors depending on the viewing angle.
[0022]
【The invention's effect】
As described above in detail, according to the present invention, the following effects can be obtained.
The transfer foil for authenticity determination body and the authenticity determination object of the present invention use the viewing angle dependence, wavelength selectivity, and circular polarization selectivity of cholesteric color of cholesteric liquid crystal, and are difficult to counterfeit. False determination is very easy.
Further, since not only the cholesteric liquid crystal layer but also tint block printing is added, unique information can be added and the range of use can be further widened.
The optical rotation and selective reflectivity of the cholesteric liquid crystal cannot be reproduced by a copying machine or a scanner. In this respect as well, the effect of preventing forgery is enhanced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a transfer foil for authenticity determination body of the present invention.
FIG. 2 is a diagram showing a process of transferring an authenticity determination body transfer foil to an authenticity identification object.
FIG. 3 is a plan view of the authenticity determination body of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transfer foil for authenticity determination body 2 Authenticity determination object 3 Authentic identification object 4 Transfer area 5 Heating roller 6 General printing pattern 11 Base film 12 Peeling layer / protection layer 12h Protection layer 13 Cholesteric liquid crystal layer 14 Background pattern printing 15 Adhesive layer

Claims (3)

On the base film, a release layer / protective layer is provided, a cholesteric liquid crystal layer having selective reflectivity and a color change is provided depending on the angle seen on the release layer / protective layer, and a part of the liquid crystal layer is The tint block print using normal printing ink was printed with a colorant similar to the color seen when the cholesteric liquid crystal layer was observed from the front, and an adhesive was applied to the entire surface to provide an adhesive layer. Transfer foil for authenticity determination body characterized by The transfer foil for authenticity determination body according to claim 1, wherein the adhesive layer is colored. An authenticity determination object obtained by transferring the authenticity determination object transfer foil according to claim 1 or 2 to an authenticity identification object.

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