JP5678428B2 - Anti-counterfeit medium and method for producing the same, and adhesive label and transfer foil having anti-counterfeit medium - Google Patents

Description

  The present invention relates to an anti-counterfeit medium having a copy-preventing function, a manufacturing method thereof, and an adhesive label and transfer foil having the anti-counterfeit medium.

  Conventionally, securities such as banknotes, gift certificates, passports, and authentication media have been pasted with a medium that is difficult to forge as a countermeasure against forgery. Such a medium has an overt function in which the application of anti-counterfeiting measures is easily recognized and the determination of authenticity by visual observation is easy, or the authenticity determination using a verifier is generally difficult to understand for application to articles. It has a covert function that makes it possible to make a determination only when it is intentionally performed.

  As an overt function, in recent years, since a special optical effect can be discriminated at a glance, anti-counterfeit media using optical elements such as diffraction gratings and holograms are used for various articles.

  However, since diffraction gratings and holograms are widely used for packaging materials and are easily available, a forgery prevention medium that is more difficult to forge is required.

  With respect to this problem, Patent Document 1 has a pattern in which diffraction grating patterns have patterns with the same spatial frequency and directions different from each other by 90 degrees and are reflected and diffracted in the pattern when illuminated with illumination light and observed with the naked eye. Using this difference, we proposed a diffraction grating pattern as an anti-counterfeit medium having an anti-copying function in which the color and brightness of the entire pattern change depending on the viewing angle.

  In recent years, a latent image technique using a polarization technique has been proposed as a covert function, and a latent image appears by overlapping a polarizing film to determine authenticity.

Japanese Patent No. 3458470

  In the proposal of the diffraction grating pattern as the anti-counterfeit medium having the above-described anti-copying function, the anti-counterfeit medium is manufactured through two independent processes of forming the reflective layer after forming the diffraction grating pattern. The load on manufacturing and quality control is large.

  The present invention is proposed in view of the above-mentioned problems, and the problem to be solved by the present invention is to provide a forgery prevention medium having a structure capable of easily obtaining a forgery prevention medium having a copy prevention function. Is to provide. Another object of the present invention is to provide a simple method for manufacturing the forgery prevention medium. Another problem to be solved by the present invention is to provide an adhesive label and a transfer foil having the anti-counterfeit medium.

As means for solving the above problems, the invention according to claim 1 is an anti-counterfeit medium having an optical functional layer patterned on a support substrate and a reflective layer in this order, the optical functional layer being A plurality of regions having different optical orientation directions in a layer surface having optical anisotropy formed by a plurality of micro cracks in a certain direction, and the plurality of micro cracks in the certain direction are formed on the optical functional layer in the layer surface. An anti-counterfeit medium that is arranged along an orientation direction, and in the plurality of regions, an intensity ratio of scattered light and specular reflection light changes according to a light projection direction with respect to an alignment direction of the microcracks. It is.

  The invention according to claim 2 is the anti-counterfeit medium according to claim 1, wherein the optical functional layer is made of liquid crystal molecules.

  In the invention according to claim 3, the optical functional layer is oriented in different directions of 0 °, 45 °, and 90 °, and the oriented optical functional layer in the layer plane is a microcrack along the orientation direction. The anti-counterfeit medium according to claim 1, wherein the medium includes a portion including a portion and a portion not including a microcrack.

The invention according to claim 4 is a manufacturing method for manufacturing the forgery prevention medium according to any one of claims 1 to 3, wherein the optical functional layer having an incompletely cured portion is patterned on the support substrate. After forming, by forming a reflective layer by physical vapor deposition, a plurality of microcracks along the orientation direction of the optical functional layer in the layer plane are formed in the optical functional layer of the incompletely cured portion of the base This is a method for manufacturing a forgery prevention medium.

  The invention according to claim 5 is an adhesive label comprising an adhesive layer supported on a release paper on one side of the forgery prevention medium according to any one of claims 1 to 3.

  The invention according to claim 6 is the adhesive label according to claim 5, wherein the forgery prevention medium is provided with notches and / or perforations.

  The invention according to claim 7 is provided with a release layer between the support base material of the anti-counterfeit medium according to any one of claims 1 to 3 and the optical functional layer, and is provided on the reflective layer of the anti-counterfeit medium. The transfer foil is characterized by comprising an adhesive layer.

  The anti-counterfeit medium of the present invention can be manufactured relatively easily in a short process. In addition, the appearance changes depending on the direction of the light at the time of observation, while the density of the pattern changes depending on the scanning direction of the light of the copying apparatus. Therefore, the overt function and the covert function can be provided simultaneously. Further, by providing the adhesive label and the transfer foil having the anti-counterfeit medium of the present invention, it is possible to easily give a forgery preventing function to various articles.

It is a conceptual diagram for demonstrating an example of the structure of the forgery prevention medium of this invention, Comprising: (a) is a schematic front view, (b) is a schematic sectional drawing between AB. It is explanatory drawing which shows an example of the copy which copied the forgery prevention medium of FIG. FIG. 7 is an explanatory diagram illustrating another example of a copy obtained by copying the forgery prevention medium of FIG. 1. It is a schematic front view for demonstrating the other example of the structure of the forgery prevention medium of this invention. It is explanatory drawing when the forgery prevention medium of FIG. 4 is observed visually. It is explanatory drawing when observing the forgery prevention medium of FIG. 4 using the verification device from the base material side. FIG. 5 is an explanatory diagram illustrating an example of a copy obtained by copying the forgery prevention medium of FIG. 4. FIG. 5 is an explanatory diagram showing another example of a copy obtained by copying the forgery prevention medium of FIG. 4. It is a schematic cross section of the adhesive label using the forgery prevention medium of this invention. It is a schematic cross section of the transfer foil using the forgery prevention medium of the present invention.

  Hereinafter, embodiments of a forgery prevention medium according to the present invention and a manufacturing method thereof will be described in detail with reference to the drawings.

  FIG. 1 is a conceptual diagram for explaining an example of the structure of an anti-counterfeit medium according to the present invention, where (a) is a schematic front view, and (b) is a schematic cross-sectional view taken along a dashed line A-B. is there. The anti-counterfeit medium of the present invention has a structure in which a plurality of optical functional layers 1 and 2 and a reflective layer 4 are overlaid thereon on a support substrate 3, and the plurality of optical functional layer regions are at least different. A region having optical anisotropy is included. For example, as shown in FIG. 1 (a), both regions 1 and 2 having different optical anisotropies in the optical functional layer surface are different from each other in that the region 1 exhibits vertical optical anisotropy. Each region 2 has a different optical anisotropy in a certain direction, such as a lateral optical anisotropy. Further, the optical anisotropy of each region is formed by arranging a plurality of microcracks in a certain direction. That is, the directionality in which microcracks are formed gives optical anisotropy.

  In the example of FIG. 1, a region 1 having a longitudinal microcrack showing the optical anisotropy in the longitudinal direction and a region 2 having a microcrack in the lateral direction showing the optical anisotropy in the lateral direction have specific patterns. Forming. With respect to this pattern, light is scattered most when the incident direction of light incident from the outside onto the optical functional layer surface is perpendicular to the alignment direction of the microcracks in each region, and the projection direction of the incident light is parallel to the alignment direction. The case is closest to specular reflection. When the light projection direction and the micro crack alignment direction are in an intermediate relationship between vertical and parallel, the intensity ratio between the scattered light and the specular reflection light continuously changes. For this reason, in this example, the letter “TP” appears due to the contrast between the scattered light and the specular reflection light. Further, when the direction of light irradiation is rotated by 90 °, the part where the scattered light and the specular reflection light return is reversed. Therefore, the contrast of the pattern looks different depending on the viewing angle.

  As the optical functional layer, liquid crystal molecules can be used. Microcracks can be formed in the layer of liquid crystal molecules by a treatment at the time of forming a reflective layer, which will be described later. In this case, the factor determining the alignment direction of the microcracks is the alignment direction of the liquid crystal molecules. As a method of aligning liquid crystal molecules biaxially, it can be formed by applying a liquid crystal material on an alignment film in which the alignment treatment direction is partially changed. For the alignment treatment of the alignment film for aligning the liquid crystal material, for example, a photo alignment method or a rubbing alignment method can be used.

  The photo-alignment method is a method in which the alignment film is irradiated with anisotropic light such as polarized light or non-polarized light from an oblique direction to induce rearrangement of molecules in the alignment film or anisotropic chemical reaction. In this method, anisotropy is imparted to the alignment film, whereby the liquid crystal molecules are aligned. Examples of the photo-alignment mechanism include photo-anisotropy of azobenzene derivatives, photo-dimerization and crosslinking of derivatives such as cinnamic acid ester, coumarin, chalcone and benzophenone, and photolysis of polyimide and the like.

  Specifically, it is performed by pattern exposure with polarized light in an appropriate wavelength band or non-polarized light from an oblique direction. Also, when aligning in the biaxial direction, such as a polarized latent image portion and a polarized background portion, pattern exposure is performed by covering the portion whose orientation direction is to be changed with a photomask, and further, the unexposed portion covered with the photomask. In order to process, exposure may be performed while changing the direction. Alternatively, after the entire surface is once exposed to pattern, it may be partially covered with a photomask and changed in direction to be exposed again.

  The rubbing alignment method is a method of rubbing an alignment film created by applying a polymer solution on a substrate with a cloth. The property of the alignment film surface changes in the rubbing direction and liquid crystal molecules are aligned in this direction. It is a thing. For the alignment film, polyimide, PVA, or the like is used.

  When aligning the optical axis in the biaxial direction, cover the part whose orientation direction is to be changed with a mask, rub it with a cloth, remove the mask, then cover the rubbed part with the mask and turn the direction again. After changing and rubbing with a cloth, the mask is removed. Alternatively, the entire surface may be rubbed with a cloth, partially covered with a mask, the direction may be changed, and the mask may be removed after being rubbed with a cloth.

  As a method for forming these alignment films, known methods such as a gravure coating method and a micro gravure coating method can be used.

  Liquid crystal materials include photocurable liquid crystal monomers with acrylates at both ends of the mesogenic group, polymer liquid crystals cured with EB or UV, polymer liquid crystals with mesogenic groups in the polymer main chain, and the molecular main chain itself. A liquid crystalline polymer can be used. The orientation of these liquid crystals can be promoted by heat treatment at a temperature slightly below the NI point at which phase transition occurs after coating.

  Next, a method for making a microcrack along the alignment direction of the liquid crystal layer will be described. Here, the case where it hardens | cures by irradiating an ultraviolet-ray to a photocurable liquid crystal is demonstrated.

  In the bond polymerization reaction on the liquid crystal layer surface, it is preferable to leave unreacted double bonds. As the ratio of unreacted double bonds, the residual double bond ratio of C = C can be used.

The residual double bond ratio is [spectrum intensity of absorption based on C = C bond (wave number: 810 cm ⁻¹ ) / spectrum intensity of absorption based on aromatic ring in liquid crystal molecule (wave number: around 1500 cm ⁻¹ )] Defined by

  When the polymerization is performed in a nitrogen atmosphere, the oxygen concentration in the nitrogen atmosphere is preferably 0.5% or more because sufficient reaction occurs if the oxygen concentration is too low. Further, the residual double bond ratio in the liquid crystal molecules is preferably 50% or more and 95% or less. Desirably, it is 70 to 90%. In the state where the residual double bond ratio is low and the curing has progressed too much, it becomes difficult to make microcracks along the alignment direction of the liquid crystal layer as described later, while in the extremely uncured state where the residual double bond ratio is high. This is because inconvenience in handling occurs due to surface stickiness and the like.

  As described above, since the unreacted double bond remains, the liquid crystal layer is not sufficiently cured. A liquid crystal layer that is not sufficiently cured has low heat resistance and is susceptible to shrinkage due to heat. Therefore, micro cracks along the alignment direction are likely to occur. As another method, microcracks can be formed in the liquid crystal layer along the alignment direction by stretching the supporting substrate.

  As conditions for polymerizing liquid crystal molecules, ultraviolet rays may be irradiated in the air, or ultraviolet rays may be irradiated in a nitrogen atmosphere. Depending on the liquid crystal material, the residual double bond ratio may be adjusted by the amount of ultraviolet irradiation.

  As a method for causing the heat shrinkage, it may be put in a high-temperature oven or the like, or the heat applied at the time of forming the reflective layer may be used. Is suitable. As described above, when heat is applied to a liquid crystal that is aligned in the biaxial direction and is insufficiently cured, heat shrinkage occurs along the alignment direction of the liquid crystal. When heat shrinkage does not occur in the support substrate and only heat shrinkage occurs in the liquid crystal layer, the liquid crystal layer cracks on the support substrate. Therefore, a microcrack along the alignment direction of the liquid crystal can be obtained. Since the liquid crystal molecules are regularly arranged in parallel, the microcracks have a parallel and regular shape such as a diffraction grating shape.

  As the supporting substrate, an unstretched film produced by extrusion or casting, a stretched film produced by stretching, or the like can be used. The stretched film includes a uniaxially stretched film and a biaxially stretched film depending on how to stretch, and both can be used.

  These unstretched films and stretched film materials include cellophane, polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyolefin (PO), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVA), polychlorinated. Examples thereof include vinyl, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), nylon, acrylic resin, and triacetyl cellulose (TAC) film.

  The reflective layer 4 is important in enhancing the contrast of the pattern based on the optical anisotropy caused by the microcracks in the optical functional layers 1 and 2 and giving clear display performance to the anti-counterfeit medium of the present invention. Examples of the material of the reflective layer include a single metal material such as Al, Sn, Cr, Ni, Cu, Au, and Ag, or a compound thereof.

A transparent reflective layer that is substantially transparent to light perpendicular to the film surface but exhibits reflection characteristics according to the refractive index with respect to oblique light can be used as a single layer or multiple layers. Examples of materials that can be used as the transparent reflective layer are listed below. The numerical value in parentheses following the chemical formula or compound name shown below indicates the refractive index n. Ceramics include Fe ₂ O ₃ (2.7), TiO ₂ (2.6), CdS (2.6), CeO ₂ (2.3), ZnS (2.3), PbCl ₂ (2.3 ), CdO (2.2), WO ₃ (5), SiO (5), Si ₂ O ₃ (2.5), In ₂ O ₃ (2.0), PbO (2.6), Ta ₂ O ₃ (2.4), ZnO (2.1), ZrO ₂ (5), MgO (1), SiO ₂ (1.45), MgF ₂ (4), CeF ₃ (1), CaF ₂ (1. 3-1.4), AlF ₃ (1), Al ₂ O ₃ (1), GaO (2) and the like. Examples of the organic polymer include polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), and polystyrene (1.60). Not limited.

  As a method for forming the reflective layer, a dry coating method is preferable. For example, a known method such as a vacuum deposition method, a sputtering method, or a CVD method can be appropriately used. In particular, a physical vapor deposition method such as a vacuum vapor deposition method or a sputtering method capable of appropriately heat-shrinking the liquid crystal layer during film formation is more preferable, and a method for providing an ink having a light reflection effect by a known printing method is included in the present invention. It is unsuitable.

  When a reflective layer is provided in a crack along the alignment direction of the liquid crystal by any of the methods described above, the direction of scattered light and specular reflection light changes depending on the alignment direction of the liquid crystal, that is, the direction of the crack. Then, when observed with the naked eye, the brightness of the portions with different orientation directions is recognized differently depending on the viewing angle, so that it becomes a forgery prevention medium having an overt function.

  Further, it will be described below that it can be used as a forgery prevention medium having a copy prevention function and other covert functions. For example, the case where the optical functional layers 1 and 2 in FIG. 1 form a pattern made of liquid crystal molecules and copies the pattern will be described as an example. When the light source of the copying apparatus scans the pattern, the direction in which the light receiving part of the specularly reflected light from the copy object moves in accordance with the scan (hereinafter referred to as “scan direction” for convenience), If the liquid crystal alignment direction, that is, the alignment direction of the microcracks is orthogonal, the pattern is copied, but the other part is not copied, and the appearance of the copy (copy) is clearly the original pattern By recognizing that it is different from, it can be determined that it is not a regular pattern but a copy.

FIG. 2 shows a copy of the pattern of FIG. 1 when the scanning direction is perpendicular to the vertical direction of FIG. 1A, that is, the alignment direction of microcracks corresponding to the liquid crystal alignment direction of the “TP” character pattern. The scattered portion is copied to form a white portion (bright portion) 5 of the copy, and the region other than the character pattern has a micro-crack alignment direction parallel to the scan direction, so that it becomes a specular reflection portion and is not copied. A black part (dark part) 6 is formed. That is, in FIG. 2, since the reflected light from the character “TP” is detected by the light receiving unit, the pattern is copied in white in the same figure, but the reflected light from around the character is not detected by the light receiving unit. It turns black in the figure.

  On the other hand, when the scanning direction is parallel to the horizontal direction of FIG. 1A, that is, the alignment direction of the microcracks corresponding to the liquid crystal alignment direction of the “TP” character pattern, the reflected light from the character “TP” as shown in FIG. Forms a black portion (dark portion) 6 of the copy without being detected by the light receiving portion, and reflected light from around the character is detected by the light receiving portion to form a white portion (bright portion) 5 of the copy. Therefore, a different copy is obtained as compared with the case where the scanning directions in FIG. 2 are different.

  In the case of black-and-white copying, the reproduction is performed with the density of black toner only, but the relationship between white and black is not absolute because it can be reversed by the processing on the copying apparatus side, and is in the same forgery prevention medium. Only the pattern relationship is essential. In the case of color copy, colors other than white are reproduced by subtractive color mixture using four colors of toner including three colors of yellow, magenta, and cyan, or black, but the light-dark relationship for each separation color is a monochrome copy. Are reproduced with the same light and shade relationship, and their combined color determines the color tone of the copy. Therefore, different copies can be obtained depending on the scanning direction of the copying machine and the installation direction of the anti-counterfeit medium, as in the case of monochrome copying, and it is easily found that the copy is different from the original anti-counterfeit medium. To do.

  Further, as shown in FIG. 4, the liquid crystal layer may be aligned in the triaxial directions of 0 ° direction 51, 45 ° direction 52, and 90 ° direction 53. Further, the liquid crystal layer 54 having an insufficient curing degree and the liquid crystal layer 55 having an adequate curing degree may be provided in the same plane. When these liquid crystal layers are subjected to heat shrinkage, microcracks are formed in the 54 portion along different alignment directions in the respective regions 51 and 53, but the 55 portion has heat resistance. Even if a different orientation state occurs in each of the regions 51 and 52, a microcrack does not occur. When the uniform reflective layer 4 is provided on the liquid crystal layer as the optical functional layer, the liquid crystal layer 54 having an insufficient degree of curing as shown in FIG. Since the directions of the scattered light and the specular reflected light change depending on the direction of the crack, the pattern recognizable portion 11 in which the characters can be visually observed is obtained. However, since the liquid crystal layer 55 having a sufficient degree of curing is not cracked, the reflected light is uniformly returned, resulting in the pattern unrecognizable portion 12 where characters are not visible.

  Further, when the anti-counterfeit medium shown in FIG. 4 is copied, it is copied as shown in FIG. 7 or FIG. In each of the liquid crystal layers, the portion corresponding to the liquid crystal layer 54 having an insufficient degree of curing becomes a different copy, such as the pattern display unit (1) 16 or the pattern display unit (2) 18, and the degree of cure is The portion corresponding to the liquid crystal layer 55 that is sufficient is a homogeneous copy portion such as the pattern non-display portions 17 and 19.

  Further, when the anti-counterfeit medium shown in FIG. 4 is turned upside down and confirmed from the transparent support base 3 side by a verification machine having a polarizer 13, it looks like FIG. The back pattern recognizable portion 14 corresponding to the liquid crystal layer 54 having an insufficient degree of curing is formed by the difference between the scattered light and the specular reflected light from the back side of the microcrack in the light and shade depending on the alignment direction of the liquid crystal layer and the direction of rotation of the polarizer. Although contrast is added and the appearance is different from the pattern recognizable portion 11 shown in FIG. 5 as viewed from the front side, recognition can be performed at substantially the same level. On the other hand, in the partial back pattern recognizable portion 15 corresponding to the liquid crystal layer 55 having a sufficient degree of cure, the characters are not visible when viewed through the polarizer 13 as in the case of the pattern unrecognizable portion 12 in FIG. Although the pattern cannot be recognized, a character pattern is recognized in the portion observed through the polarizer 13 by the shading depending on the alignment direction of the liquid crystal layer and the rotation direction of the polarizer.

The anti-counterfeit medium of the present invention has a copy prevention function, an overt function and a cover function, and is a high-security anti-counterfeit medium, so it is used to prevent forgery of securities, branded products, certificates, etc. It is most suitable for use on printed labels, transfer foils, and anti-counterfeit papers. In addition, since the anti-counterfeit medium can be easily manufactured in a relatively short process, it is possible to provide a low-cost and highly reliable adhesive label and transfer foil processed using the medium.

FIG. 9 is a schematic cross-sectional view of an adhesive label using the anti-counterfeit medium of the present invention.
An adhesive layer 22 supported by a release paper 21 is provided on one side of the anti-counterfeit medium, in this example, on the back side of the support base 3. The release paper 21 and the adhesive layer 22 can be the same as those used for general adhesive labels or pressure-sensitive adhesive labels, and can be adhered by peeling the release paper to the adherend and pressing the adhesive layer surface. Here, the adhesive layer includes a function capable of repeatedly using sticking and peeling as a so-called adhesive layer. Since the anti-counterfeit medium of the present invention can be manufactured relatively easily in a short process, a highly practical adhesive label is easily provided by pasting the adhesive layer previously applied on the release paper with the anti-counterfeit medium of the present invention. be able to.

  The adhesive label can be a label that is easier to use by providing notches and / or perforations in the anti-counterfeit medium that has been bonded. Although not shown, by providing notches and perforations in accordance with the pattern display units provided on the forgery prevention medium, the release paper 21 of the adhesive label is peeled off and the adhesive layer 22 surface is pressed against the adherend. At this time, the necessary region can be limited and bonded along the notch or perforation. It is easy to add a general process for continuously forming notches and perforations to the manufacturing process of the anti-counterfeit medium of the present invention in advance, and to easily provide a highly practical adhesive label. Can do.

FIG. 10 is a schematic cross-sectional view of a transfer foil using the anti-counterfeit medium of the present invention.
A peeling layer 23 is provided between the support material 3 of the anti-counterfeit medium and the optical functional layers 1 and 2, and an adhesive layer 22 is provided on the reflective layer 4 of the anti-counterfeit medium. Further, a release paper 21 may be provided on the adhesive layer 22. The release paper 21 and the adhesive layer 22 can be the same as those used for general adhesive labels or adhesive labels. The anti-counterfeit medium peeled off the release paper 21 and bonded to the adherend is bonded with the reflective layer 4 facing down in the opposite direction, and the optical functional layers 1 and 2 are located on the surface side. The support substrate 3 can be peeled off from the release layer 23 at the time of transfer or after transfer. Further, the release layer 23 also serves as a surface protective layer after the support substrate 3 is peeled off.

  In order to produce the transfer foil of this example, the release layer 23 is applied prior to forming the optical functional layers 1 and 2 on the support base 3. The release layer can be coated with a general silicone resin material using a known method such as a gravure coating method or a micro gravure coating method. Next, the optical functional layers 1 and 2 are formed by the above-described means, and the reflective layer 4 is further formed by physical vapor deposition. Then, the process of adhere | attaching the transfer foil obtained by apply | coating the contact bonding layer 22 continuously to a to-be-adhered body can also be processed continuously. The above process is suitable for a web roll-to-roll continuous process using a film, and mass production is also possible. Further, when the transfer foil is temporarily stored and not used immediately after manufacture, it is better to wind the adhesive layer 22 together with the release paper 21 on an anti-counterfeit medium.

Examples of the present invention will be described below.
A biaxially stretched polyester film Lumirror 25T60 (manufactured by Toray Industries, Inc.) was used as the supporting substrate 3, and IA-01 (manufactured by DIC Corporation) as a photo-alignment agent was applied by microgravure to form a film. This photo-alignment agent is a material having a liquid crystal alignment force in the polarization direction when irradiated with 365 nm polarized light. The photo-alignment film is irradiated with ² J / cm ^{2 on} the entire surface using polarized ultraviolet rays, and then a photomask is prepared and only a specific pattern portion is irradiated with polarized light by 90 ° with respect to the polarization direction of the entire surface irradiation. This was performed at an irradiation amount of ² J / cm ^{2 in} the polarization direction with an angle difference of ² J / cm ² .

Thereafter, UV curable liquid crystal UCL-008 manufactured by DIC Corporation was applied by microgravure, UV curing was performed in air at an irradiation amount of 100 mJ / cm ² , and region 1 of the optical functional layer using the liquid crystal layer was obtained. 2 was obtained. Furthermore, a film of metal Al was formed by a vacuum deposition method. By using the vacuum vapor deposition method, the liquid crystal layer is heated during the vapor deposition, so that the liquid crystal layer undergoes thermal shrinkage and regular microcracks are formed along the alignment direction, and Al is formed there.

  As a result of visually confirming the anti-counterfeit medium thus manufactured, the brightness of the region 1 of the optical functional layer 1 and the region 2 of the optical functional layer were different depending on the viewing angle. Further, when copying was attempted with a copying machine, FIG. 2 and FIG. 3 became as shown in FIG. 3, and an image close to a real visual image of the product of the present invention was not obtained.

A biaxially stretched polyester film Lumirror 25T60 (manufactured by Toray Industries, Inc.) was used as the supporting substrate 3, and IA-01 (manufactured by DIC Corporation) as a photo-alignment agent was applied by microgravure to form a film. This photo-alignment agent is a material having a liquid crystal alignment force in the polarization direction when irradiated with 365 nm polarized light. The surface of the photo-alignment film is irradiated with polarized ultraviolet rays at ² J / cm ² , and then light is transmitted through only 52 portions in a direction at an angle of 45 ° with respect to the polarization direction irradiated on the entire surface. A photomask was prepared and irradiated at a pattern of ² J / cm ² . Further, a photomask that allows light to pass through only 53 portions in a direction with an angle difference of 90 ° was prepared and irradiated with ² J / cm ² in a pattern.

Thereafter, UV curable liquid crystal UCL-008 manufactured by DIC Corporation was applied by microgravure, and 54 m was irradiated with 10 mJ / cm ² of UV under a nitrogen atmosphere, and 55 was irradiated with 300 mJ / cm ² of UV. . Furthermore, a film of metal Al was formed by a vacuum deposition method. By using the vacuum vapor deposition method, the liquid crystal layer is heated during the vapor deposition, so that the liquid crystal layer 54 undergoes thermal contraction to form regular microcracks along the alignment direction, and Al is formed there. In addition, since the liquid crystal layer 55 having a sufficient degree of curing had heat resistance, no cracks were formed along the alignment direction, and Al was uniformly formed.

  When the anti-counterfeit medium produced in this manner is visually confirmed, the portion of the liquid crystal layer 54 that is confirmed as shown in FIG. It looked like a character pattern with different brightness. Furthermore, when it confirmed with the verification machine from the support base material side, the image like FIG. 6 was recognized. Further, when copying was attempted with a copying machine, FIG. 7 and FIG. 8 became as shown in FIG. 8, and an image close to the real visual image of the product of the present invention was not obtained.

1... One region of optical functional layer having optical anisotropy in a certain direction 2... One region of optical functional layer having optical anisotropy in a certain direction different from 1. Base material 4 ··· Reflective layer 5 ··· White portion of the copy (bright portion)
6 ... Black part (dark part) of copied material
DESCRIPTION OF SYMBOLS 10 ... Counterfeit prevention medium 11 ... Pattern recognizable part 12 ... Pattern recognizable part 13 ... Polarizer 14 ... Back pattern recognizable part 15 ... Partial back pattern recognizable part 16 ... pattern display part (1)
17, 19 ... Pattern non-display part 18 ... Pattern display part (2)
21 ... Release paper 22 ... Adhesive layer 23 ... Release layer 51 ... Aligned liquid crystal layer 52 ... 51 ° Different from the liquid crystal layer 53 ... 51 different in orientation direction 90 ° Liquid crystal layer 54 with different orientation direction ... Liquid crystal layer 55 with insufficient cure degree ... Liquid crystal layer with sufficient cure degree

Claims (7)

An anti-counterfeit medium having an optical functional layer patterned on a support substrate and a reflective layer in this order, wherein the optical functional layer has optical anisotropy formed by a plurality of microcracks in a certain direction. made from a plurality of regions having different alignment directions from each other, a plurality of micro-cracks in the certain direction is entered along the orientation direction of the optical functional layer in the layer plane, in the plurality of areas, the alignment of the microcracks An anti-counterfeit medium characterized in that the intensity ratio of scattered light and specular reflected light changes in accordance with the light projection direction with respect to the direction.   2. The medium for preventing forgery according to claim 1, wherein the optical functional layer is made of liquid crystal molecules.   The optical functional layer is oriented in different directions of 0 °, 45 °, and 90 °, and the oriented optical functional layer in the layer surface has a microcracked portion along the orientation direction and a microcrack. The forgery prevention medium according to claim 1, further comprising: a non-counterfeit portion. It is a manufacturing method which manufactures the forgery prevention medium in any one of Claims 1-3, Comprising: After pattern-forming the optical function layer which has an incompletely hardened part on a support base material, a reflective layer is formed by a physical vapor deposition method. A method for producing a forgery-preventing medium, comprising forming a plurality of microcracks along the orientation direction of the optical functional layer in the layer plane in the incompletely cured optical functional layer of the base by forming a film.   An adhesive label comprising an adhesive layer supported by a release paper on one side of the anti-counterfeit medium according to claim 1.   6. The adhesive label according to claim 5, wherein the anti-counterfeit medium is provided with notches and / or perforations.   A release layer is provided between the support base material of the anti-counterfeit medium according to any one of claims 1 to 3 and the optical functional layer, and an adhesive layer is provided on the reflective layer of the anti-counterfeit medium. Transfer foil.

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