JP2006142576A - Medium for judging authenticity, label of medium for judging authenticity, transfer sheet of medium for judging authenticity and sheet and information recording body enabling judgment of authenticity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium for judging authenticity which further complicates the variation of a seen color of a cholesteric liquid crystal layer as the medium for judging authenticity, according to an angle of view, and which has a high durability to forgery and alteration. <P>SOLUTION: The medium has a constitution wherein a transparent base 3 and a prism layer 4 are stacked sequentially at the back of the cholesteric liquid crystal layer 2 and further a black layer 6 is stacked at the back. In the prism layer 4 by which the cholesteric liquid crystal layer 2 is accompanied at the back, the light incident thereon from the direction of a normal line is retroreflected and returns to the original direction. Therefore another color consequent on the retroreflection is added to the variation of the color of the cholesteric liquid crystal layer 2 alone and thus the color variation is further complicated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is difficult to tamper with and is suitable for judging authenticity, a medium for authenticity determination, a medium label for authenticity determination, a medium transfer sheet for authenticity determination, a sheet capable of authenticity determination, and authenticity determination Related to an information recording medium.

  For example, high-priced products with high economic value, credit cards that can generate value when used as ID means, or vouchers, etc. are provided with means for proving their authenticity (or for determining authenticity). There are many. As a typical means for proving authenticity, many labels using holograms and diffraction gratings are used, but those having special visual effects other than these are also used. However, when new things appear as a means to prove authenticity, some people try to forge or alter with an unfair intention, so the side that creates means to prove authenticity is constantly new. It is necessary to produce.

As a means of proving authenticity that has been published recently, the authenticity judgment consists of a laminated structure in which each layer of a release layer / protective layer, a cholesteric liquid crystal layer, a tint block printing layer, and an adhesive layer is sequentially laminated on a base film. There is a body transfer foil (Patent Document 1).
JP 2004-50596 A (Claim 1).

  Using the transfer foil for authenticity determination body described in Patent Document 1, when transfer is performed on an adherend that needs to be verified, an adhesive layer, a tint block printing layer, and a cholesteric layer are formed on the adherend. A liquid crystal layer and a release layer / protective layer are sequentially laminated. In addition to the complexity of the tint block printing layer, the one obtained by the transfer has an effect of causing a color change with selective reflectivity depending on the viewing angle, which the cholesteric liquid crystal layer has.

  FIG. 6 is a diagram for explaining the function of the cholesteric liquid crystal layer in the authenticity determination medium having the cholesteric liquid crystal layer. As shown in FIG. 6A, when a black layer (or a dark color layer whose color is close to black) 106 is laminated on the back surface of the cholesteric liquid crystal layer 102, in the normal direction of the cholesteric liquid crystal layer 102, for example, Green is observed, and blue is observed from an oblique direction. Further, as shown in FIG. 6B, when the white layer 106 ′ is laminated on the back surface of the cholesteric liquid crystal layer 102, light red is observed both in the normal direction and in the oblique direction of the cholesteric liquid crystal layer 102. Is done.

  Therefore, the cholesteric liquid crystal layer having different colors depending on the viewing angle as described above has anti-counterfeiting properties because it is difficult to reproduce the same appearance by simple color copying or the like. However, the cholesteric liquid crystal itself is already known. By analyzing the intrinsic material and creating the same layer, it is possible to make the color change caused by the viewing angle the same as that of the intrinsic material. is there.

  In the present invention, as described above, it is an object to further complicate the color change depending on the viewing angle, which is indicated by the applied cholesteric liquid crystal layer.

  The inventor, in addition to the color change depending on the viewing angle indicated by the cholesteric liquid crystal layer, for example, by arranging a prism sheet having an uneven surface with a plurality of triangular prisms arranged on the back as the base of the cholesteric liquid crystal layer, in particular, The inventors have found that it is possible to change the color observed when observed from the front, and have reached the present invention.

  The first invention is characterized in that a prism sheet having a concavo-convex shape in which grooves having V-shaped cross sections are arranged on the back surface of the transparent layer is laminated on the back surface of the color variable layer having different colors depending on the viewing angle. The present invention relates to an authenticity determination medium.

  A second invention relates to the medium for authenticity determination according to the first invention, wherein the V-shaped groove of the prism sheet has a filling layer filled in a pattern with a transparent substance. Is.

  A third invention relates to a medium for authenticity determination according to the first or second invention, wherein a black layer or a dark color layer is laminated on a back surface of the prism sheet.

  A fourth invention relates to a medium label for authenticity determination, wherein an adhesive layer is further laminated on the back surface of the medium for authenticity determination of any one of the first to third inventions.

  5th invention is related with the medium transfer sheet for authenticity determination characterized by the fact that the authenticity determination medium of any one of the 1st-3rd invention is laminated | stacked on the peelable surface of the peelable base material. is there.

  A sixth invention relates to a sheet capable of authenticity determination, characterized by having the authenticity determination medium of any one of the first to third inventions visible in a part of the sheet.

  In the seventh invention, the authenticity determination medium according to any one of the first to third inventions is laminated on the surface of the information recording body which is the object of authenticity determination, or is visible on a part of the information recording body. The present invention relates to an information recording body capable of authenticity determination.

  According to the first invention, the prism sheet provided on the back surface exhibits retroreflectivity in the normal direction and translucency in the oblique direction, so that the color that can be seen depending on the viewing angle is greater than in the case of the conventional color change layer. It is possible to provide a medium for true / false determination that changes more complicatedly.

  According to the second invention, there is provided a medium for authenticity determination in which the effect of the first invention occurs in a portion without a filling layer, and the effect of a color change layer occurs in a portion with a filling layer. Can do.

  According to the third invention, in addition to the effects of the first or second invention, there is provided an authenticity determination medium in which the color of the reflected light can be clearly confirmed by the black layer or the dark color layer disposed on the back surface. can do.

  According to the fourth invention, since the adhesive layer is laminated on the back surface of the medium for authenticity determination having the effects of any one of the first to third inventions, it can be applied to other articles as it is. An easy label for attaching a medium for authenticity determination can be provided.

  According to the fifth invention, since the peelable sheet is laminated on the authenticity determination medium having the effects of any one of the first to third inventions, the truth that can be easily applied to other articles by transfer. A fake determination medium transfer sheet can be provided.

  According to the sixth invention, since the authenticity determination medium having the effects of any one of the first to third inventions is applied, the authenticity of the information added to the sheet can be easily determined. A sheet that can be determined can be provided.

  According to the seventh invention, since the medium for authenticity determination having the effect of any one of the first to third inventions is applied to the information recording medium, the authenticity determination that enables the authenticity determination of itself Possible information recording bodies can be provided.

  FIG. 1 is a diagram illustrating the basic structure of the authenticity determination medium 1 of the present invention and the color change depending on the angle. The medium for authenticity determination 1 has a cholesteric liquid crystal layer 2 as a color variable layer whose color varies depending on the viewing angle, and a transparent base material 3 is laminated on the back surface, and the transparent base material 3 is laminated on the back surface. A prism sheet 5 is formed together with the prism layer 4, and a black layer 6 is laminated on the back surface of the prism layer 4. In the figure, the upper surface side is the observation side, and the lower surface side is the back side. Here, the prism layer 4 has a concave-convex shape in which grooves having a V-shaped cross section are arranged, but it can also be said that a prismatic body having a triangular cross section is arranged.

  Light incident on the cholesteric liquid crystal layer 2 of the authenticity determination medium 1 having such a configuration from the normal direction on the observation side is transmitted through the cholesteric liquid crystal layer 2 and changed in direction by the prism layer 4 of the prism sheet 5. This causes a so-called “retroreflection” to return to the original direction. Even if the incident light slightly deviates from the normal direction, if the total reflection condition is satisfied on two sides that are not parallel to the transparent substrate 5 among the sides of the individual triangles constituting the cross section of the prism layer 4, The reflected light returns in the incident direction. Thus, the strong reflected light returning in the incident direction exhibits, for example, a light red color.

  In the case where the incident direction of light from the observation side is deviated from the normal direction and the above-described total reflection condition is not satisfied, the light incident on the prism layer 4 does not cause retroreflection, and exits from the back surface to cause the black layer 6. To be absorbed. In this case, the effect of different colors depending on the viewing angle based on the properties of the cholesteric liquid crystal layer 2 becomes clear. Therefore, by changing the viewing angle, for example, from the direction close to the normal direction to the direction far from the normal direction. A color change from green to blue is observed.

  Therefore, in the authenticity determination medium 1, if the prism sheet 5 is not accompanied, for example, only a color change from green to blue can be seen. ~ Green-blue color change is seen and it is more complicated.

  FIG. 2 is a diagram illustrating a basic structure of another authenticity determination medium 1 ′ of the present invention and a color change depending on an angle. This authenticity determination medium 1 ′ is described with reference to FIG. 1 except that the left half of the irregularities of the prism layer 4 in the drawing is filled with the filling layer 7. Like the authenticity determination medium 1, the cholesteric liquid crystal layer 2, the transparent substrate 3, and the prism sheet 5 formed by laminating the prism layer 4 on the back surface of the transparent substrate 3 are sequentially laminated.

  The filling layer 7 in the medium for authenticity determination 1 ′ is made of a transparent material having the same refractive index as that of the light constituting the prism layer 4 or having a very close refractive index of light. It is preferable. In such a portion filled with the filling layer 7, even if the incident light is from the normal direction on the observation side, the light incident on the prism layer 4 is absorbed by the black layer 6 through the filling layer 7. The same applies to incident light from other than the normal direction.

  Of the unevenness of the prism layer 4 of the medium for authenticity determination 1 ′, the right half in the drawing is not filled with the filling layer 7. Therefore, the right half in which the prism layer 4 of the authenticity determination medium 1 ′ is not filled with the filling layer 7 is the same as the authenticity determination medium 1 described with reference to FIG. 1.

  Therefore, in the medium for authenticity determination 1 ′, in the right half without the packed layer 7, as in the medium for authenticity determination 1 described with reference to FIG. A change is seen, and a green-blue color change is seen in the left half with the filling layer 7.

  In the authenticity determination medium 1 ′ in which the filler layer 7 is filled in a part of the prism layer 4, the filler layer 7 can be provided in a predetermined pattern. In that case, the filler layer as described above is used. The visual effect due to the presence or absence of 7 can be generated in a pattern.

  The cholesteric liquid crystal layer 2 is constituted by using cholesteric liquid crystal as a material, or using nematic liquid crystal and a chiral agent, and is formed by applying a solvent solution of these materials by various coating methods and drying. Alternatively, an ultraviolet polymerizable composition is prepared using a polymerizable material as a raw material, the obtained ultraviolet polymerizable composition is applied by various coating methods, and after drying, it is irradiated with ultraviolet rays to be polymerized. It can also be formed.

  When the cholesteric liquid crystal layer 2 is formed, the transparent substrate 3 described above may be used as an application target. The cholesteric liquid crystal layer 2 may be formed on a transparent substrate different from the transparent substrate 3.

  As the transparent substrate 3, a material having solvent resistance and heat resistance that can withstand the lamination of the cholesteric liquid crystal layer 2, the prism layer 4 or the filling layer 7 described later, or other processing is preferable. Since it depends on the purpose of use, it is not limited, but a film-like or sheet-like plastic is preferable. For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, and polyethylene / vinyl alcohol can be exemplified. .

  Since the cholesteric liquid crystal layer 2 is preferably aligned, it is preferable that an alignment film is stacked on the transparent substrate 3 on the side where the cholesteric liquid crystal layer 2 is stacked. The alignment film may be formed of any material as long as it can be generally used as an alignment film, such as polyvinyl alcohol resin (PVA) or polyimide resin. A solvent solution of these resins may be applied to the surface of the application target as described above by an appropriate coating method and dried, followed by rubbing with a cloth, a brush, or the like to form an alignment film. it can. Note that when a stretched plastic sheet is used as a lamination target of the cholesteric liquid crystal layer 2 such as the transparent substrate 3, the surface originally has orientation, so that the lamination of the alignment film can be omitted.

  In FIG. 1 and FIG. 2, the cross-sectional shape of the prism layer 4 is drawn assuming an isosceles triangle in which the lengths of two sides other than being in contact with the transparent substrate 3 are equal, but the cross-sectional shape is an equilateral triangle. Any triangle such as a right triangle (including an isosceles triangle) may be used. Alternatively, other than a triangular prism can be used as long as the retroreflective property and the incident light transmittance are switched depending on the incident angle. For example, a lenticular lens (kamaboko lens) may be arranged. In addition, a large number of minute lenses may be densely arranged. When the cross section of the prism layer 4 is triangular, the thickness of the prism layer is about 1 μm to 100 μm, more preferably about 5 μm to 25 μm, and the pitch depends on the cross sectional shape of the prism. It is about the same or about a few times to several times.

In order to provide the unevenness of the prism layer 4, a mold having a reverse shape of a predetermined shape on the surface is prepared, and a transparent ultraviolet ray is placed between the mold and the transparent substrate 3 that is spaced from the mold. It is possible to obtain a laminate in which a prism layer 4 having predetermined irregularities is laminated on a transparent substrate 3 by filling a curable resin composition or the like on one side, curing it by ultraviolet irradiation or the like, and then removing the mold. it can. In the case where the transparent base material 3 and the prism layer 4 are manufactured as a single unit, not as separate layers,
A material that can be molded is selected and used as the transparent substrate 3, and the transparent substrate 12 is thermally deformed by sandwiching the transparent substrate 3 between a flat plate and a template having a reverse shape of a predetermined shape on the surface. It can be obtained by applying pressure while heating to temperature and then releasing. Or it can also shape | mold continuously using a roller-shaped type | mold and a backup roller.

  The filling layer 7 is preferably a patterned layer in which the unevenness of the prism layer 4 is flattened by filling the unevenness, and has the same refractive index as the light constituting the prism layer 4. Or is preferably made of a material having a refractive index of light that is very close, and from the necessity of forming a layer having a thickness necessary for leveling unevenness, such as a silk screen printing method, It is preferable to form by a method capable of increasing the size.

  The black layer 6 functions to absorb light reaching the back surface of the prism layer 4 from the observation side, and is a layer colored using a black colorant, preferably a black pigment such as carbon. In particular, paper or a sheet-like material such as a plastic film is applied with a black paint containing a black colorant, or black paper manufactured using a material containing a black colorant as a raw material or It is a black plastic film. The black layer 6 may be laminated by pasting a pre-made one on the back surface of the prism layer 4 or may be obtained by forming a sheet-like material for the back surface of the prism layer 4.

  The authenticity determination medium 1 or 1 ′ of the present invention is highly valuable when applied to the high-priced products, credit cards, and vouchers mentioned in the description of the background art. For the purpose of facilitating application to the target article, as described below, it is preferable to process and use it in the form of a label or transfer sheet.

  FIG. 3 is a diagram showing a true / false determination medium processed into a label. As shown in FIG. 3, the authenticity determination medium label 11 of the present invention is obtained by laminating an adhesive layer 8 on the back surface of the black layer 6 of the authenticity determination medium 1 ′ described with reference to FIG. . Thus, by laminating the adhesive layer 8 on the back surface, it becomes easy to affix to the adherend. The adhesive layer 8 may be composed of either a heat-sensitive adhesive or a pressure-sensitive adhesive. When the adhesive layer 8 is configured using a pressure-sensitive adhesive, a peelable sheet may be temporarily attached to the exposed surface of the pressure-sensitive adhesive layer, and the peelable sheet may be peeled off each time it is used. Of course, the authenticity determination medium 1 ′ used here may be replaced with the authenticity determination medium 1.

  FIG. 4 is a diagram showing a medium for authenticity determination processed into a transfer sheet. As shown in FIG. 4, the authenticity determination medium transfer sheet 12 of the present invention is formed by laminating an adhesive layer 8 on the back surface of the black layer 6 of the authenticity determination medium 1 ′ described with reference to FIG. And the observation side is laminated | stacked on the peelable surface 14 of the peelable base material 13. FIG. In addition to being easy to affix to the adherend using the adhesive layer 8 on the back surface, the transfer sheet in the form of a transfer sheet is determined by each continuous peelable substrate 13 for authenticity determination. Since the working medium 1 can be supported, it is suitable for applying the authenticity judging medium 1 by supplying adherends one by one. If an adhesive can be applied to each adherend during transfer, the adhesive layer 8 in the authenticity determination medium transfer sheet 12 can be omitted. After the transfer is completed, the peelable substrate 13 is peeled off and removed. Of course, the authenticity determination medium 1 ′ used here may be replaced with the authenticity determination medium 1, as in the case of the label.

  Since the medium for authenticity determination 1 or 1 ′ according to the present invention has durability against forgery / alteration, it can be applied to improve the durability against forgery / alteration of the adherend. FIG. 5 shows a sheet 15 capable of authenticity determination, in which the authenticity determination medium 1 or 1 'is pasted on the sheet 16 as an adherend. Since the authenticity-determinable sheet 15 can guarantee authenticity even in a blank sheet state, the authenticity of the sheet having information can be ensured by applying information by any method. Can do.

  Here, the sheet 16 may have various materials and uses. As a material of the base material 16, paper, plastic, metal foil, cloth, non-woven fabric, etc., or any complex thereof can be used.

  Note that the place where the authenticity determination medium 1 or 1 ′ is applied to the sheet 16 is not limited to the observation side surface of the sheet 16, and may be either the front or back of the sheet 16 or both. When the sheet has a laminated structure of two or more material sheets, at least the observation side sheet is configured to be transparent and the others are left opaque, and are laminated between the observation side transparent sheet and the back side opaque sheet. be able to. Alternatively, a hole is formed in the observation-side sheet of the two sheets, and the authenticity determination medium 1 or 1 ′ is applied between the two sheets, so that the authenticity determination medium is inserted from the hole in the observation-side sheet. 1 or 1 ′ may be seen, and it is only necessary that a part of the sheet 16 has a medium for authenticity determination so as to be visible.

  The sheet 16 made of the material as described above may be an information recording body created by applying information such as a character, a color pattern such as a monetary amount, an issuing company name, or a cautionary note by means of printing or the like. The authenticity-determinable sheet 15 configured by using such an information recording body 16 is also an authenticity-determinable information recording body that can be used as a gold ticket, a transportation ticket, a commuter pass, or the like. The information recording body 16 may be provided with a recording means capable of performing electromagnetic recording, such as a magnetic recording layer or an IC chip, and an information recording capable of determining authenticity constituted by using such an information recording body 16. The body has a high utility value as a credit card, a deposit / save card for a financial institution, and the like.

It is a figure explaining the laminated structure and function of the medium for authenticity determination of this invention. It is a figure explaining the laminated structure of another authenticity determination medium of this invention, and a function. It is a figure which shows what made the authenticity determination medium into the label form. It is a figure which shows what used the medium for authenticity determination in the shape of a transfer sheet. It is a figure which shows the sheet | seat which can authenticate authenticity which applied the authenticity determination medium. It is a figure which shows the medium for authenticity determination using the conventional cholesteric liquid crystal layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Medium for authenticity determination 2 ... Cholesteric liquid crystal 3 ... Transparent base material 4 ... Prisma layer 5 ... Prism sheet 6 ... Black layer 7 ... Filling layer 8 ... Adhesive layer 11 ... Authenticity Judgment medium label 12 ... Authenticity judgment medium transfer sheet 13 ... Releasable substrate 15 ... Authentic sheet

Claims (7)

  A medium for authenticity determination, characterized in that a prism sheet having a concavo-convex shape in which grooves having V-shaped cross-sections are arranged on the back surface of the transparent layer is laminated on the back surface of the color variable layer having different colors depending on the viewing angle. .   2. The medium for authenticity determination according to claim 1, wherein the V-shaped groove of the prism sheet has a filling layer filled in a pattern with a transparent substance.   The authenticity determination medium according to claim 1, wherein a black layer or a dark color layer is laminated on a back surface of the prism sheet.   An authenticity determination medium label, wherein an adhesive layer is further laminated on the back surface of the authenticity determination medium according to any one of claims 1 to 3.   4. A medium transfer sheet for authenticity determination, wherein the medium for authenticity determination according to claim 1 is laminated on a peelable surface of a peelable substrate.   A sheet capable of authenticity determination, comprising the medium for authenticity determination according to any one of claims 1 to 3 so as to be visible in a part of the sheet. The authenticity determination medium according to any one of claims 1 to 3 is laminated on a surface of an information recording body that is an object of authenticity determination, or is visible on a part of the information recording body. An information recording medium that can determine whether the feature is true or false.

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