JP5070774B2 - Authenticity indicator - Google Patents

Description

  The present invention relates to an authenticity display body that displays authenticity of an article or the like.

  Conventionally, as one of measures to prevent counterfeiting of cards, passports, identification cards, gift certificates, etc., and counterfeit goods, pirated goods, etc., an authenticity display body (identification medium) that displays the authenticity of articles etc. Affixing to an object is performed. That is, by determining the authenticity of the authenticity display body, the authenticity of the object to which the authenticity display body is attached is determined. Therefore, the authenticity indicator is difficult to be counterfeited, and the authenticity of the authenticity indicator itself must be determined accurately.

  As such an authentic display, there is a hologram label using a relief hologram. However, this type of hologram has been developed in recent years due to the advancement of counterfeiting technology and the availability of hologram materials. There is a risk of being overlooked.

  In addition, a cholesteric liquid crystal that has polarization selectivity and wavelength selectivity and whose reflected color changes depending on the viewing angle is also used as an authentic display. However, in recent years, forgery techniques have also become more sophisticated, and even an authentic display using cholesteric liquid crystals may be forged.

Further, Japanese Patent No. 36552487 discloses an identification medium (authentic display) having a relief hologram layer and a cholesteric liquid crystal layer.
Japanese Patent No. 3655287

  However, in the identification medium disclosed in Japanese Patent No. 36552487, the cholesteric liquid crystal layer has only a function as a reflection layer for reflecting incident light to the relief hologram layer. The authenticity of the identification medium is determined only by the relief hologram image. Further, as described above, relief holograms are beginning to be forged. In view of these facts, this identification medium is troublesome to produce, but can only have an authenticity determination function and an anti-counterfeit effect equivalent to those of the above-described single relief hologram or single cholesteric liquid crystal.

  The present invention has been made in view of such points, and is to provide an authentic display that is difficult to forge and has high discrimination.

  An authentic display according to the present invention is a sheet-like authentic display that can be judged by observing reflected light, and has a cholesteric regular liquid crystal structure and a specific light. A reflection layer including a reflection portion for reflecting the light and a diffraction layer made of a volume hologram and diffracting specific light.

  According to the authenticity display of the present invention, it is possible to more accurately authenticate using the function of the reflective layer capable of reflecting only specific light and the function of the diffraction layer capable of diffracting only specific light. Can be determined. In addition, since special equipment and materials are required for the production of the volume hologram, it is difficult to reproduce the authentic display. For these reasons, the authenticity display according to the present invention has an excellent authenticity display function and a high anti-counterfeiting effect.

  In the authentic display according to the present invention, the wavelength region of the specific light reflected by the reflective layer and the wavelength region of the specific light diffracted by the diffraction layer may overlap at least partially. Good. According to such an authentic display, it is possible to visually recognize both the light reflected by the reflective layer and the light diffracted by the diffraction layer. Then, by holding the circular deflecting plate, only the light diffracted by the diffraction layer can be clearly seen. Therefore, authenticity can be determined easily and more accurately. In addition, since the wavelength region reflected by the reflective layer and the wavelength region diffracted by the diffraction layer overlap, the light reflected by the reflective layer in a state where the light diffracted by the diffraction layer can be visually recognized. Can also be visually recognized. Therefore, when a volume hologram is forged using this authentic display as an original, light reflected by the reflective layer is also recorded in the forged product. For this reason, such a counterfeit product can be easily and reliably determined to be a counterfeit product by a determination method using, for example, a circularly polarizing plate, in addition to visual determination. That is, according to such an authenticity display body, it is possible to make it extremely difficult to produce a counterfeit product.

  In the authenticity display according to the present invention, either one of the wavelength range of the specific light reflected by the reflective layer and the wavelength range of the specific light diffracted by the diffraction layer is included in the other. You may do it. According to such an authentic display, it is possible to visually recognize both the light reflected by the reflective layer and the light diffracted by the diffraction layer. Then, by holding the circular deflecting plate, only the light diffracted by the diffraction layer can be clearly seen. Therefore, authenticity can be determined easily and more accurately. In addition, since the wavelength region reflected by the reflective layer and the wavelength region diffracted by the diffraction layer overlap, the light reflected by the reflective layer in a state where the light diffracted by the diffraction layer can be visually recognized. Can also be visually recognized. Therefore, when a volume hologram is forged using this authentic display as an original, light reflected by the reflective layer is also recorded in the forged product. For this reason, such a counterfeit product can be easily and reliably determined to be a counterfeit product by a determination method using, for example, a circularly polarizing plate, in addition to visual determination. That is, according to such an authenticity display body, it is possible to make it extremely difficult to produce a counterfeit product.

  Further, in the authentic display according to the present invention, a wavelength region having a light quantity more than half of the maximum light quantity in the light quantity distribution with respect to the wavelength of the light reflected by the reflective layer, and the light diffracted by the diffraction layer. Any one of the wavelength regions that have a light quantity that is more than half of the maximum light quantity in the light quantity distribution with respect to the wavelength may be included in the other. That is, any one of the wavelength region corresponding to the half width of the reflective layer and the wavelength region corresponding to the half width of the diffraction layer may be included in the other. According to such an authentic display, both the light reflected by the reflection layer and the light diffracted by the diffraction layer can be visually recognized more clearly. Then, by holding the circular deflecting plate, only the light diffracted by the diffraction layer can be clearly seen. Therefore, authenticity can be determined more accurately. Such an authenticity display body is extremely excellent not only from the viewpoint of authenticity discrimination but also from the viewpoint of preventing counterfeit products. That is, according to such an authentic display, the wavelength region reflected with a high reflectance among the wavelength regions reflected by the reflective layer and the diffraction region with a high diffraction efficiency among the wavelength regions diffracted by the diffraction layer are diffracted. Overlap with the wavelength region. Therefore, in a state where the light diffracted by the diffraction layer can be clearly seen, the light reflected by the reflection layer can also be clearly seen. For this reason, when a volume hologram is forged using this authentic display as an original, light reflected by the reflective layer is also recorded in the forged product. Such a counterfeit product can be easily and reliably determined as a counterfeit product by a determination method using, for example, a circularly polarizing plate, in addition to visual determination. That is, according to such an authenticity display body, it is possible to make it extremely difficult to produce a counterfeit product.

  Furthermore, in the authentic display according to the present invention, the wavelength (selected center wavelength) having the maximum light amount in the light amount distribution with respect to the wavelength of light reflected by the reflective layer is the wavelength of light diffracted by the diffraction layer. The wavelength may be longer than the wavelength (selected center wavelength) that has the maximum light amount in the light amount distribution with respect to. In general, a cholesteric regular liquid crystal structure has a sharper selection wavelength on the long wavelength side than on the short wavelength side. Therefore, part or all of the wavelength region of light reflected by the reflective layer and part or all of the wavelength region of light diffracted by the diffraction layer can be easily overlapped. That is, it becomes possible to easily and surely produce an authenticity display body in which it is extremely difficult to create a counterfeit product.

  Furthermore, in the authentic display according to the present invention, the wavelength region of the specific light reflected by the reflective layer may be out of the wavelength region of the specific light diffracted by the diffraction layer. According to such an authentic display, the light reflected by the reflective layer and the light diffracted by the diffraction layer can be distinguished by color. Therefore, the presence or absence of light reflected by the reflective layer and the presence or absence of light diffracted by the diffraction layer can be easily confirmed. Therefore, authenticity can be identified more accurately.

  Further, in the authentic display according to the present invention, the wavelength region having a light quantity more than half of the maximum light quantity in the light quantity distribution with respect to the wavelength of the light reflected by the reflective layer is a wavelength region of the light diffracted by the diffraction layer. You may make it remove | deviate from the wavelength range which has a light quantity more than half of the maximum light quantity in the light quantity distribution with respect to a wavelength. According to such an authentic display, the light reflected by the reflective layer and the light diffracted by the diffraction layer can be clearly distinguished by color. Therefore, the presence / absence of light reflected by the reflective layer and the presence / absence of light diffracted by the diffraction layer can be easily and reliably confirmed. Therefore, authenticity can be identified more accurately.

Furthermore, the authenticity display medium according to the present invention, the wavelength will have a maximum amount of light at the light amount distribution with respect to wavelength of light reflected by said reflective layer (selective center wavelength), the wavelength of the light diffracted by the diffraction layer The wavelength may be shorter than the wavelength (selected center wavelength) that has the maximum light amount in the light amount distribution with respect to. In general, a cholesteric regular liquid crystal structure has a sharper selection wavelength on the long wavelength side than on the short wavelength side. Therefore, the wavelength region of the light reflected by the reflective layer and the wavelength region of the light diffracted by the diffraction layer can be more clearly distinguished. Therefore, according to such an authenticity display, authenticity can be determined more accurately.

Furthermore, in the authenticity display body according to the present invention, the reflection part of the reflection layer may be formed so as to overlap only a part of the diffraction layer. That is, the reflection part may be patterned on the diffraction layer. According to such an authentic display, the light reflected by the reflective layer can be visually recognized as a pattern corresponding to the area occupied by the reflective portion. Therefore, the presence or absence of light reflected by the reflective layer can be clearly recognized. Thereby, authenticity can be determined more accurately.

  Furthermore, in the authenticity display body according to the present invention, the cholesteric regular structure of the reflecting portion may be in a planar alignment state. According to such an authentic display, specific light is specularly reflected (specularly reflected) by the reflective layer, so that the reflected light can be visually recognized more clearly. Therefore, the presence or absence of light reflected by the reflective layer can be clearly recognized. Thereby, authenticity can be determined more accurately.

  Furthermore, in the authenticity display body according to the present invention, the reflective layer may further include a transmission part that transmits incident light. According to such an authentic display, the light reflected by the reflective layer can be visually recognized as a pattern corresponding to the area occupied by the reflective portion. Therefore, the presence or absence of light reflected by the reflective layer can be clearly recognized. Thereby, authenticity can be determined more accurately. In this case, the reflection layer may include a plurality of reflection portions and a plurality of transmission portions arranged side by side.

  Furthermore, in the authenticity display body according to the present invention, only a part of the reflection part may be in a planar alignment state. According to such an authentic display, the light reflected by the reflective layer can be visually recognized as a pattern corresponding to the shape occupied by the region where the liquid crystal structure is in the planar alignment state. Therefore, the presence or absence of light reflected by the reflective layer can be clearly recognized. Thereby, authenticity can be determined more accurately.

  Furthermore, the authenticity display body according to the present invention further includes an adhesive layer that is arranged on the back surface side opposite to the observation surface side than the reflective layer and the diffraction layer, and can be applied to an object. It may be. In this case, it can be easily attached to various objects.

  Furthermore, the authenticity display body according to the present invention may further include a peelable peeling member that is laminated on the back side of the adhesive layer. In this case, the authenticity indicator can be provided as a label. In addition, handling of the authenticity display body (for example, handling during distribution) is facilitated.

  Furthermore, in the authentic display according to the present invention, the diffraction layer may be formed of a reflection type volume hologram.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, the authenticity display body 101 is formed in a sheet shape so that the authenticity can be identified by observing reflected light. The authentic display body 101 includes a reflective layer 12a having a cholesteric regular liquid crystal structure and reflecting specific light (also referred to as a reflective region) 12a, and a volume hologram, and diffracts specific light. And a diffraction layer 15.

  Further, in the example shown in FIG. 1, the authentic display 101 includes a protective layer 11 and a reflective layer (hereinafter also referred to as a liquid crystal layer or a cholesteric liquid crystal layer) 12 arranged in order from the observation surface 5 side. A support base layer (adhesive PET layer) 13, a first adhesive layer 14, a diffraction layer 15, a second adhesive layer 16, a base layer (black PET layer) 17, and a third adhesive layer ( (Affixing layer) 18 and a fourth separator 19 are provided. In the present embodiment, the diffractive layer 15 is composed of a Lippmann hologram that is a reflective volume hologram. Therefore, the diffraction by the diffraction layer 15 in the present embodiment corresponds to reflection. In the description of the embodiments below, “reflection” by the diffraction layer 15 means “diffraction” unless otherwise specified.

  Among these, the reflection layer 12 and the diffraction layer (hereinafter also referred to as Lippmann hologram layer) 15 will be described. The other layers of the authenticity display body 101 shown in FIG. 1 will be described later.

  First, the reflective layer 12 will be described in detail.

  FIG. 2 is a diagram showing the reflective layer 12 and the diffraction layer 15 as viewed from the observation surface side. 2 (a) is a diagram showing only the reflective layer 12 viewed from the observation surface side, and FIG. 2 (b) is a diagram showing the reflective layer 12 visually observed through a circularly polarizing plate for a part. (c) is a figure which shows only the diffraction layer visually observed from the observation surface side, FIG.2 (d) is a figure which shows the laminated body of the reflective layer and diffraction layer visually observed from the observation surface side, FIG. e) is a diagram showing a laminate of a reflective layer and a diffractive layer, part of which is viewed through a circularly polarizing plate.

  The reflective layer 12 has a cholesteric regular liquid crystal structure (hereinafter also referred to as a cholesteric liquid crystal structure). Therefore, the reflection layer 12 reflects light in a specific wavelength region and reflects only circularly polarized light in one direction, and transmits light outside the wavelength region and circularly polarized light in the reverse direction. And the authenticity display body 101 in this Embodiment utilizes this effect | action of the reflective layer 12 as a 1st authenticity determination function.

  The reflective layer 12 can be formed generally as follows. First, a liquid crystalline composition that can have a cholesteric regular liquid crystal structure is applied to a support base layer 13 (in the specific example shown in FIG. 1, an easy-adhesion PET layer) 13 described later, a roll coating method, a gravure coating method, Apply using the bar coat method. Thereafter, an alignment treatment is performed on the liquid crystalline composition to align the cholesteric liquid crystal molecules and develop a cholesteric liquid crystal structure. Next, the cholesteric liquid crystal structure is fixed.

  Here, as shown in FIGS. 3A and 3B, in the cholesteric liquid crystal structure, the physical molecular arrangement of the liquid crystal molecules has a helical structure so that the director of the liquid crystal molecules rotates. The cholesteric liquid crystal structure (reflective layer 12) has a polarization separation characteristic that separates a circularly polarized component in one direction and a circularly polarized component in the opposite direction based on the physical molecular arrangement of the liquid crystal molecules. is doing. That is, unpolarized light incident on the reflective layer 12 is separated into two polarization states (right circularly polarized light and left circularly polarized light), one of which is reflected and the other is transmitted. Accordingly, the cholesteric liquid crystal structure of the reflective portion 12a of the reflective layer 12 is fabricated so as to reflect only the right circularly polarized light, and the reflective layer 12 is visually observed through the circularly polarizing plate 50 that transmits only the left circularly polarized light. In this case, as shown in FIG. 2B, the reflected light from the reflective layer 12 that has been visible until then cannot be visually recognized.

  In the following description, it is assumed that the reflective layer 12 in this embodiment selectively reflects the right circular deflection and transmits the left circular deflection.

The phenomenon of reflecting only one circular deflection as described above is known as circular dichroism, and when a spiral winding direction in the spiral structure of liquid crystal molecules is appropriately selected, a circle having the same optical rotation direction as this spiral winding direction is known. The polarization component is selectively reflected. In this case, the maximum optical rotation light scattering occurs at the wavelength λ ₀ of the following equation (1).
λ ₀ = nav · p (1)
Here, p is the helical pitch length in the helical structure of the liquid crystal molecules (the length per pitch of the molecular helix of the liquid crystal molecules), and nav is the average refractive index in a plane orthogonal to the helical axis.

Further, the wavelength bandwidth Δλ of the reflected light at this time is expressed by the following equation (2). Here, Δn is a birefringence value.
Δλ = Δn · p (2)
That is, the non-polarized light incident on the reflecting portion 12a of the reflecting layer 12 having a cholesteric liquid crystal structure has a wavelength centered on the selective reflection center wavelength λ ₀ according to the polarization separation characteristic (polarization selectivity) as described above. One circularly polarized component (for example, right circular polarization) belonging to the range of the bandwidth Δλ (selective reflection wavelength region) is reflected, and the other light (for example, the left circular polarization component and right circular polarization outside the selective reflection wavelength region) Component) is transmitted.

  Therefore, by adjusting the wavelength region (selected wavelength region) of the light reflected by the reflecting portion 12a of the reflecting layer 12, the reflected light from the reflecting portion 12a of the reflecting layer 12 can be visually recognized as a desired color. can do. For example, the wavelength region corresponding to the half-value width of the light reflected by the reflecting portion 12a of the reflecting layer 12, in other words, more than half of the maximum reflected light amount in the light amount distribution with respect to the wavelength of the light reflected by the reflecting portion 12a of the reflecting layer 12. If the wavelength region in which the amount of light can be secured is 480 to 540 nm, the reflected light from the reflecting portion 12a is visually recognized as green. As another example, if the wavelength region in which the light quantity more than half of the maximum reflected light quantity is secured in the light quantity distribution with respect to the wavelength of the light reflected by the reflective part 12a is 605 to 675 nm, the reflected light from the reflective part 12a is red. As visible.

  The reflective portion 12 a of the reflective layer 12 may be uniformly formed on the entire observation surface side of the support base material layer (easily adhesive PET layer) 13. In this case, the green or red light reflected by the above-described reflecting portion 12a is observed in a planar shape.

  On the other hand, as shown to Fig.2 (a), the reflection part 12a of the reflection layer 12 may be formed only in a part on surface by the side of the observation surface of the support base material layer (easily-adhesive PET layer) 13. FIG. Such a reflective layer 12 can be produced by partially curing a liquid crystal composition disposed on a support substrate under different conditions, as disclosed in Japanese Patent Application Laid-Open No. 2004-133179. The reflective layer 12 formed by such a method includes a reflective portion 12a and a transmissive portion (also referred to as a transmissive region) 12b that transmits incident light (see FIG. 2).

  Further, the liquid crystal composition that forms the reflective portion 12a is disposed only on a part of the support base material layer using, for example, a gravure printing machine, so that the reflective part 12a is only on a part of the support base material layer 13. The formed reflective layer 12 can also be produced. In the reflective layer 12 obtained by such a method, the reflective portion 12a can overlap only a part of the diffraction layer 15.

  In the example shown in FIG. 2, the reflective layer 12 includes a plurality of reflecting portions 12a (shaded portions) and a plurality of transmitting portions 12b arranged side by side. The plurality of reflecting portions 12a form a lattice pattern. In this case, the green and red light reflected by the reflection part 12a mentioned above is observed as this pattern. That is, the light reflected by the reflective layer 12 can be visually recognized as a pattern corresponding to the area occupied by the reflective portion 12a. Therefore, the presence or absence of light reflected by the reflective layer 12 can be clearly recognized.

  In addition, when forming the reflection part 12a only in a part on the support base material layer 13, the reflectance as the reflection layer 12 whole can be adjusted by adjusting the area of the reflection part 12a.

  The pattern of the reflective layer 12 may be large enough to be visually confirmed as a lattice pattern, or may be small enough not to be visually confirmed as a lattice pattern.

  As shown in FIGS. 3A and 3B, the cholesteric liquid crystal structure includes a plurality of spiral structure regions. In the example shown in FIG. 3A, the reflection portion 12a of the reflection layer 12 having a cholesteric liquid crystal structure includes a plurality of spiral structure regions having different spiral axis directions. According to such a reflection part 12a, the selectively reflected light can be diffused by the structural nonuniformity of the cholesteric liquid crystal structure.

  On the other hand, in the example shown in FIG. 3B, the cholesteric regular structure is in a so-called planar alignment state. That is, the directions of the helical axes of the respective helical structure regions included in the cholesteric liquid crystal structure all extend uniformly in parallel with the layer thickness direction. According to such a reflection part 12a, the selectively reflected light is specularly reflected (regular reflection), and the reflected light can be clearly recognized. Moreover, it comes to have the angle dependence from which a color changes with viewing angles. As a result, the presence or absence of light reflected from the reflective layer 12 can be clearly recognized.

  It should be noted that alignment processing is required as will be described in detail later, regardless of the cholesteric liquid crystal structure shown in FIGS. 3A and 3B. Then, by performing the alignment treatment under partially different conditions, only a part of the reflective portion 12a of the reflective layer 12 can be brought into the planar alignment state. In this case, among the light reflected by the reflecting portion 12a of the reflective layer 12, the light reflected by the portion in the planar alignment state can be viewed more brightly. That is, the presence or absence of light reflected by the reflective layer 12 can be determined by whether or not a pattern corresponding to the shape occupied by the region where the cholesteric liquid crystal structure is in the planar alignment state is visually recognized. Therefore, the presence or absence of light reflected by the reflective layer 12 can be clearly recognized.

  Next, a method for producing the reflective layer 12 will be described in detail.

  As the liquid crystalline composition applied on the support base layer 13, chiral nematic liquid crystal or cholesteric liquid crystal exhibiting cholesteric regularity can be used. Such a material is not particularly limited as long as it is a liquid crystal material capable of forming a cholesteric liquid crystal structure including a helical structure region (see FIGS. 3A and 3B). A polymerizable liquid crystal material having the functional group is preferable for obtaining an optically stable reflective layer 12 after curing.

Hereinafter, the case where a chiral nematic liquid crystal is used as the liquid crystalline composition will be described as an example. The chiral nematic liquid crystal is a mixture of a polymerizable liquid crystal material exhibiting nematic regularity and a chiral agent. Here, the chiral agent is for controlling the helical pitch length of the polymerizable liquid crystal material exhibiting nematic regularity, and for allowing the liquid crystalline composition to exhibit cholesteric regularity as a whole. Then, by adjusting the mixing ratio of the nematic liquid crystal and the chiral agent, the helical pitch length in the above-described formulas (1) and (2) can be controlled, whereby the selective reflection wavelength center λ ₀ and the wavelength can be controlled. The bandwidth Δλ can be adjusted. In addition, a photopolymerization initiator and an appropriate additive are added to such a liquid crystalline composition.

Examples of polymerizable liquid crystal materials exhibiting nematic regularity include, for example, compounds represented by the following general formula (1) and compounds represented by the following formulas (2-i) to (2-xi). Can be mentioned. These compounds can be used alone or in combination.

  In the general formula (1), R1 and R2 each represent hydrogen or a methyl group, but it is preferable that both R1 and R2 are hydrogen because of the wide temperature range showing the liquid crystal phase. X may be hydrogen, chlorine, bromine, iodine, an alkyl group having 1 to 4 carbon atoms, a methoxy group, a cyano group, or a nitro group, but is preferably a chlorine or methyl group. Moreover, in the said General formula (1), a and b which show the chain length of the alkylene group which is a spacer of the (meth) acryloyloxy group and aromatic ring of both ends of a molecular chain are arbitrary in the range of 2-12, respectively. Although it can take an integer, it is preferably in the range of 4 to 10, and more preferably in the range of 6 to 9. The compound of the general formula (1) in which a = b = 0 is poor in stability, easily subjected to hydrolysis, and the compound itself has high crystallinity. In addition, the compound of the general formula (1) in which a and b are each 13 or more has a low isotropic transition temperature (TI). For this reason, both of these compounds are not preferable because the temperature range in which the liquid crystal phase is exhibited is narrow.

  In the above, examples of polymerizable liquid crystal monomers have been described as polymerizable liquid crystal materials exhibiting nematic regularity, but not limited thereto, polymerizable liquid crystal oligomers, polymerizable liquid crystal polymers, liquid crystal polymers, etc. It is also possible to use it. Such a polymerizable liquid crystal oligomer, polymerizable liquid crystal polymer and liquid crystal polymer can be appropriately selected from those conventionally proposed.

  On the other hand, a chiral agent is a low molecular compound having an optically active site, and is mainly a compound having a molecular weight of 1500 or less. The chiral agent is mainly used for the purpose of inducing a helical structure in the positive uniaxial nematic regularity expressed by the polymerizable liquid crystal material exhibiting nematic regularity. As long as this purpose is achieved, it is compatible with a polymerizable liquid crystal material exhibiting nematic regularity in a solution state or a molten state, without impairing the liquid crystal property of the polymerizable liquid crystal material exhibiting nematic regularity, The kind of the low molecular compound as the chiral agent is not particularly limited as long as it can induce a desired helical structure.

  In addition, the chiral agent used for inducing a helical structure in the liquid crystal in this way needs to have at least some chirality in the molecule. Accordingly, the chiral agent used here includes, for example, a compound having one or more asymmetric carbons, a compound having an asymmetric point on a heteroatom such as a chiral amine or chiral sulfoxide, or a cumulene. And compounds having an optically active moiety having axial asymmetry such as binaphthol. More specifically, a commercially available chiral nematic liquid crystal (for example, chiral dopant liquid crystal S-811 (manufactured by Merck)) can be mentioned.

However, depending on the properties of the selected chiral agent, the nematic regularity formed by the polymerizable liquid crystal material exhibiting nematic regularity, the orientation deterioration, or the liquid crystallinity when the chiral agent is non-polymerizable. There exists a possibility of causing the fall of the sclerosis | hardenability of a composition, and the fall of the reliability of the film after hardening. Furthermore, the use of a large amount of a chiral agent having an optically active site causes an increase in the cost of the liquid crystal composition. Therefore, when a polarization selective reflection layer having a cholesteric regularity with a short helical pitch length is formed, a chiral agent having an optically active site to be contained in the liquid crystalline composition has a large effect of inducing a helical structure. It is preferable to select an agent. Specifically, it is preferable to use a low molecular compound having axial asymmetry in the molecule as represented by the following general formula (3), (4) or (5). .

  In the general formula (3) or (4), R4 represents hydrogen or a methyl group. Y is any one of formulas (i) to (xxiv) shown above, and among them, any one of formulas (i), (ii), (iii), (v), and (vii) Preferably there is. Moreover, although c and d which show the chain length of an alkylene group can each take arbitrary integers in the range of 2-12, it is preferable that it is the range of 4-10, and is the range of 6-9. Is more preferable. The compound of the above general formula (3) or (4) in which the value of c or d is 0 or 1 lacks stability, is susceptible to hydrolysis, and has high crystallinity. On the other hand, a compound having a value of c or d of 13 or more has a low melting point (Tm). In these compounds, compatibility with a polymerizable liquid crystal material exhibiting nematic regularity is lowered, and phase separation or the like may occur depending on the concentration.

  In addition, such a chiral agent does not need to have polymerizability in particular. However, when the chiral agent has polymerizability, it is polymerized with a polymerizable liquid crystal material exhibiting nematic regularity, and the cholesteric regularity is stably fixed, so in terms of thermal stability, etc. Highly preferred. In particular, it is preferable to have a polymerizable functional group at both ends of the molecule in order to obtain the reflective layer 12 with good heat resistance.

  The amount of the chiral agent contained in the liquid crystal composition is determined in consideration of the ability to induce a helical structure, the finally obtained cholesteric liquid crystal structure, and the like. Specifically, although it varies greatly depending on the material of the liquid crystal composition used, 0.01 to 60 parts by weight, preferably 0.1 to 40 parts by weight, per 100 parts by weight of the total amount of the liquid crystal composition. More preferably, it is selected in the range of 0.5 to 30 parts by weight, most preferably 1 to 20 parts by weight. When the content of the chiral agent is less than the above range, sufficient cholesteric regularity may not be imparted to the liquid crystal composition. When the content exceeds the above range, the alignment of the liquid crystal molecules is inhibited. There is a risk of adverse effects when cured by actinic radiation.

  Further, the liquid crystalline composition can be applied as it is on the support substrate layer 13, but it is dissolved in an appropriate solvent such as an organic solvent for the purpose of adjusting the viscosity to a coating apparatus or obtaining a good alignment state. It may be converted into ink.

  Such a solvent is not particularly limited as long as it can dissolve the polymerizable liquid crystal material as described above, but is preferably one that does not erode the support base material layer 13. Specific examples include acetone, 3-methoxybutyl acetate, diglyme, cyclohexanone, tetrahydrofuran, toluene, xylene, chlorobenzene, methylene chloride, methyl ethyl ketone, and the like. The degree of dilution of the polymerizable liquid crystal material is not particularly limited, but it is 5 to 50%, more preferably 10 in view of the fact that the liquid crystal itself is a material with low solubility and high viscosity. It is preferable to dilute to about 30%.

(Orientation process)
In the coating step described above, after the liquid crystalline composition is coated on the support base layer 13 to form the cholesteric liquid crystal layer 12, the cholesteric liquid crystal layer (reflective layer) 12 develops a cholesteric liquid crystal structure in the alignment treatment step. While maintaining a predetermined temperature, the liquid crystal molecules in the cholesteric liquid crystal layer 12 are aligned.

  3A and 3B are diagrams for explaining a cholesteric liquid crystal structure.

  3A and 3B, the light incident on the reflective layer 12 is a light beam 31R, and the reflected light is a light beam 33 in FIG. 3A and a light beam 36 in FIG. 3B. In FIG. 3A, the directions of the reflected light vary, and in FIG. 3B, the principal ray directions of the reflected light are aligned.

  As described above, the cholesteric liquid crystal structure may be in an orientation state in which the directions of the spiral axes L of the plurality of spiral structure regions 30 vary within the layer, as shown in FIG. 3A, or as shown in FIG. 3B. Planar alignment state may be used. However, in either case, alignment treatment is necessary. That is, in the former, an alignment process that forms a plurality of helical structure regions 30 in the cholesteric liquid crystal structure is necessary, and in the latter, an alignment process that forms a plurality of helical structure regions 30 in the cholesteric liquid crystal structure. In addition, an alignment process is required to align the directors of liquid crystal molecules having a cholesteric liquid crystal structure in a certain direction on the support base layer 13.

  Here, when the cholesteric liquid crystal layer (reflective layer) 12 formed on the support base layer 13 is maintained at a predetermined temperature at which the cholesteric liquid crystal structure is developed, the cholesteric liquid crystal layer 12 exhibits a liquid crystal phase, and the liquid crystal molecules themselves A self-assembling action forms a helical structure formed by rotating directors of liquid crystal molecules. If the cholesteric liquid crystal layer 12 is not diffused, the directors of liquid crystal molecules having a cholesteric liquid crystal structure are aligned on the support base layer 13 in a certain direction. And the cholesteric liquid crystal structure expressed in such a liquid crystal phase state can be fixed by curing the cholesteric liquid crystal layer 12 by a method as described later.

  Such an alignment treatment step is usually performed together with a drying treatment for removing the solvent when the solvent is contained in the liquid crystalline composition applied on the support base material layer 13. In order to remove the solvent, a drying temperature of 40 to 120 ° C., preferably 60 to 100 ° C. is suitable, and the drying time (heating time) should be such that the cholesteric liquid crystal structure appears and the solvent is substantially removed. For example, 15 to 600 seconds are preferable, and 30 to 180 seconds are more preferable.

  When it is found that the orientation state is insufficient after drying, the heating time may be appropriately extended. In addition, when using the vacuum drying method in such a drying process, it is preferable to perform a separate heat treatment for the alignment process.

(Curing process)
After aligning the liquid crystal molecules in the cholesteric liquid crystal layer (reflection layer) 12 in the alignment process described above, the cholesteric liquid crystal layer 12 is cured in the curing process to fix the cholesteric liquid crystal structure expressed in the liquid crystal phase. Turn into.

  As a method used in the curing treatment step, (1) a method of drying a solvent in the liquid crystalline composition, (2) a method of polymerizing liquid crystal molecules in the liquid crystalline composition by heating, and (3) by irradiation with radiation. A method of polymerizing liquid crystal molecules in the liquid crystal composition, and (4) a method combining these methods can be used.

  Among these methods, the method (1) is a method suitable when a liquid crystal polymer is used as a polymerizable liquid crystal material exhibiting nematic regularity contained in the liquid crystal composition that is a material of the cholesteric liquid crystal layer 12. . In this method, the liquid crystal polymer is applied to the support base material layer 13 in a state in which it is dissolved in a solvent such as an organic solvent. In this case, the cholesteric regularity can be obtained only by removing the solvent by a drying treatment. The solidified cholesteric liquid crystal layer 12 is formed. In addition, about the kind of solvent, drying conditions, etc., what was described in the apply | coating process and orientation process mentioned above can be used.

  The method (2) is a method of curing the cholesteric liquid crystal layer 12 by thermally polymerizing liquid crystal molecules in the liquid crystalline composition by heating. In this method, since the bonding state of the liquid crystal molecules changes depending on the heating (baking) temperature, if there is temperature unevenness in the plane of the cholesteric liquid crystal layer 12 during heating, physical properties such as film hardness and optical characteristics are uneven. . Here, in order to keep the film hardness distribution within ± 10%, the heating temperature distribution is also preferably within ± 5%, and more preferably within ± 2%.

  The method for heating the cholesteric liquid crystal layer 12 formed on the support base layer 13 is not particularly limited as long as the uniformity of the heating temperature can be obtained. A method can be used in which a slight air layer is provided between and held in parallel with the hot plate. Moreover, the method of leaving still in the apparatus which heats the whole specific space like an oven, or letting the inside of the said apparatus pass is also sufficient. In the case of using a film coater or the like, it is preferable to lengthen the drying zone so that a sufficient heating time can be taken.

  In general, a heating temperature of 100 ° C. or higher is required as the heating temperature, but it is preferably about 150 ° C. due to the heat resistance of the support base material layer 13. However, if a film or the like specialized for heat resistance is used as the material of the support base material layer 13, heating at a high temperature of 150 ° C. or higher is also possible.

  The method (3) is a method of curing the cholesteric liquid crystal layer 12 by photopolymerizing liquid crystal molecules in the liquid crystalline composition by irradiation with radiation. In this method, an electron beam, ultraviolet rays, or the like can be appropriately used as radiation according to conditions. Usually, ultraviolet rays are preferably used from the viewpoint of easiness of the apparatus, and the wavelength is 250 to 400 nm. Here, when ultraviolet rays are used, it is preferable that a photopolymerization initiator is added to the liquid crystalline composition.

  Examples of the photopolymerization initiator added to the liquid crystal composition include benzyl (also referred to as bibenzoyl), benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoyl benzoic acid, benzoyl methyl benzoate, 4-benzoyl-4'- Methyl diphenyl sulfide, benzyl methyl ketal, dimethylaminomethyl benzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3'-dimethyl-4-methoxybenzophenone, methylobenzoylpho Mate, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- ON, 1- ( -Dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) 2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxy Examples include thioxanthone. In addition to the photopolymerization initiator, it is also possible to add a sensitizer as long as the necessary functions of the cholesteric liquid crystal layer 12 are not impaired.

  The addition amount of the photopolymerization initiator added to the liquid crystal composition is 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. Is preferred. By performing the above-described series of steps (coating step, alignment step and curing step), the reflective layer 12 (strictly, the reflective portion 12a of the reflective layer 12) is laminated on the support base layer 13 ( Can be fixed).

  Next, the diffraction layer 15 will be described in detail.

  In the present embodiment, the diffraction layer 15 is a reflective volume hologram layer, and interference fringes are recorded in the layer. Therefore, the diffraction layer 15 is light in a specific wavelength region, and reflects (diffracts) light incident on the diffraction layer 15 at a predetermined incident angle. And the authenticity display body 101 in this Embodiment utilizes this effect | action of the diffraction layer 15 as a 2nd authenticity determination function.

  In the present embodiment, as shown in FIGS. 2C, 2D, and 2E, an image is recorded on the volume hologram that forms the diffraction layer 15. Therefore, an image can be visually recognized as reflected light (diffracted light) from the diffraction layer 15. This diffractive layer 15 is capable of switching images by moving the viewpoint in two directions, the vertical direction and the horizontal direction. As a result, it is possible to reproduce a three-dimensional image or a deep image.

  Next, a method for producing the diffraction layer 15 will be described in detail. First, materials used for forming the volume hologram layer will be described.

  A conventionally known volume hologram recording material can be used as the hologram material. Specific examples include silver salt sensitive materials, dichromated gelatin, photocrosslinked polymers, and photopolymers. In particular, a photopolymer can produce a volume hologram only by a dry process as compared with other materials, and is an excellent material for mass production. In the present embodiment, the photopolymer used as the hologram material has at least one photopolymerizable compound and a photopolymerization initiator. Hereinafter, each constituent material of the photopolymer for volume hologram recording will be described.

(1. Photopolymerizable compound)
In the present embodiment, photopolymerizable compounds that can be used will be described. The photopolymerizable compound in the present embodiment may be a radical photopolymerizable compound or a cationic photopolymerizable compound. Hereinafter, the description will be divided into a photoradical polymerizable compound and a photocationic polymerizable compound.

(A. Photoradical polymerizable compound)
In the present embodiment, as a radical photopolymerizable compound that can be used, when a volume hologram is formed using the volume hologram resin composition of the present invention, for example, photo radical polymerization described later by laser irradiation or the like. The compound is not particularly limited as long as it is a compound that is polymerized by the action of active radicals generated from the initiator, but a compound having at least one addition-polymerizable ethylenically unsaturated double bond can be used. For example, an unsaturated carboxylic acid, an unsaturated carboxylate, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, an amide bond between an unsaturated carboxylic acid and an aliphatic polyhydric amine compound, and the like can be given. . Specific examples of the monomer of the ester of the unsaturated carboxylic acid and the aliphatic polyhydric alcohol compound are shown below.

  Acrylic esters include ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylol Methylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate Dipentaerythritol diacrylate, Pentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, 2-phenoxyethyl Acrylate, phenol ethoxylate monoacrylate, 2- (p-chlorophenoxy) ethyl acrylate, p-chlorophenyl acrylate, phenyl acrylate, 2-phenylethyl acrylate, (2-acryloxyethyl) ether of bisphenol A, ethoxylated bisphenol A diacrylate, 2- (1-naphthy Oxy) ethyl acrylate, o-biphenyl acrylate, 9,9-bis (4-acryloxydiethoxyphenyl) fluorene, 9,9-bis (4-acryloxytriethoxyphenyl) fluorene, 9,9-bis (4- Acryloxydipropoxyphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3-methylphenyl) fluorene, 9,9-bis (4-acryloxyethoxy-3-ethylphenyl) fluorene, 9,9- Examples thereof include bis (4-acryloxyethoxy-3,5-dimethyl) fluorene.

  A sulfur-containing acrylic compound can also be used. For example, 4,4′-bis (β-acryloyloxyethylthio) diphenyl sulfone, 4,4′-bis (β-acryloyloxyethylthio) diphenyl ketone, 4,4′-bis (β-acryloyloxyethylthio) 3,3 ′, 5,5′-tetrabromodiphenyl ketone, 2,4-bis (β-acryloyloxyethylthio) diphenyl ketone and the like can be mentioned.

  Further, as the methacrylic acid ester, among the compound names exemplified in the above-mentioned acrylic acid ester, “acrylate” is converted to “methacrylate”, “acryloxy” is converted to “methacryloxy”, and “acryloyl” is converted to “methacryloyl”. The exemplified compounds are exemplified.

  Furthermore, the said photoradically polymerizable compound may be used 1 type or in combination of 2 or more types.

(B. Photocationic polymerizable compound)
The photocationically polymerizable compound used in the present embodiment is a compound that undergoes cation polymerization by Bronsted acid or Lewis acid generated by decomposition of a photocationic polymerization initiator described later upon energy irradiation. For example, cyclic ethers such as epoxy ring and oxetane ring, thioethers, vinyl ethers and the like can be mentioned.

  Examples of the compound containing the epoxy ring include polyalkylene glycol diglycidyl ether, bisphenol A diglycidyl ether, glycerin triglycidyl ether, diglycerol triglycidyl ether, diglycidyl hexahydrophthalate, trimethylolpropane diglycidyl ether, allyl glycidyl ether. , Phenyl glycidyl ether, cyclohexene oxide and the like.

  Moreover, the said photocationic polymerizable compound may be used 1 type or in combination of 2 or more types.

  Furthermore, the photo radical polymerizable compound and the photo cation polymerizable compound may be used alone or in combination of two or more.

  Here, the formation of the volume hologram using the above-described resin composition for volume hologram can be performed as follows. First, the radically polymerizable compound is polymerized by, for example, irradiating the volume hologram resin composition with a laser in a desired image shape. Thereafter, the entire surface of the volume hologram resin composition is irradiated with energy to polymerize an uncured substance such as a photocationically polymerizable compound to form a volume hologram. Note that lasers or the like used for forming an image and energy irradiated with energy on the entire surface usually have different wavelengths. The photocationically polymerizable compound that can be used in the present embodiment is preferably a compound that forms an image, for example, that is not polymerized by a laser or the like.

  In addition, such a photo-cationic polymerizable compound is preferably in a liquid state at normal temperature because the polymerization of the photoradical polymerizable compound is preferably performed in a composition having a relatively low viscosity.

(C. Other)
The photopolymerizable compound that can be used in the present embodiment is used in a proportion of 10 to 1000 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the binder resin described later. Here, the volume hologram forms an interference fringe by polymerizing a photopolymerizable compound with, for example, laser light or light having excellent coherence, and forms an image. Therefore, in the case where the volume hologram resin composition contains a radical photopolymerizable compound and a cationic photopolymerizable compound, those having different refractive indexes are selected and used. The rate may be large. In the present embodiment, the average refractive index of the photoradically polymerizable compound is preferably larger than that of the photocationically polymerizable compound from the viewpoint of material selectivity. Specifically, the average refractive index is 0. 0.02 or more is preferable.

  This is because when the difference in the average refractive index between the photo radical polymerizable compound and the photo cationic polymerizable compound is lower than the above value, the refractive index modulation becomes insufficient, and it is difficult to form a high-definition image. Because there is a possibility of becoming. The average refractive index here means the average value of the refractive index measured for the polymer after polymerizing the photocationically polymerizable compound or the photoradical polymerizable compound. Here, the refractive index is a value measured by an Abbe refractometer.

(2. Photopolymerization initiator)
Next, a photopolymerization initiator that can be used in the present embodiment will be described. As a photoinitiator in this Embodiment, a kind changes with the photopolymerizable compounds mentioned above. That is, when the photopolymerizable compound is a photoradical polymerizable compound, the photopolymerization initiator selects a photoradical polymerization initiator, and when the photopolymerizable compound is a photocationic polymerizable compound, the photopolymerization initiator. It is necessary to select a photocationic polymerization initiator. Hereinafter, the radical photopolymerization initiator and the photocationic polymerization initiator will be described separately.

(A. Photoradical polymerization initiator)
As a radical photopolymerization initiator that can be used in the present embodiment, an active radical is generated by, for example, a laser irradiated when a volume hologram layer is formed using a resin composition for volume hologram, The initiator is not particularly limited as long as it is an initiator capable of polymerizing the radically polymerizable compound. For example, imidazole derivatives, bisimidazole derivatives, N-aryl glycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, and the like can be used. Specifically, 1,3-di (t-butyldioxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone, 3-phenyl-5-isoxazolone, 2-mercaptobenzimidazole, bis (2,4,5-triphenyl) imidazole, 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name Irgacure 651, manufactured by Ciba Specialty Chemicals) ), 1-hydroxy-cyclohexyl-phenyl-ketone (trade name Irgacure 184, manufactured by Ciba Specialty Chemicals), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (Product name: Irgacure 369, manufactured by Ciba Specialty Chemicals), screw (η 5-2,4-Cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium (trade name Irgacure 784, Ciba Specialty Chemicals Co., Ltd. )) And the like.

(B. Photocationic polymerization initiator)
The photocationic polymerization initiator that can be used in the present embodiment is not particularly limited as long as it generates Bronsted acid or Lewis acid by energy irradiation and polymerizes the photocationic polymerizable compound. . When the volume hologram resin composition contains a radical photopolymerizable compound and a cationic photopolymerizable compound, the cationic photopolymerizable compound is a polymer that specifically polymerizes the radical photopolymerizable compound, for example, light having excellent laser or coherence. It is preferable that the light is exposed to the energy irradiated to the entire surface after the reaction. Thereby, when the photo radical polymerizable compound is polymerized, the photo cation polymerizable compound can be allowed to exist with little reaction, and a large refractive index modulation in the volume hologram can be obtained.

  Specifically, sulfonic acid ester, imide sulfonate, dialkyl-4-hydroxysulfonium salt, arylsulfonic acid-p-nitrobenzyl ester, silanol-aluminum complex, (η6-benzene) (η5-cyclopentadienyl) iron ( II) etc. are exemplified. Furthermore, benzoin tosylate, 2,5-dinitrobenzyl tosylate, N-tosiphthalimide and the like can also be used.

(C. Other)
In the present embodiment, as a radical photopolymerization initiator and a photocationic polymerization initiator, aromatic iodonium salts, aromatic sulfonium salts, aromatic diazonium salts, aromatic phosphonium salts, triazine compounds, Examples thereof include iron arene complexes. Specifically, chlorides of iodonium such as diphenyliodonium, ditolyliodonium, bis (pt-butylphenyl) iodonium, bis (p-chlorophenyl) iodonium, bromide, borofluoride, hexafluorophosphate, hexafluoroantimony Iodonium salts such as nate salts, chlorides of sulfonium such as triphenylsulfonium, 4-t-butyltriphenylsulfonium, tris (4-methylphenyl) sulfonium, bromides, borofluoride salts, hexafluorophosphate salts, hexafluoroantimonate salts Sulfonium salts such as 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2-methyl -4,6- Scan (trichloromethyl) -1,3,5-2,4,6-substituted-1,3,5-triazine compounds such as triazine. Moreover, said photoinitiator may be used 1 type or in combination of 2 or more types. Further, the photopolymerization initiator is used in a proportion of 0.1 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the binder resin described later.

(3. Additives)
Next, the additive that can be added to the volume hologram resin composition in the present embodiment will be described.

(A. Sensitizing dye)
In the present embodiment, it is preferable that the volume hologram tree composition contains a sensitizing dye. Many of the above photopolymerizable compounds and photopolymerization initiators are active with respect to ultraviolet rays, but addition of a sensitizing dye makes them also active with visible light and can record interference fringes using visible laser light. This is because it becomes possible. Such a sensitizing dye is selected in consideration of the wavelength of the laser beam used when recording interference fringes, but is not particularly limited. For example, thiopyrylium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, coumarin dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes, pyrylium System dyes, cyclopentanone dyes, cyclohexanone dyes, and the like can be used.

  Examples of the cyanine dye and merocyanine dye include 3,3′-dicarboxyethyl-2,2′-thiocyanine bromide, 1-carboxymethyl-1′-carboxyethyl-2,2′-quinocyanine bromide, 1 , 3′-diethyl-2,2′-quinothiocyanine iodide, 3-ethyl-5-[(3-ethyl-2 (3H) -benzothiazolidelidene) ethylidene] -2-thioxo-4-oxazolidine, etc. Is mentioned. Examples of the coumarin dyes and ketocoumarin dyes include 3- (2′-benzimidazole) 7-N, N-diethylaminocoumarin, 3,3′-carbonylbis (7-diethylaminocoumarin), and 3,3′-. Examples include carbonylbiscoumarin, 3,3′-carbonylbis (5,7-dimethoxycoumarin), 3,3′-carbonylbis (7-acetoxycoumarin), and the like.

  When the diffraction layer 15 made of a volume hologram layer is provided closer to the observation surface than the reflection layer 12, the diffraction layer 15 made of a volume hologram layer is required to have high transparency. Therefore, in such a case, it is preferable that the sensitizing dye having an absorption wavelength in the visible light region becomes colorless by being decomposed by a post-process after recording interference fringes, heating or ultraviolet irradiation. As such a sensitizing dye, the above-mentioned cyanine dye is preferably used. The sensitizing dye is used in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the binder resin described below.

(B. Binder resin)
In the present embodiment, it is preferable that the volume hologram resin composition contains a binder resin. By containing the binder resin, the film formability and the film thickness uniformity can be improved, and the recorded interference fringes can be stably present.

  Examples of such a binder resin include polymethacrylic acid ester or a partially hydrolyzed product thereof, polyvinyl acetate or a hydrolyzed product thereof, polyvinyl alcohol or a partially acetalized product thereof, triacetyl cellulose, polyisoprene, polybutadiene, polychloroprene, and silicone. Rubber, polystyrene, polyvinyl butyral, polyvinyl chloride, polyarylate, chlorinated polyethylene, chlorinated polypropylene, poly-N-vinyl carbazole or derivatives thereof, poly-N-vinyl pyrrolidone or derivatives thereof, co-use of styrene and maleic anhydride Examples thereof include polymers or half esters thereof. And at least one monomer selected from the group consisting of copolymerizable monomers such as acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, acrylamide, acrylonitrile, ethylene, propylene, vinyl chloride, and vinyl acetate A copolymer obtained by polymerizing can also be used. Moreover, the copolymer formed by polymerizing the monomer which has a functional group which can be thermoset or photocured in a side chain can also be used. Furthermore, 1 type, or 2 or more types of mixtures can also be used.

As the binder resin, an oligomer type curable resin may be used. For example, the epoxy compound etc. which are produced | generated by the condensation reaction of various phenol compounds, such as bisphenol A, bisphenol S, novolak, o-cresol novolak, p-alkylphenol novolak, and epichlorohydrin, are mentioned. Furthermore, as the binder resin, an organic-inorganic hybrid polymer using a sol-gel reaction can also be used. For example, the copolymer of the organometallic compound which has a polymeric group represented by following General formula (6), and a vinyl monomer is mentioned.
Rm M (OR ′) n (6)
Here, M is a metal such as Si, Ti, Zr, Zn, In, Sn, Al, Se, R is a vinyl group or (meth) acryloyl group having 1 to 10 carbon atoms, and R ′ is a carbon number having 1 to 10 carbon atoms. Represents an alkyl group, and m + n is the valence of the metal M.

  Examples of organometallic compounds when Si is used as the metal M include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltributoxysilane, vinyltriallyloxysilane, vinyltetraethoxysilane, vinyltetramethoxysilane, acryloxy Examples thereof include propyltrimethoxysilane and methacryloxypropyltrimethoxysilane.

  Examples of the vinyl monomer include acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester.

Here, the volume hologram is formed by recording interference fringes as refractive index modulation or transmittance modulation. Therefore, it is preferable that the refractive index difference between the binder resin and the photopolymerizable compound is large. In the present embodiment, in order to increase the difference in refractive index between the binder resin and the photopolymerizable compound, an organometallic compound represented by the following general formula (7) is added to the volume hologram resin composition. You can also
M (OR ") k (7)
Here, M represents a metal such as Ti, Zr, Zn, In, Sn, Al, and Se, R ″ represents an alkyl group having 1 to 10 carbon atoms, and k represents the valence of the metal M.

  When the compound represented by the general formula (7) is added to the volume hologram resin composition, a network structure is formed with the binder resin by a sol-gel reaction in the presence of water and an acid catalyst. Accordingly, not only the refractive index of the binder resin is increased, but also the effect of improving the toughness and heat resistance of the film is obtained. Therefore, in order to increase the refractive index difference from the photopolymerizable compound, it is preferable to use a metal M having a high refractive index. The binder resin is usually used in the volume hologram composition in the range of 15 to 50% by weight, preferably in the range of 20 to 40% by weight.

  Next, formation of the volume hologram layer will be described.

  For the formation of the volume hologram layer, first, the resin composition for volume hologram is applied on, for example, a target substrate film by a general coating means, and dried as necessary to form a volume hologram. Layer. Further, the volume hologram forming layer may be formed, for example, by injecting a volume hologram resin composition between two substrates such as a glass plate. Next, the above-described photopolymerizable compound is polymerized on the above-mentioned volume hologram forming layer by exposure with laser light (light with excellent coherence (for example, light having a wavelength of 300 nm to 1200 nm)) that is usually used in a holographic exposure apparatus. The interference fringes of the target image are recorded. Thereby, a volume hologram layer is formed.

  The volume hologram resin composition may be used with a solvent, if necessary, at the time of coating. Examples of such solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, benzene, toluene, xylene, chlorobenzene, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, ethyl acetate, 1,4- Dioxane, 1,2-dichloroethane, dichloromethane, chloroform, methanol, ethanol, isopropanol and the like can be used. These solvents may be used alone or in combination of two or more. Moreover, as a coating method of the volume hologram resin composition, methods such as a spin coater, a gravure coater, a comma coater, and a bar coater can be used.

The coating amount of the volume hologram resin composition for volume type but those selected appropriately depending on the application and type of hologram layer, usually in the range of ^{1g / m 2 ~100g / m 2} , preferably 2 g / m ² is in the range of to 40 g / m ^2, the thickness of the volume hologram-forming layer is generally 1 m to 100 m, is preferably in the range of inter alia 2Myuemu～40myuemu. Furthermore, the film thickness of the volume hologram layer formed by curing the volume hologram resin composition is preferably in the range of 1 to 100 μm, more preferably 10 to 40 μm.

  The above-described volume hologram forming layer is polymerized by the above-described photopolymerizable compound by exposure with laser light (light with excellent coherence (for example, light with a wavelength of 300 nm to 1200 nm)) that is usually used in a holographic exposure apparatus, Record the interference fringes of the desired image. As the laser beam, a visible laser, for example, an argon ion laser (458 nm, 488 nm, 514.5 nm), a krypton ion laser (647.1 nm), a helium-neon laser (633 nm), a YAG laser (532 nm), or the like is used. Can do.

  As a method for recording the interference fringes of the image, a conventionally known method can be used. For example, an interference pattern of an image is recorded by bringing the original plate into close contact with the volume hologram forming layer and performing interference exposure from the base film side using ionizing radiation such as visible light, ultraviolet light, or electron beam. Further, in order to accelerate the refractive index modulation and complete the polymerization reaction of the photopolymerizable compound or the like, after the interference exposure, treatments such as full exposure with ultraviolet rays and heating can be appropriately performed.

  The diffraction layer 15 which is a volume hologram layer formed as described above diffracts only light in a specific wavelength region. The wavelength region of the light reflected by the diffraction layer 15 can be adjusted by adjusting the wavelength of the light used during interference fringe recording. Therefore, by adjusting the wavelength region (selected wavelength region) of light reflected (diffracted) by the diffraction layer (transmission type volume hologram layer) 15, the image reproduced by the diffraction layer 15 is visually recognized in a desired color. Can get. As an example, a wavelength region corresponding to the half width of the light reflected by the diffractive layer 15, in other words, securing a light amount that is more than half of the maximum reflected light amount in the light amount distribution with respect to the wavelength of the light reflected (diffracted) by the diffractive layer 15. When the wavelength range that can be set is 520 to 540 nm, the reflected light from the diffraction layer 15 can be visually recognized as a green image.

  Here, the relationship between the wavelength region of light diffracted by the diffraction layer 15 and the wavelength region of light reflected by the reflection layer 12 described above will be described.

  4 to 6 are diagrams for explaining the wavelength region of the light reflected by the diffraction layer 15 and the reflection layer 12. The curve H in FIGS. 4 to 6 shows the distribution of the amount of light according to the wavelength of light reflected (diffracted) by the diffraction layer 15, and the curve C shows the amount of light according to the wavelength of light reflected by the reflection layer 12. Distribution is shown.

  As described above, the wavelength region of light that can be reflected by the reflective layer 12 and the diffraction layer 15 can be adjusted. 4 to 6 show examples in which the selection wavelength range of the reflective layer 12 and the selection wavelength range of the diffraction layer 15 are variously changed. Hereinafter, each example will be described in order.

  First, the example shown in FIG. 4 will be described. Here, the “half width” used earlier will be described first. Taking the diffractive layer 15 shown in FIG. 4 as an example, the half width is the width between wavelengths that is half (A / 2) of the peak value A of the reflected light amount (diffracted light amount). It is a range (half-value width 20 nm). In other words, it is the width of the wavelength region D that has a reflected light amount that is half (A / 2) or more of the peak value A of the reflected light amount in the light amount distribution H with respect to the wavelength of the light reflected by the diffraction layer 15. The light reflected by the diffractive layer 15 includes a lot of light having a wavelength in the wavelength range of 520 to 540 nm corresponding to the half width. For this reason, the reflected light includes light that can be visually recognized as a color other than green, but the reflected light (image reproduced by the diffraction layer 15) is generally recognized as green.

  On the other hand, with respect to the reflective layer 12 in the example shown in FIG. The wavelength region corresponding to the half width is in the range of 480 to 540 nm. As a result, similar to the diffraction layer 15, the light reflected by the reflection layer 12 is recognized as green as a whole.

  Note that the wavelength 540 nm corresponding to the half-value width of the diffraction layer 15 and the wavelength 540 nm corresponding to the half-value width of the reflective layer 12 have the same value, and overlap in FIG. In FIG. 4, the position is intentionally shifted.

  As described above, in the example shown in FIG. 4, the wavelength region corresponding to the half width of the light reflected by the diffraction layer 15 is included in the wavelength region corresponding to the half width of the light reflected by the reflective layer 12. . Therefore, the reflected light of the reflective layer 12 and the reflected light of the diffraction layer 15 are both observed in green, although there is a slight difference in color.

  Next, consider the example shown in FIG.

  In the example shown in FIG. 5, the light quantity distribution H of the light reflected (diffracted) by the diffraction layer 15 is the same as the example shown in FIG. Therefore, the wavelength region corresponding to the half width H is 520 nm to 540 nm.

  On the other hand, for the reflective layer 12 in the example shown in FIG. 5, the wavelength region corresponding to the half width is 605 nm to 675 nm. As a result, unlike the diffraction layer 15, the light reflected by the reflection layer 12 is recognized as red as a whole.

  Thus, in the example shown in FIG. 5, the wavelength region corresponding to the half-value width of the light reflected by the diffraction layer 15 is out of the wavelength region corresponding to the half-value width of the light reflected by the reflective layer 12. There is no overlap. Therefore, the reflected light of the reflective layer 12 and the reflected light of the diffraction layer 15 can be identified as different colors.

  Next, the example shown in FIG. 6 will be described.

  For the diffraction layer 15 of the example shown in FIG. 6, the wavelength region corresponding to the half width is 600 nm to 620 nm. As a result, the light reflected (diffracted) by the diffraction layer 15 is recognized as red as a whole.

  On the other hand, for the reflective layer 12 in the example shown in FIG. 6, the wavelength region corresponding to the half width is 410 nm to 480 nm. As a result, unlike the diffraction layer 15, the light reflected by the reflection layer 12 is recognized as blue as a whole.

  Thus, in the example shown in FIG. 6, the wavelength region corresponding to the half-value width of the light reflected by the diffraction layer 15 is out of the wavelength region corresponding to the half-value width of the light reflected by the reflective layer 12 and is completely overlapped. Not. Therefore, the reflected light of the reflective layer 12 and the reflected light of the diffraction layer 15 can be identified as different colors.

  Further, as well shown in FIG. 6, generally, a cholesteric regular liquid crystal structure has a sharper selection wavelength on the long wavelength side than on the short wavelength side. That is, the light amount distribution C of the reflected light due to the cholesteric liquid crystal structure has a stronger inclination on the long wavelength side than on the short wavelength side. Accordingly, when the wavelength region of the specific light reflected by the reflective layer 12 is on the shorter wavelength side than the wavelength region of the specific light diffracted by the diffraction layer 15 as in the example shown in FIG. As a typical aspect, when the selected center wavelength of the reflective layer 12 is shorter than the selected center wavelength of the diffractive layer 15, the wavelength region of the light reflected by the reflective layer 12 and the light diffracted by the diffractive layer 15 are used. Can be more clearly distinguished. That is, the wavelength region of the specific light reflected by the reflective layer 12 is arranged on the shorter wavelength side than the wavelength region of the specific light reflected by the diffraction layer 15, thereby reflecting the reflective layer 12. The light and the reflected light of the diffraction layer 15 can be identified more clearly as different colors.

  On the other hand, contrary to the example shown in FIG. 6, the wavelength range of the specific light reflected by the reflective layer 12 is longer than the wavelength range of the specific light diffracted by the diffraction layer 15. As a more specific aspect, when the selected center wavelength of the reflective layer 12 is longer than the selected center wavelength of the diffractive layer 15, a part or all of the wavelength region of light reflected by the reflective layer 12, A part or all of the wavelength region of the light diffracted by the diffraction layer 15 can be easily overlapped. In this case, as will be described later, it is possible to easily and surely produce an authenticity display body in which it is extremely difficult to create a counterfeit product.

(About reflectivity)
FIG. 7 is a diagram for explaining the reflection of light from each layer when the selective reflection wavelength regions of the reflection layer 12 and the diffraction layer 15 are overlapped.

  For example, when light of the right polarization component is reflected by the reflection portion 12a of the reflection layer 12 having the cholesteric liquid crystal structure, the light of the left polarization component is not reflected by the reflection portion 12a of the reflection layer 12 having the cholesteric liquid crystal structure. The light passes through the reflective layer 12. That is, the reflecting portion 12a of the reflecting layer 12 having a cholesteric liquid crystal structure reflects at most half of incident light (light ray A) and transmits the remaining light (light ray C). Therefore, when the reflection layer 12 is provided on the observation surface side, more than half of the non-polarized incident light is transmitted without being reflected by the reflection layer 12. A large amount of light (light ray C) can reach the diffraction layer 15 and be diffracted by the diffraction layer 15. Thereby, when the reflective layer 12 is disposed on the observation surface side with respect to the diffraction layer 15, the reflected color (light ray B) reflected by the reflective layer 12 and the image (light ray D) reproduced by the diffraction layer 15 , Both of them can be clearly observed with sufficient brightness.

  Here, as described above, the reflective portion 12a of the reflective layer 12 can form a pattern. And the reflectance as the reflection layer 12 whole can also be adjusted by adjusting the area of the part in which the pattern is formed.

  On the other hand, even when the diffraction layer 15 is disposed on the observation surface side of the reflection layer 12, the reflectance (diffraction efficiency) of the Lippmann hologram is not 100%. Enters the reflective layer 12, and a part of the incident light is reflected by the reflective layer 12. Therefore, also in this case, both the reflected color (light ray B) reflected by the reflective layer 12 and the image (light ray D) reproduced by the diffraction layer 15 can be observed.

(Authenticity determination method, action effect of authenticity indicator)
As described above, the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffraction layer 15 can be adjusted. That is, as shown in FIGS. 5 and 4, the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffraction layer 15 can be overlapped at least partially. Also, as shown in FIG. 4, either one of the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffractive layer 15 can include the other (where one includes the other, It is also included that the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffractive layer 15 coincide). Furthermore, as shown in FIG. 6, the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffractive layer 15 may be completely shifted, that is, not overlapped at all.

  Furthermore, a wavelength region E that has a light quantity more than half of the maximum light quantity B in the light quantity distribution C with respect to the wavelength of the light reflected by the reflective layer 12, and a light quantity distribution H with respect to the wavelength of the light reflected by the diffraction layer 15. One of the wavelength regions D that have a light quantity more than half of the maximum light quantity A can also include the other (wherein one includes the other, the wavelength region D, the wavelength region E, Is also included). Further, in the light amount distribution C with respect to the wavelength of the light reflected by the reflective layer 12, the wavelength region E that has a light amount more than half of the maximum light amount B in the light amount distribution C with respect to the wavelength of the light is It is also possible to deviate from the wavelength region D that has a light quantity that is half or more of the maximum light quantity A.

  In any case, the light reflected by the reflecting portion 12a of the reflecting layer 12 is only one of the right circular deflection component (or the left circular deflection component). Accordingly, when the reflected light from the authentic display body 101 is observed through the circular deflecting plate 50 capable of absorbing the right circular deflection component, the reflected light from the reflecting portion 12a that has been observed so far is observed. Cannot be performed (see FIG. 2B and FIG. 2E). On the other hand, whether or not the light is reflected (diffracted) by the diffraction layer 15 does not depend on the deflection component. Therefore, even if the circular deflection plate 50 is used, an image reproduced by the diffraction layer 15 is passed through the circular deflection plate 50. It can be observed in the same way as when there is no. By performing the determination using such a deflection plate 50, the authenticity of the authenticity display body 101 can be accurately identified.

  Note that when the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffractive layer 15 are completely or partially deviated, the image reproduced by the diffractive layer 15 and the reflection of the reflective layer 12 are reflected. The light reflected by the portion 12a can be visually recognized with different colors. In this case, the presence or absence of the reflected light from the reflection part 12a of the reflection layer 12 can be determined clearly.

  In addition, as described above, it is useful that the reflective portion 12a of the reflective layer 12 forms a pattern. In this case, since the reflected light from the reflection part 12a of the reflection layer 12 can be visually recognized as a pattern, the presence or absence of the reflection light from the reflection part 12a of the reflection layer 12 can be determined clearly.

  Furthermore, the relief hologram can switch the image by moving the viewpoint in the left-right direction, whereas the diffraction layer 15 can switch the image by moving the viewpoint in two directions, the left-right direction and the up-down direction. Therefore, it is possible to reproduce a three-dimensional image or a deep image.

  Further, as shown in FIG. 2D, when the selected wavelength region of the reflective layer 12 and the selected wavelength region of the diffractive layer 15 overlap at least partially, an image reproduced by the diffractive layer 15 can be visually recognized. At the same time, the light reflected by the reflecting portion 12a of the reflecting layer 12 can be visually recognized. Therefore, if the volume hologram forming the diffractive layer 15 is forged using this authentic display as an original, light reflected by the reflecting portion 12a of the reflecting layer 12 is also recorded in the forged product. Such a counterfeit product can be easily and reliably determined to be a counterfeit product by the determination method using the circular deflection plate 50 described above.

  Furthermore, the diffraction layer 15 made of a volume hologram layer requires advanced technology and special equipment for its production and replication, and the material used is also special, and its distribution is managed. Therefore, the diffraction layer 15 is difficult to counterfeit.

  In addition, since the reflective layer 12 and the diffractive layer 15 are laminated to form the authentic display body 101 integrated, the pasting operation is easy. In addition, when authenticity is determined, authenticity determination using both the reflective layer 12 and the diffractive layer 15 is possible, and the effect of preventing forgery can be further enhanced.

(Modification)
Various modifications and changes can be made to the above embodiment.

(1) In the above-described embodiment, an example in which chiral nematic liquid crystal is used as the reflective layer 12 having a cholesteric regular structure has been described. However, the present invention is not limited thereto, and for example, cholesteric liquid crystal or the like may be used. Moreover, you may produce the reflection layer 12 using the composition which can form another helical structure area | region.

(2) In the above-described embodiment, the example in which the reflection portion 12a of the reflection layer 12 is arranged so as to form a lattice pattern is shown, but the present invention is not limited to this. For example, the reflective portion 12a of the reflective layer 12 may be patterned so as to form characters, patterns, etc., thereby improving the design. Further, as described above, only a part of the reflection portion 12a of the reflection layer 12 may be in the planar alignment state. In this case, the planar alignment region or other region may be patterned so as to form a character or a pattern.
In addition, as a method of patterning the reflection part 12a of the reflection layer 12, the method disclosed by Unexamined-Japanese-Patent No. 2004-133179 can be used, for example.
Further, the reflective layer 12 may be provided by adjusting the reflectance by changing the thickness or the number of spiral pitches. On the other hand, you may form the reflection layer 12 in the whole surface of the layer used as a support base material. In this case, it is useful to adjust the reflectance of the reflective layer 12 by changing the thickness of the layer and the number of spiral pitches.

(3) In the above-described embodiment, a primer layer formed by applying a primer may be further provided between the layers of the authenticity display body. By providing the primer layer, the adhesion between the layers can be improved. Further, another heat seal layer may be provided between the heat seal layer 23 and the object in order to improve the adhesion with the object.

(4) In the above-described embodiment, the example in which the second adhesive layer 16 and the base material layer 17 are provided on the back surface side of the diffraction layer 15 has been described. However, the present invention is not limited thereto, and an easy-adhesion PET layer may be provided. .

(5) In the above-described embodiment, a barrier layer may be provided on the back side (the side opposite to the observation surface side) from the diffraction layer 15. Depending on the combination of the resin composition forming the diffraction layer 15, the separator, the heat seal layer, etc., the low molecular weight component migrated from the diffraction layer 15 to other layers over time, and this was recorded due to this. In some cases, the peak wavelength of the hologram shifts to the blue side (short wavelength side), or when the hologram shifts to a separator or the like, its peelability may be changed. Therefore, by providing a barrier layer, these obstruction factors may be eliminated, and the durability as an authentic display body may be improved.
The material that can be used as such a barrier layer is not particularly limited as long as it is a material that exhibits its barrier properties, but the object can usually be achieved by using a transparent organic resin material. Among them, a solvent-free trifunctional or higher functional group, preferably a hexafunctional or higher functional ionizing radiation curable epoxy-modified acrylate resin, urethane-modified acrylate resin, acrylic-modified polyester resin, etc. that reacts with ionizing radiation such as ultraviolet rays and electron beams is used. Can do. In particular, urethane-modified acrylate resins are preferably used because of their high barrier properties.
Further, as these ionizing radiation curable resins, those having a molecular weight in the range of 500 to 2,000 are preferably used in consideration of coating suitability, hardness of the finally obtained barrier layer, and the like. Moreover, since the coating of the barrier layer is basically a solventless system, it can be laminated on any layer of the diffraction layer, the separator, and the heat seal layer. Moreover, when the adhesiveness of each layer is weak, the layer etc. which have the function to improve adhesiveness may be formed.

(6) In the above-described embodiment, an example in which a reflective volume hologram is used as the volume hologram forming the diffraction layer 15 has been described, but the present invention is not limited thereto. As the volume hologram forming the diffraction layer 15, a transmission volume hologram may be used. In this case, by providing a separate reflection layer on the back side of the transmission type volume hologram, the image recorded on the transmission type volume hologram can be visually recognized as light reflected by the separate reflection layer. In addition, as a separate reflection layer, a well-known layer can be used, for example, a cholesteric liquid crystal layer can also be used. Further, this separate reflective layer does not need to have transparency.

(Example)
Hereinafter, the authenticity display according to the present invention will be described in detail with reference to specific examples.

Example 1
Example 1 of the authenticity display body 101 described below is an embodiment shown in FIG. Hereinafter, layers other than the reflective layer 12 and the diffraction layer 15 of the authentic display body 101 shown in FIG. 1 will be described in detail. As described above, the authenticity display body 101 according to the first embodiment can be used as a label that can be easily attached to an object.

  The authentic display body 101 includes a protective layer 11, a reflective layer 12, a support base layer (adhesive PET layer) 13, a first adhesive layer 14, a diffraction layer 15, a first layer, from the observation surface 5 side to the back surface 6 side. 2 Adhesive layer 16, base material layer (black PET layer) 17, third adhesive layer (adhesive layer) 18, and fourth separator 19 are laminated in this order.

  The protective layer 11 is a layer that protects the surface of the authentic display body 101 and is laminated on the observation surface side most. Since the protective layer 11 is substantially transparent, the reflected light reflected by the cholesteric liquid crystal layer 12 and the image reproduced by the diffraction layer 15 can be visually observed through the protective layer 11 to determine authenticity. . Since the protective layer 11 needs to exhibit the polarization separation function of the reflective layer 12 without disturbing the polarization of incident light from the observation surface side, it is desirable to use a material with low birefringence. For example, a film made of TAC (triacetyl cellulose), a polycarbonate polymer, a cycloolefin polymer, or the like can be used.

  Further, as the protective layer 11, for example, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, polymethacrylate resin, polyvinyl chloride resin, cellulose resin, silicone resin, chlorinated rubber, casein, various surfactants. In general, curable resins such as resins prepared by mixing one or more of metal oxides, ionizing radiation curable resins that react with ultraviolet rays, electron beams, and thermosetting resins are known. You may use what was apply | coated by the method.

  The support base material layer 13 is an easy-adhesion PET layer having easy adhesion formed of polyethylene terephthalate (PET), and serves as a support base material for the reflective layer 12. This support base material layer 13 is substantially transparent. As the support substrate for the reflective layer 12, polycarbonate polymer, polyester polymer such as polyethylene terephthalate, polyimide polymer, polysulfone polymer, polyethersulfone polymer, polystyrene polymer, polyethylene and polypropylene. Film made of thermoplastic polymer such as polyolefin polymer, polyvinyl alcohol polymer, cellulose acetate polymer, polyvinyl chloride polymer, polyacrylate polymer, polymethyl methacrylate polymer, etc. be able to.

  In addition, when laminating the reflective layer 12 on the support base material layer 13, as described above, after applying a liquid crystalline composition having a cholesteric regular structure, it is generally performed an alignment treatment and a curing treatment. Is. At this time, if the reflective layer 12 is made diffusive, it is necessary to control the cholesteric liquid crystal structure not to be in the planar alignment state. In this case, it is preferable to use the support base layer 13 that does not have alignment ability on the surface on which the liquid crystalline composition is applied. However, even if the material on the surface of the support base layer 13 on which the liquid crystalline composition is applied has a surface orientation ability such as a stretched film, the support base layer 13 The surface of the stretched film as a surface is subjected to surface treatment, the material of the liquid crystalline composition, the process conditions for aligning the liquid crystalline composition, or the like is controlled, whereby the cholesteric liquid crystal structure of the reflective layer 12 is obtained. It is also possible to control so as not to be in the planar alignment state.

  In addition, when the surface of the support base material layer 13 on which the liquid crystal composition is applied has orientation ability, an intermediate layer such as an easy adhesion layer is provided between the reflective layer 12 and the support base material layer 13. By providing a layer, it is possible to control the alignment state of the cholesteric liquid crystal structure so that the directors of the liquid crystal molecules in the vicinity of the interface with the intermediate layer in the cholesteric liquid crystal structure are directed in a plurality of directions. In addition, when providing intermediate | middle layers, such as an easily bonding layer, the adhesiveness between the reflective layer 12 and the support base material layer 13 can also be improved. In addition, as such an intermediate | middle layer, what is necessary is just to be able to acquire high adhesiveness with respect to both the material of the reflection layer 12, and the material of the support base material layer 13, and generally using what is marketed can be used. it can. Specifically, for example, PET film A4100 with an easy-adhesion layer manufactured by Toyobo Co., Ltd., and easy-adhesive materials AC-X, AC-L, and AC-W manufactured by Panac Co., Ltd. may be used.

  The first adhesive layer 14 is substantially transparent and is a layer formed by applying an adhesive. In this embodiment, the pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive, but may be a heat-seal layer using a heat seal that exhibits adhesiveness when heated and pressurized. The second adhesive layer 16 is a layer formed by applying an adhesive. The base material layer 17 has a diffraction layer 15 formed on the observation surface side through an adhesive layer 16. In the present embodiment, it is made of black polyethylene terephthalate (PET), which removes the surface reflection of the object and improves the visual contrast to make the image easier to see. The 3rd adhesion layer 18 is a layer formed by apply | coating an adhesive, and is a sticking layer which can stick the authenticity display body 101 to a target object easily. The fourth separator 19 is a peelable peeling member laminated on the back side of the third adhesive layer 18.

  FIG. 8 is a diagram illustrating a method of manufacturing the authentic display body according to the first embodiment. The authentic display body 101 of Example 1 is formed by stacking the stacked body S1 to the stacked body S6. Hereinafter, each laminate will be described.

  The stacked body S1 is formed by stacking the protective layer 11, the reflective layer 12, and the support base material layer 13. First, after drying the cholesteric liquid crystal solution prepared as described below on the easy-adhesion surface of the easy-adhesion PET film (Cosmo Shine A4100 (50 μm); manufactured by Toyobo Co., Ltd.), which is the support base layer 13, with a bar coater. After coating so that the film thickness was 1.6 μm, the film was heated in an oven at 80 ° C. and subjected to orientation treatment (drying treatment).

(Cholesteric liquid crystal solution)
・ Main ingredient consisting of UV curable nematic liquid crystal: 95.8 parts by weight ・ Polymerizable chiral agent: 4.2 parts by weight ・ Photopolymerization initiator (manufactured by Ciba Specialty Chemicals): 5 parts by weight A solution in which a polymerizable chiral agent and a photopolymerization initiator were added to was dissolved in cyclohexanone to obtain a cholesteric liquid crystal solution.

Thereafter, the reflective layer 12 was irradiated with 3000 mJ / cm ² of ultraviolet light at 3000 mJ / cm ^{2 in} a nitrogen atmosphere to cure the reflective layer 12 to obtain the reflective layer 12 / supporting substrate layer 13 having a reflective center wavelength at 510 nm. . A protective layer solution having the following composition was applied on the reflective layer 12 of the reflective layer 12 / support base layer 13 thus obtained by a bar coater so that the film thickness after drying was 2 μm, and was heated to 80 ° C. Was dried in an oven to obtain a laminate S1.

(Protective layer solution)
Polymethyl methacrylate (weight average molecular weight 100,000): 100 parts by weight Methyl ethyl ketone: 400 parts by weight The laminate S2 includes a first untreated PET layer 41, a diffraction layer 15 composed of a volume hologram layer, and a second untreated PET. The layer 42 is formed by laminating. Using a volume hologram recording solution having the following composition on the second untreated PET layer 42 (Lumirror T60 (50 μm); manufactured by Toray Industries, Inc.) using an applicator so that the film thickness after drying becomes 10 μm. Applied. Thereafter, the applied volume hologram recording solution was dried in an oven at 90 ° C. to obtain a volume hologram recording layer / second untreated PET layer 42. The volume hologram recording layer surface of the obtained laminate is brought into close contact with the hologram master, and laser light (532 nm) is incident at 80 mJ / cm ² from the second untreated PET layer side, and the hologram is incident on the volume hologram recording layer. An image was recorded and a diffraction layer 15 was formed. Thereafter, the laminate including the diffractive layer 15 was peeled off from the hologram original plate, and the first untreated PET layer 41 (Lumirror T60 (50 μm)) was laminated on the diffractive layer 15 of the laminate. Thereafter, the laminate was subjected to a heat treatment and an ultraviolet fixing exposure treatment to obtain a laminate S2 having a reflection center wavelength at 530 nm.

(Volume type hologram recording solution)
Polymethyl methacrylate (weight average molecular weight 200,000): 100 parts by weight 9,9-bis (4-acryloxydiethoxyphenyl) fluorene: 80 parts by weight 1,6-hexanediol diglycidyl ether: 70 parts by weight Diphenyliodonium hexafluoroantimonate: 5 parts by weight3,9-diethyl-3'-carboxymethyl-2,2'-thiacarbocyanine iodonium salt: 1 part by weightSolvent (methyl ethyl ketone / 1-butanol = 1/1 (Weight ratio)): 200 parts by weight The laminate S3 is formed by laminating the first separator 43, the first adhesive layer 14, and the second separator 44. An adhesive layer solution having the following composition was applied on the second separator 44 (SPPET (50 μm); manufactured by Tosero Co., Ltd.) using an applicator so that the film thickness after drying was 20 μm. Thereafter, the second separator 44 and the adhesive layer solution were dried in an oven at 100 ° C. to obtain the first adhesive layer 14 / the second separator 44. Next, the 1st separator 43 (SPPET (38 micrometers); Tosero Co., Ltd. product) was laminated on the 1st adhesion layer 14 side of the 1st adhesion layer 14 / the 2nd separator 44, and layered product S3 was obtained. The 1st separator 43 and the 2nd separator 44 which were used here used the thing from which peeling force differs.

(Adhesive layer solution)
・ Acrylic adhesive (Nissetsu PE-118; manufactured by Nippon Carbide Industries Co., Ltd.): 100 parts by weight ・ Isocyanate-based crosslinking agent (Nissetsu CK-101; manufactured by Nippon Carbide Industries Co., Ltd .: 2 parts by weight) ・ Solvent (methyl ethyl ketone) / Toluene / ethyl acetate = 2/1/1 (weight ratio)): 60 parts by weight The laminate S4 includes a third separator 45, a second adhesive layer 16, a base material layer (black PET layer) 17, and a third adhesive layer. (Attachment layer) 18 and the fourth separator 19 are formed by laminating the first adhesive on the black PET film (Lumirror X30 (75 μm); manufactured by Toray Industries, Inc.) as the base material layer 17. The same adhesive layer solution used in layer 14 was applied using an applicator so that the film thickness after drying was 25 μm, and then the base material layer 17 and the adhesive layer solution were placed in an oven at 100 ° C. And dried to obtain a second adhesive layer 16 / base material layer 17. Thereafter, a third separator 45 (SPPET (38 μm); Co., Ltd.) was obtained to obtain a third separator 45, a second adhesive layer 16, and a base material layer 17. Thereafter, the other surface of the base material layer 17 was subjected to a third adhesive layer by a similar method. 18 (use the same solution as the first adhesive layer 14) was formed, and a fourth separator 19 (SPPET (38 μm); manufactured by Tosero Co., Ltd.) was laminated to obtain a laminate S4.

  The authenticity display body 101 of Example 1 is formed as follows using these stacked bodies S1 to S4.

  The first untreated PET layer 41 of the laminate S2 (first untreated PET layer 41 / diffraction layer 15 / second untreated PET layer 42) and the laminate S3 (first separator 43 / first adhesive layer 14 / first The second separator 44 of the second separator 44 is peeled off, and the diffraction layer 15 surface and the first adhesive layer 14 surface of the laminate S2 are laminated facing each other to laminate the laminate S5 (first separator 43 / first adhesive layer 14 / Diffraction layer 15 / second untreated PET layer 42) was obtained. Thereafter, the second untreated PET layer 42 of the laminate S5 and the third separator 45 of the laminate S4 (third separator 45 / second adhesive layer 16 / base material layer 17 / third adhesive layer 18 / fourth separator 19). And the laminate S5 (the first separator 43 / first adhesive layer 14 / diffractive layer 15 / first layer) is laminated by laminating the diffraction layer 15 surface of the laminate S5 and the second adhesive layer 16 surface of the laminate S4 facing each other. 2 adhesive layer 16 / base material layer 17 / third adhesive layer 18 / fourth separator 19) was obtained. Next, the 1st separator 43 of laminated body S6 is peeled, and the 1st adhesive 14 surface of laminated body S6 and the support base material layer 13 of laminated body S1 (protective layer 11 / reflection layer 12 / support base material layer 13). The authentic display body 101 was obtained by laminating the surfaces facing each other.

  According to the first embodiment, the authenticity display body 101 can be used as a label having a function of displaying authenticity by the reflective layer 12 and a function of displaying authenticity by the diffraction layer 15. Moreover, since the authenticity display body 101 can be provided as a label, it can be used by being easily attached to various objects.

  Since the reflection layer 12 is provided closer to the observation surface than the diffraction layer 15, it can be provided so as to prevent replication at a laser light source and an incident angle that match the replication conditions of the diffraction layer 15. For example, when the diffraction layer 15 is a hologram (green) that can be duplicated at an incident angle of 30 °, if the reflective layer 12 that reflects light at an incident angle of 30 ° is provided, the reflected light of the reflective layer 12 is also recorded. Therefore, the diffraction layer 15 cannot be duplicated.

  In addition, the reflective layer 12 has a phase difference at an oblique incidence regardless of the reproduction wavelength, and by increasing the thickness of the reflective layer 12, the light between the light incident on the diffraction layer 15 and the light reflected from the diffraction layer 15 is increased. The resulting phase difference can be increased. This produces an effect of making it difficult to replicate because a phase difference occurs even when the reproduction incident light from a specific angle is not reflected by the reflection layer 12.

  Furthermore, when replication is attempted with linearly polarized light, the incident light that is angled from the normal line has the reflective layer 12 functioning as a phase shifter, and the phase of the incident light is shifted. Furthermore, the light diffracted by the diffraction layer 15 is out of phase again when passing through the reflective layer 12. For example, when the phase is shifted by λ / 10 or more, replication becomes difficult. When the phase is λ / 2, the phase is inverted, so that no interference occurs. Therefore, duplication can be prevented.

  In addition, a part of the incident light incident on the cholesteric reflecting surface is reflected in the first place, so that an image of the reflecting layer 12 is recorded. Therefore, in the duplicated hologram, the reflection component by the reflection layer 12 is recorded in addition to the desired image. For this reason, such a duplicate product can be determined as a counterfeit product by authenticity determination using the circular deflection plate described above. That is, an authentic display that is more difficult to counterfeit can be obtained.

(Example 2)
FIG. 9 is a diagram showing a layer configuration of Example 2 of the embodiment of the authenticity display according to the present invention. The authenticity display body 102 according to the second embodiment can be used as a label that can be easily attached to an object.

  In the authentic display 102 of Example 2, the protective layer 11, the reflective layer 12, the support base layer (double-sided easy-adhesion PET layer) 20, the diffractive layer 15, and the second layer are arranged from the observation surface 5 side to the back surface 6 side. The adhesive layer 16, the base material layer (black PET layer) 17, the third adhesive layer 3 (sticking layer) 18, and the fourth separator 19 are laminated in this order.

  FIG. 10 is a diagram illustrating a method of manufacturing the authentic display body according to the second embodiment.

  The authenticity display body 102 of Example 2 is formed as follows using the stacked body S4 and the stacked body S7.

  The stacked body S7 is formed by stacking the protective layer 11, the reflective layer 12, and the support base material layer 20. This laminated body S7 is substantially the same as the laminated body S1 shown in Example 1, but the double-sided easy-adhesive PET film (Cosmo Shine A4300 (50 μm); It is different in that it is used. In place of the first untreated PET layer 41 to be laminated when the laminate S2 shown in Example 1 is produced, the laminate 20 is laminated with the support base material layer 20 surface and the diffraction layer 15 surface facing each other. A laminate S8 (protective layer 11 / reflective layer 12 / support base layer 20 / diffraction layer 15 / second untreated PET layer 42) was obtained in the same manner except for the above. Thereafter, the second untreated PET layer 42 of the laminate S8 and the third separator 45 of the laminate S4 are peeled, and the diffraction layer 15 surface of the laminate S8 and the second adhesive layer 16 surface of the laminate S4 are faced to laminate. By doing so, an authentic display 102 was obtained.

  In Example 2, although the double-sided easy-adhesion PET film was used as the support base material layer 20 and the diffraction layer 15 was provided directly on the back surface side of the support base material layer 20, the present invention is not limited thereto. An easy-adhesive PET film may be used as the layer 20, and a substantially transparent adhesive may be applied between the easy-adhesive PET film and the diffraction layer 15 to form an adhesive layer, and the diffraction layer 15 may be provided.

(Example 3)
FIG. 11 is a diagram showing a layer configuration of Example 3 of the embodiment of the authenticity display according to the present invention.

  The authentic display body 103 of Example 3 includes the third untreated PET layer 21, the peelable protective layer 22, the reflective layer 12, the diffraction layer 15, and the heat seal layer 23 from the observation surface 5 side to the back surface 6 side. They are stacked in order. The authenticity display body 103 according to the third embodiment uses the reflective layer 12 and the diffraction layer 15 by transferring them to an object.

  The third untreated PET layer 21 is a layer that is laminated on the most observed surface side, but is peeled off after thermal transfer.

  The peelable protective layer 22 is a layer that allows the third untreated PET layer 21 to be easily peeled when the reflective layer 12 and the diffractive layer 15 are transferred onto an object. For example, an acrylic resin 1 or 2 from vinyl chloride-vinyl acetate copolymer resin, polyester resin, polymethacrylate resin, polyvinyl chloride resin, cellulose resin, silicone resin, chlorinated rubber, casein, various surfactants, metal oxides, etc. What mixed the seed | species or more can be used. Among them, an acrylic resin having a molecular weight of about 20,000 to 100,000 is composed of an acrylic resin alone or an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin having a molecular weight of 8000 to 20000. Further, a polyester resin having a molecular weight of 1000 to 5000 is used as an additive. It is particularly preferable that the composition comprises ˜5% by weight.

  The heat seal layer 23 is a layer formed on the most back surface side, and when the reflective layer 12 and the diffraction layer 15 are transferred to an object by thermal transfer, they are brought into close contact with each other and heated, so that the diffraction layer 15 and the object are heated. And glue. Therefore, the heat seal layer 23 has a function as an adhesive layer that allows the authenticity display body 103 to be attached to an object.

  Examples of such a heat seal layer 23 include ethylene-vinyl acetate copolymer resin (EVA), polyamide resin, polyester resin, polyethylene resin, ethylene-isobutyl acrylate copolymer resin, butyral resin, polyvinyl acetate, and copolymer thereof. Combined resin, cellulose resin, polymethyl methacrylate resin, polyvinyl ether resin, polyurethane resin, polycarbonate resin, polypropylene resin, epoxy resin, phenol resin, styrene butadiene styrene block copolymer (SBS), styrene isoprene styrene block copolymer (SIS), styrene ethylene butylene styrene block copolymer (SEBS), styrene ethylene propylene styrene block copolymer (SEPS) and other thermoplastic resins can be used. . Among these, a layer that can be heat-sealed at a temperature of 180 ° C. or lower is preferable, and an ethylene-vinyl acetate copolymer resin (EVA) having an acetic acid content of 25% or more is preferably used. Moreover, the heat sealing layer may be colored to the resin as necessary.

  FIG. 12 is a diagram illustrating a method of manufacturing the authentic display body according to the third embodiment.

  The authenticity display body 103 of Example 3 is formed as follows using the stacked body S9.

  The laminate S9 is formed by laminating the third untreated PET layer 21, the peelable protective layer 22, and the reflective layer 12. First, on a third untreated PET layer 21 (Lumirror T60 (25 μm); manufactured by Toray Industries, Inc.), a peelable protective layer solution having the following composition is dried to 1 μm with a bar coater. It was applied to.

(Peelable protective layer solution)
Polymethylmethacrylate (weight average molecular weight 100,000): 97 parts by weight Polyethylene wax (weight average molecular weight 10,000, average particle size 5 μm): 3 parts by weight Solvent (methyl ethyl ketone / toluene = 1/1 (weight ratio) ): 400 parts by weight Thereafter, the film was dried in an oven at 100 ° C. to obtain a third untreated PET layer 21 / peelable protective layer 22. Next, the cholesteric liquid crystal solution used in the laminate S1 is applied on the peelable protective layer 22 by a bar coater so as to have a dried film thickness of 1.6 μm, and then heated in an oven at 80 ° C. for orientation treatment (drying). Treatment) and curing treatment (for example, ultraviolet curing treatment), and a laminate S9 was obtained.

  Next, a stacked body S10 was manufactured in the same manner as the stacked body S2. However, in the production of the laminated body S10, instead of laminating the diffraction layer and the first untreated PET layer 41 in the production of the laminated body S2, the surface of the diffraction layer 15 and the reflective layer 12 surface of the laminated body S9 are used. Laminated face to face. As a result, a laminate S10 (third untreated PET layer 21 / peelable protective layer 22 / reflective layer 12 / diffraction layer 15 / second untreated PET layer 42) was obtained. Thereafter, the second untreated PET layer 42 of the laminate S10 was peeled from the other parts of the laminate S10. Next, a heat seal layer solution having the following composition is applied on the surface of the diffraction layer 15 with a bar coater so that the film thickness after drying is 4 μm, and then the laminate is dried in an oven at 100 ° C. for authenticity. A sex display 103 was obtained.

(Heat seal layer solution)
Polyester resin (Vylonal MD1985; manufactured by Toyobo Co., Ltd.): 100 parts by weight Solvent (water / isopropyl alcohol = 1/1 (weight ratio)): 100 parts by weight According to Example 3, the authentic display 103 Can be used as a transfer foil having a function of displaying authenticity because the number of layers to be laminated is small, the thickness is thinly laminated, and the heat seal layer 23 can be applied to an object. Further, since the third untreated PET layer 21 laminated on the most observation surface side is peeled off after the thermal transfer, it does not remain on the authentic display body after the transfer.

  In Example 3, a primer layer may be formed between the reflective layer 12 and the diffraction layer 15.

  Further, in Example 3, the third untreated PET layer 21 laminated on the most observation surface side can be peeled off after being attached to the object. In this case, the outermost surface of the authentic display body 103 is the peelable protective layer 22. Therefore, although the 3rd untreated PET layer 21 is laminated | stacked on the observation surface side rather than the reflection layer 12, the member which has birefringence can also be used.

Example 4
Next, Example 4 will be described. In Example 4, the authenticity display body which can be used as a label which can be easily attached to an object is shown.

  Note that, in the authentic display described as Example 6 to be described later from Example 4, the diffractive layer 15 is disposed closer to the observation surface 5 than the reflective layer 12. As described above, also in the authentic displays of Examples 4 to 6, both the image reproduced by the diffraction layer 15 by the reflected light and the reflected color from the reflected light of the reflective layer 12 are clear. It can be visually observed, is difficult to counterfeit, and can be used as an authentic display with high designability and discrimination.

  FIG. 13 shows the layer structure of Example 4 of the authenticity display body.

  The authentic display body 104 of Example 4 has a third untreated PET layer 21, a peelable protective layer 22, a diffraction layer 15, a first adhesive layer 14, and a reflective layer 12 from the observation surface 5 side to the back surface 6 side. , A support base material layer (easy adhesion PET layer) 13, a first adhesive layer (sticking layer) 24, and a second separator 25 are laminated in this order.

  FIG. 14 is a diagram illustrating a method of manufacturing the authenticity display body according to the fourth embodiment. As shown in FIG. 14, this authentic display body 104 could be formed as follows using the stacked body S11 and the stacked body S12. The laminate S11 is formed by laminating the third untreated PET layer 21, the peelable protective layer 22, the diffraction layer 15, and the second untreated PET layer 42. First, as described in the method for producing the laminate S9 in Example 3, a laminate of the third untreated PET layer 21 / peelable protective layer 22 was obtained. Further, in the same manner as in Example 1 in which the diffraction layer 15 / second untreated PET layer 42 was obtained from the laminate S2, a laminate of diffraction layer 15 / second untreated PET layer 42 was obtained. Next, the obtained laminate (third untreated PET layer 21 / peelable protective layer 22) and laminate (diffraction layer 15 / second untreated PET layer 42) were separated from the peelable protective layer 22 surface and the diffraction layer. The laminate was heat laminated at 80 ° C. so that the 15 surfaces faced to obtain a laminate S11.

  The laminate S12 is formed by laminating the second separator 44, the first adhesive layer 14, the reflective layer 12, the support base material layer (easily adhesive PET layer) 13, the first adhesive layer 24, and the second separator 25. Has been. This laminated body S12 is formed using the laminated body S1 shown in Example 1 and the two laminated bodies S3.

  First, as described in the production method of the laminate S1 in Example 1, a laminate of the reflective layer 12 / supporting base material layer 13 was obtained. Next, the first adhesive layer 14 of the laminate S3 from which the first separator 43 has been peeled off and the reflective layer 12 of the laminate (reflecting layer 12 / supporting substrate layer 13) obtained above are laminated facing each other. Furthermore, the laminated body S3 from which the first separator 43 was peeled was similarly laminated on the surface of the supporting base material layer 13 to obtain a laminated body S12.

  The second untreated PET layer 42 of the laminated body S11 and the second separator 44 of the laminated body S12 are peeled off, and the diffractive layer 15 surface and the first adhesive layer 14 surface are laminated facing each other, whereby an authentic display body 104 is obtained. Is obtained. Here, in Example 4, although the example which uses the 1st adhesion layer 24 as a sticking layer was shown, you may use the heat seal layer 23. FIG.

  According to the fourth embodiment, since the diffraction layer 15 is provided on the observation surface side (light incident side) with respect to the reflection layer 12, there is a possibility that the diffraction layer 15 is duplicated. The polarization function is difficult to replicate. Therefore, when viewed through the circularly polarizing plate, the appearance of the reflected light from the reflective layer 12 does not change, and only the function of the reflective layer 12 that has been lost can be replicated. For this reason, even if it is counterfeited, its authenticity can be easily determined.

  Moreover, since the diffraction efficiency of the diffraction layer 15 is not 100%, the light transmitted through the diffraction layer 15 is reflected by the reflection layer 12. Therefore, when a counterfeit product is duplicated using this authentic display as an original plate, the reflection component from the reflective layer 12 is recorded on the counterfeit product. Therefore, it is possible to obtain an authentic display that is more difficult to forge.

(Example 5)
In Example 5, the authenticity display body which can be used as a label which can be easily attached to an object is shown.

  FIG. 15 is a diagram illustrating a layer configuration of an authenticity display body according to the fifth embodiment.

  The authenticity display body 105 of Example 5 includes a protective layer 11, a diffraction layer 15, a support base layer (easily adhesive PET layer) 13, a reflection layer 12, and a support base material from the observation surface 5 side to the back surface 6 side. A layer (easy adhesion PET layer) 13, a third adhesive layer (sticking layer) 18, and a fourth separator 19 are laminated in this order. Moreover, the support base material layer 13 can be used as an authentic display body without disturbing the polarization function of the reflective layer 12 by using a thin film. Further, two support base material layers 13 may be stacked to make the anisotropic direction orthogonal, thereby suppressing the birefringence effect of the support base material layer 13 on the reflective layer 12.

(Example 6)
Example 6 shown below is thinner than Examples 4 and 5, and shows a layer structure of an authentic display that can be used by transferring to an object.

  FIG. 16 is a diagram illustrating a layer configuration of an authenticity display body according to the sixth embodiment.

  The authenticity display body 106 of Example 6 includes the third untreated PET layer 21, the peelable protective layer 22, the diffraction layer 15, the reflective layer 12, and the heat seal layer 23 from the observation surface 5 side to the back surface 6 side. They are stacked in order. For the production of the authentic display 106, first, the second untreated PET film 42 of the laminate S11 shown in Example 4 is peeled off, and the cholesteric reflective layer solution used in the laminate S1 is applied to the diffraction layer 15 in the same manner. The reflective layer 12 is formed by coating by a method. Further, the heat seal layer solution used in the authentic display body 103 is applied from above by the same method to form the heat seal layer 23, and the authentic display body 106 is obtained. The third untreated PET film 21 on the most observed surface side is peeled off after the authentic display body 106 is thermally transferred to the object, and therefore does not remain after the transfer.

(Example 7)
As Example 7, an authentic display body in which the reflection wavelength region of the reflective layer 15 of the authentic display bodies of Examples 1 to 6 described above was changed was manufactured. In Example 7, in the production of the reflective layer, a cholesteric liquid crystal solution was applied onto a PET film so that the film thickness after drying was 4 μm. In addition, the reflection center wavelength of the reflective layer 12 was set to 640 nm and the half width was set to 70 nm. As a result, according to the authenticity display body according to Example 7, since the wavelength regions of the light reflected by the reflective layer 12 and the diffraction layer 15 are different, the visibility of both reflected lights can be improved. It was. Further, since the appearance of the reflected light from the reflective layer 12 is clearly different by passing the circular deflecting plate 50, the authenticity of the authenticity display body can be easily and accurately determined.

FIG. 1 is a layer configuration diagram showing an example of an embodiment of an authenticity display body according to the present invention. FIG. 2 is a diagram showing the reflective layer and the diffractive layer viewed from the observation surface side. FIG. 3A is a diagram for explaining a cholesteric liquid crystal structure. FIG. 3B is a diagram for explaining a cholesteric liquid crystal structure. FIG. 4 is a diagram illustrating an example of a light amount distribution related to the wavelength of light reflected by the reflective layer and a light amount distribution related to the wavelength of light reflected by the diffraction layer. FIG. 5 is a diagram illustrating another example of the light amount distribution regarding the wavelength of light reflected by the reflective layer and the light amount distribution regarding the wavelength of light reflected by the diffraction layer. FIG. 6 is a diagram illustrating still another example of the light amount distribution related to the wavelength of light reflected by the reflective layer and the light amount distribution related to the wavelength of light reflected by the diffraction layer. FIG. 7 is a diagram for explaining the reflection action by the reflection layer and the reflection action by the diffraction layer. FIG. 8 is a diagram showing a method of manufacturing the authenticity display body of the first embodiment shown in FIG. FIG. 9 is a layer configuration diagram showing an authenticity display according to the second embodiment. FIG. 10 is a diagram showing a method of manufacturing the authenticity display body of the second embodiment shown in FIG. FIG. 11 is a layer configuration diagram showing an authenticity display according to the third embodiment. FIG. 12 is a diagram showing a method for manufacturing the authenticity display body of the third embodiment shown in FIG. FIG. 13 is a layer configuration diagram showing an authenticity display according to the fourth embodiment. FIG. 14 is a diagram showing a method for manufacturing the authenticity display body of the fourth embodiment shown in FIG. FIG. 15 is a layer configuration diagram showing an authenticity display body according to the fifth embodiment. FIG. 16 is a layer configuration diagram showing an authenticity display body according to the sixth embodiment.

Explanation of symbols

5 Observation surface 6 Back surface 11 Protective layer 12 Reflective layer (liquid crystal layer, cholesteric liquid crystal layer)
12a Reflector (reflective area)
12b Transmission part (transmission area)
13 Support base layer 14 First adhesive layer 15 Diffraction layer (hologram layer, volume hologram layer)
16 2nd adhesion layer 17 Base material layer 18 3rd adhesion layer (sticking layer)
19 Fourth separator (peeling member)
101, 102, 103, 104, 105, 106 Authentic display

Claims (10)

In the sheet-like authenticity display body which is made to be able to judge the authenticity by observing the reflected light,
A reflective layer having a cholesteric regular liquid crystal structure and including a reflective part that reflects specific light;
It consists of a volume hologram and has a diffraction layer that diffracts specific light,
More than half of the maximum light amount in the light amount distribution with respect to the wavelength of the light diffracted by the diffraction layer in the wavelength region that has a light amount of more than half of the maximum light amount in the light amount distribution with respect to the wavelength of the light reflected by the reflective layer An authenticity display body characterized by including a wavelength region that has a light quantity of. In the sheet-like authenticity display body which is made to be able to judge the authenticity by observing the reflected light,
A reflective layer having a cholesteric regular liquid crystal structure and including a reflective part that reflects specific light;
It consists of a volume hologram and has a diffraction layer that diffracts specific light,
Wherein the wavelength region of specific light reflected by the reflective layer, authenticity display body, wherein the <br/> that it contains the wavelength region of specific light diffracted by the diffraction layer. Wherein the reflective portion of the reflection layer, authenticity display body according to claim 1 or 2, characterized in that it is formed so as to overlap only a portion of the diffraction layer. The authenticity display body according to any one of claims 1 to 3 , wherein the cholesteric regularity structure of the reflecting portion is in a planar alignment state. The authenticity display body according to any one of claims 1 to 4 , wherein the reflection layer further includes a transmission portion that transmits incident light. The authenticity display body according to claim 5 , wherein the reflective layer includes a plurality of reflective portions and a plurality of transmissive portions arranged side by side. The authenticity display body according to any one of claims 1 to 6 , wherein only a part of the reflection portion is in a planar alignment state. Than said reflective layer and the diffraction layer is disposed on the back side which is opposite to the observation side, of the claims 1 to 7, further comprising a sticking layer that enables attached to the object The authenticity display body as described in any one of Claims. The authenticity display body according to claim 8 , further comprising a peelable peelable member laminated on the back side of the adhesive layer. The authentic display according to any one of claims 1 to 9 , wherein the diffraction layer is made of a reflection type volume hologram.

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