JP5332325B2 - Hologram sheet - Google Patents

Description

  The present invention relates to a hologram sheet used for authenticity identification that makes it easy to distinguish a genuine one obtained from counterfeiting or falsification based on an unauthorized intention. The present invention also relates to a product obtained by processing such a hologram sheet into a label form or transfer sheet form suitable for application to an article.

  In the present specification, “part” indicating the formulation is based on mass. The “hologram” includes a hologram and a hologram having a light diffractive function such as a diffraction grating.

  (Main use) The main use of the hologram sheet of the present invention is a hologram sheet used in the field of anti-counterfeiting. Specifically, when used as a counterfeit such as a credit card, the card holder That may cause damage to the credit card company, driver's license, employee ID card, membership card, ID card, entrance examination voucher, passport, banknote, gift certificate, point card, stock certificate, securities, lottery ticket There are horse tickets, bankbooks, boarding tickets, pass tickets, air tickets, admission tickets for various events, play tickets, prepaid cards for public transportation and public telephones.

Each of these is an information recording medium holding information having economic or social value, and it is desired to have a function capable of identifying the authenticity of the medium itself for the purpose of preventing damage caused by forgery.

In addition to these information recording media, expensive products such as luxury watches, luxury leather products, precious metal products, jewelry, etc., often referred to as luxury brand products, or storage of such expensive products. Boxes and cases can also be forged. In addition, mass-produced products of famous brands, such as audio products, electrical appliances, etc., or tags that are hung on them are also subject to forgery.

Furthermore, a storage medium on which music software, video software, computer software, game software, or the like, which is a copyrighted work, or cases thereof can also be forged. In addition, it is desirable that products such as printer toner, paper, and the like in which supplies to be replaced are limited to genuine materials have a function of identifying their authenticity for the purpose of preventing damage caused by forgery.

(Background technology)
Conventionally, for the purpose of preventing counterfeiting of information recording media and the above-mentioned various articles (collectively referred to as authenticity identification objects), it is said that they have manufacturing difficulties due to the precision of their structures. In many cases, holograms are applied as authenticity distinguishable. However, since the hologram manufacturing method itself is known and can be precisely processed by that method, when the hologram is merely for visual judgment, there is no difference between a genuine hologram and a forged hologram. It is difficult to distinguish.

  These authentic identification objects, in particular, articles that have been subjected to hologram images in the form of labels or transfer sheets, are subject not only to authentic identification of visual confirmation of hologram images, but also using a new authenticity identification method. There is a need to identify the authenticity of things.

(Prior art)
In order to meet these requirements, an authenticity identification medium is proposed that has a light selective reflection layer that is laminated on a hologram and reflects only one of the left-handed polarized light and the right-handed polarized light in the incident light. It was. (For example, refer to Patent Document 1).

  However, in order to identify the authenticity of the authenticity identification object subjected to the authenticity identification medium, a special determination tool for determining the light selective reflectivity, that is, a “linear polarizer” is provided. It is necessary to prepare a judgment tool in advance, and it will be clearly recognized as an authenticity recognition operation in front of the person who presented the authenticity identification target object, and the person's heartbeat will be significantly impaired. There are disadvantages.

To deal with this problem, even if the authenticity identification work is performed in front of the person who presented the authenticity identification object, the person is not aware that he is doing the work. As a method for implementing the above, it is possible to envisage a method in which a temperature indicating ink whose color tone changes only by touching the authenticity identification object is applied to the hologram. Typical examples of temperature indicating inks use heavy metals, but it is necessary to consider the influence on the human body. It has been proposed to use a certain temperature-sensitive liquid crystal. (For example, refer to Patent Document 2).

However, the proposed application is a kind of thermometer for visualizing the temperature of the contents. Combined with the number for displaying the temperature, the change in color tone and the number are compared with the temperature of the contents. It is a guess. That is, the presence of the liquid crystal itself is explicitly used, and the presence of the liquid crystal is concealed and is not assumed to be used for authenticity identification such as secretly used for determination.

JP 2005-301093 A JP-A-10-213493

  Accordingly, the present invention has been made to solve such problems. The purpose is to identify the authenticity of the hologram provided in the authenticity identification object without the need for a special judgment tool and without being realized by the person who presented the identification object. It is possible to provide an authenticity identification medium capable of

In order to solve the above problems, state-like hologram sheet of the present invention is a hologram forming layer formed with a hologram relief on one surface of a transparent substrate, reflective on its part in contact with the hologram relief thin film is partially formed, on the front Symbol reflective film, which is a feature and the hologram sheet that temperature-sensitive liquid crystal is formed in accordance with the shape of the reflective film is partially formed.

Further, in the temperature sensitive liquid crystal formation side of the hologram sheet may I further adhesive is formed optionally sulfo program labels der.
Further, in the temperature sensitive liquid crystal formation side of the hologram sheet may I further adhesive is formed sulfo program transfer sheet der.

According to the hologram sheet of above Kitai like, the hologram sheet is provided on the authenticity of the identification object, the identification object, for example, as a credit card, the card wearer, its authenticity Is presented to the person who confirms (hereinafter referred to as the judge). At this time, the determiner receives the identification object, visually confirms the hologram and determines that it is authentic, but immediately thereafter, presses the hologram with a finger and heats only a part of the hologram with body temperature.

By this operation, the temperature-sensitive liquid crystal provided under the hologram changes its color tone, so that the hologram is determined to be authentic. Thereafter, for example, in the case of a credit card, the determiner performs a confirmation operation such as inquiring a credit company for magnetic data recorded on the card, and returns the card to the card carrier after confirmation. At this time, the color tone of the temperature-sensitive liquid crystal must already be restored. This series of work takes several tens of seconds.

When the judge removes his / her finger from the card, the temperature of the temperature-sensitive liquid crystal begins to drop, but the temperature difference between room temperature and body temperature is small (about 10-15 ° C), and it takes time for the temperature to drop due to natural cooling. Cheap. However, since an operation that is not normally performed, such as cooling the card, cannot be performed during the determination operation, the temperature that drops in tens of seconds is only a few degrees.

For this reason, a temperature-sensitive liquid crystal is used in which the color tone is quickly changed by a slight temperature change in the vicinity of the set temperature, and the shake with respect to the set temperature (temperature to be changed) is hardly observed. By returning to the original color tone with a temperature drop of several degrees Celsius for a short time, the authenticity of the hologram can be determined without being noticed by the identification subject presenter, for example, the cardholder.

Moreover, a hologram can be stuck on an authenticity identification target object by forming an adhesive in a hologram sheet. Further, by forming an adhesive on the hologram sheet to obtain a hologram transfer sheet, the hologram can be transferred onto the authenticity identification object.

After transferring this transfer sheet onto the identification object, the transparent base material is peeled off, so that only the layer below the hologram forming layer can be left on the identification object. The distance to the liquid crystal can be reduced to about several μm. That is, heating and cooling can be performed instantaneously, and the determination operation can be performed in a shorter time.

After confirming this color tone change, the hologram sheet naturally cools as soon as the finger is released, but the cooling rate is slow, and it takes several seconds or more to drop once. However, the cholesteric liquid crystal having a set temperature of 28 ° C. and the chiral nematic liquid crystal sufficiently react to this slight temperature change, and the color tone is already restored at 27 ° C. After this confirmation, the judge performs identity verification work such as magnetic data verification of the card holder, and then returns the card to the card holder.

In other words, a hologram sheet is provided in which the color tone is changed by heating with a finger, and at the same time the finger is released, the original color tone is quickly restored, and the determination operation can be made without the authenticity identification object carrier noticing the determination operation. It will be .

According to the hologram sheet of the present invention, the hologram provided on the authenticity identification object is authentic, without requiring special determination instrument, and, be convince the person who presents the identification object In addition, there is an effect that an authenticity identification medium capable of authenticity identification is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of a hologram sheet A showing an example of an embodiment of the present invention.
FIG. 2 is a sectional view of a hologram label A ′ showing another example of the embodiment of the present invention.
FIG. 3 is a cross-sectional view of a hologram transfer sheet A ″ showing still another example of the embodiment of the present invention.

  (Transparent substrate) The transparent substrate 1 used in the hologram sheet or the like of the present invention can be thinned, and has a mechanical strength and a hologram sheet A, hologram label which is a medium for authenticity determination. It is preferable to have a solvent resistance and a heat resistance that can withstand the processing when manufacturing A ′ and the hologram transfer sheet A ″. Since it depends on the purpose of use, it is not limited, but a film-like or sheet-like plastic is preferable.

For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, and polyethylene / vinyl alcohol can be exemplified. .

When the body temperature of the human body is quickly transmitted to the temperature-sensitive liquid crystal when it is pressed with a finger for authenticity judgment, etc., the color change (including light scattering) is confirmed, and after the change is confirmed, the temperature-sensitive liquid crystal is cooled. Since it is necessary to quickly release heat, the transparent base material preferably has high thermal conductivity. From the same consideration, the thickness of the transparent substrate is desirably 5 to 50 μm, particularly 5 to 15 μm.

However, when the transparent substrate is the substrate of the transfer sheet, the transparent substrate peels off after transferring the hologram onto the authenticity identification medium and does not remain on the authenticity identification medium. There is no need to limit thermal conductivity or thickness. After hologram transfer, heat is transferred to the temperature-sensitive liquid crystal only through the hologram forming layer, so that the determination can be performed with higher accuracy.
Moreover, when forming a transfer sheet, you may provide the peeling layer which consists of a cellulose acetate resin, a methacryl resin, etc. which are used normally in the transparent base material 1. FIG.

  (Hologram Forming Layer) As the transparent resin material for constituting the hologram forming layer 2 of the present invention, various thermoplastic resins, thermosetting resins, or ionizing radiation curable resins can be used. Thermoplastic resins include acrylic ester resins, acrylamide resins, nitrocellulose resins, or polystyrene resins. Thermosetting resins include unsaturated polyester resins, acrylic urethane resins, epoxy-modified acrylic resins, and epoxy-modified unsaturated resins. A polyester resin, an alkyd resin, a phenol resin, etc. are mentioned.

These thermoplastic resins and thermosetting resins can be used alone or in combination of two or more. One or more of these resins may be cross-linked using various isocyanate resins, or various curing catalysts, for example, metal soap such as cobalt naphthenate or zinc naphthenate may be blended. Or peroxide such as benzoyl peroxide and methyl ethyl ketone peroxide for initiating polymerization with heat or ultraviolet light, benzophenone, acetophenone, anthraquinone, naphthoquinone, azobisisobutyronitrile, or diphenyl sulfide good.

Examples of the ionizing radiation curable resin include epoxy acrylate, urethane acrylate, acrylic-modified polyester, etc., for the purpose of introducing a crosslinked structure into such an ionizing radiation curable resin or adjusting the viscosity, A monofunctional monomer, a polyfunctional monomer, or an oligomer may be blended and used.

In order to form the hologram forming layer 2 using the above resin material, it can be directly formed by developing the photosensitive resin material by performing interference exposure of the hologram. It is preferable to perform molding by using a replica or a plating mold thereof as a replica mold and pressing the mold surface against the layer of the resin material.

When thermosetting resin or ionizing radiation curable resin is used, curing is performed by heating or ionizing radiation irradiation while keeping the uncured resin in close contact with the mold surface, and then cured by peeling after curing. The fine irregularities of the relief hologram can be formed on one side of the layer made of a transparent resin material. A diffraction grating forming layer having a diffraction grating formed in a pattern by a similar method can also be used as the optical diffraction structure.

  A hologram is a recording of interference fringes due to interference of light between object light and reference light in an uneven relief shape. For example, a laser reproduction hologram such as a Fresnel hologram, a white light reproduction hologram such as a rainbow hologram, There are color holograms utilizing the above principle, computer generated holograms (CGH), holographic diffraction gratings and the like. Further, like a machine readable hologram, the reproduction light may be converted into data by a light receiving unit and transmitted as predetermined information, or authenticity determination may be performed.

In order to precisely create fine irregularities, not only optical methods, but also electron beam lithography equipment can be used to create precisely designed relief structures that produce more precise and complex reproduction light. Good. The relief shape is designed to have a pitch, depth, or specific periodic shape of the unevenness according to the wavelength (range) of the light or light source for reproducing or reproducing the hologram, the direction and the intensity of reproduction or reproduction. The pitch (period) of the unevenness depends on the reproduction or reproduction angle, but is usually 0.1 μm to several μm, and the depth of the unevenness is a factor that greatly affects the reproduction or reproduction intensity, but is usually 0.1 μm. ˜1 μm.

As in the case of a single diffraction grating, when the unevenness of exactly the same shape is repeated, as the adjacent unevenness is the same shape, the degree of interference of reflected light increases and the intensity increases, and the maximum value is reached. Converge. Diffraction in the diffraction direction is also minimized. When a single point of an image converges to a focal point, such as a stereoscopic image, the convergence accuracy to the focal point is improved, and a reproduced or reproduced image becomes clear.
Further, in the case of a transparent metal compound thin film, the upper and lower surfaces of the thin film have the same relief shape, and the more uniform the distance between the surfaces (that is, the film thickness), the higher the reproduction or reproduction strength. growing. In addition, if there are irregularities having a period and shape different from the irregularities of the hologram image on the relief surface, this becomes noise during reproduction or reproduction of the hologram or diffraction grating, which causes the image to become unclear.

  The method of shaping (also called replicating) the relief shape is to use an original plate on which diffraction gratings and interference fringes are recorded in a concavo-convex shape as a press die (referred to as a stamper) on the transparent substrate 1 and the reflective thin film 2. The concavo-convex pattern of the original plate can be duplicated by stacking the original plate and heat-pressing both of them with an appropriate means such as a heating roll. The hologram pattern to be formed may be single or plural.

In order to accurately reproduce the above-mentioned extremely fine shape and to minimize distortion and deformation such as heat shrinkage after replication, the original plate is made of metal and replicated at low temperature and high pressure.
For the original plate, a metal having high hardness such as Ni is used. After a Cr or Ni thin film is formed on the surface of a glass master or the like formed by optical photography or electron beam drawing by vacuum deposition or sputtering, Ni or the like is electrodeposited (electroplating, electroless plating, Furthermore, after forming 50-1000 micrometers by composite plating etc., it can make by peeling a metal.

The duplication method uses a flat plate type or a rotary type, the linear pressure is 0.1 ton / m to 10 ton / m, and the duplication temperature is usually 60 ° C to 200 ° C.

(Reflective thin film) In the hologram sheet or the like of the present invention, the reflective thin film layer 3 is partially or entirely formed on the hologram relief surface of the hologram forming layer. Since this thin film needs to reflect incident light, it is not particularly limited as long as it has a higher refractive index than that of the hologram forming layer 2.
The reflective thin film may be either a metallic gloss reflective layer such as a metal thin film formed by a vacuum thin film method or a transparent reflective layer, but a metallic gloss reflective layer is provided partially or a transparent reflective layer is provided. In this case, it is preferable because the change of the temperature-sensitive liquid crystal provided in contact with the reflective layer can be confirmed through the transparent reflective layer.

As a transparent reflective layer, it is almost colorless and transparent, and its optical refractive index is different from that of the hologram forming layer. A simple hologram can be produced. For example, a thin film having a higher refractive index than a hologram forming layer (in the present invention, which corresponds to a transparent biodegradable plastic film or sheet 1), for example, ZnS, TiO ₂ , Al ₂ O ₃ , Sb ₂ There are S ₃ , SiO, SnO ₂ , ITO and the like.

Preferably, it is a metal oxide or nitride, specifically, Be, Mg, Ca, Cr, Mn, Cu, Ag, Al, Sn, In, Te, Ti, Fe, Co, Zn, Ge, Pb. Cd, Bi, Se, Ga, Rb, Sb, Pb, Ni, Sr, Ba, La, Ce, Au, and other oxides or nitrides, and the like can be exemplified by a mixture of two or more thereof. Also, a general light-reflective metal thin film such as aluminum can be used as a transparent reflective layer when it has a thickness of 20 nm or less and becomes transparent.

  The transparent metal compound is formed on the hologram relief surface of the hologram forming layer 2 by vapor deposition, sputtering, ion plating, CVD (to the thickness of about 10 to 2000 nm, preferably 20 to 1000 nm, similarly to the metal thin film. It may be provided by a vacuum thin film method such as a chemical vapor deposition method.

  (Temperature-sensitive liquid crystal) The temperature-sensitive liquid crystal 4 used in the present invention changes from solid phase to liquid crystal phase to liquid phase depending on the temperature. Has the same strong anisotropy as a solid crystal and maintains the orientational order of the molecule in the same way as the solid crystal even though the crystal lattice order of the rod-like molecule is lost and becomes liquid under a certain temperature condition. Any thermotropic liquid crystal in which this phenomenon appears before the melting point can be used.

This liquid crystal is classified into a smectic liquid crystal, a nematic liquid crystal, and a cholesteric liquid crystal depending on the characteristics of the molecular arrangement. Each of these liquid crystals is used alone, but may be used in combination. Furthermore, polymer-based thermotropic liquid crystals are also used. Representative examples include a p-azoxyanisole skeleton, an N- (p-methoxybenzylidene) -p-busyaniline skeleton, and a 4-cyano-4'-benzylbiphenyl skeleton, and the liquid crystal expression temperature is adjusted by the side chain length. However, some have optical activity by introducing asymmetric molecules. In any case, the molecular arrangement forms a layer structure, causing a change in refractive index. The color tone changes as the layer spacing of each layer of this layer structure changes with temperature.

In the polymer system, a polyester main chain type having an aromatic ring unit as a mesogen, a polyester main chain type having a methylene chain mixed unit, a polyester main chain type having an optically active diol or dicarboxylic acid mixed unit, polyimide, polycarba Examples thereof include a polymer blend in which a liquid crystal polymer is blended with a thermoplastic resin in addition to a thermotropic polymer of a main chain type such as a narate, a polyether, a polyurethane, and a polyamide. Of course, a hydrated gel comprising polyoxypropylene 2-ether-2-hydroxymethyl-1,1,3-propanidol in hydroxypropyl cellulose and water can also be used, and various polymer-dispersed liquid crystals can also be used. .

Cholesteric liquid crystals include cholesterol halides, monocarboxylic acid cholesterol esters, monocarboxylic acid sitosterol esters, benzoic acid derivative cholestanol esters, dibasic acid dicholesteryl esters, main chain liquid crystal polymer compounds, side chain liquid crystal polymers Examples thereof include molecular compounds and rigid main chain type liquid crystal polymer compounds.

More specifically, for example, cholesteryl chloride, cholesteryl acetate, cholesteryl nonanoate, methyl carbonate, ethyl cholesterol, cholesteryl p-methoxybenzoate, sitosteroyl benzoate, sitosteroyl p-methyl benzoate, cholestanyl benzoate, 10, 12- Docosadiin dicarboxylic acid dicholesteryl ester, 8,12-eicosadicarboxylic acid dicholesteryl ester, 10,12-pentacosadiin dicarboxylic acid dicholesteryl ester, dodecadicarboxylic acid dicholesteryl ester, 12,14-hexacosadiin dicarboxylic acid Dicholesteryl ester, 4- (7-cholesteryloxycarbonylheptyloxy) phenoxyoctanoic acid cholesteryl ester, L-glu Min acid -γ- benzyl / L-glutamate -γ- dodecyl copolymers and the like.

Further, cholesteryl formate, cholesteryl acetate, cholesteryl propionate, cholesteryl butyrate, cholesteryl pentanate, cholesteryl hexanate, cholesteryl heptanoate, cholesteryl octanate, cholesteryl nonanoate, cholesteryl decanate, cholesteryl decanate (cholesteryl laurate) Cholesteryl myristate, cholesteryl palmitate, cholesteryl stearate, cholesteryl oleate, cholesteryl oleyl carbonate, cholesteryl linoleate, cholesteryl 12-hydroxystearate, cholesteryl mercaptan, cholesterol chloride, cholesteryl fluoride, cholesteryl bromide, cholesteryl iodide, etc. Can be mentioned.

Preferably, a mixture of three kinds of alkyl cholesterol (for example, cholesterol nanoate) and cholesteryl halide (for example, cholesterol chloride) cholesteryl oleyl carbonate is used, and these three types of liquid crystals are used so as to be used at room temperature. Is common.

In addition, it is not limited to the compound shown here, Moreover, these cholesteric liquid crystal compounds can be used 1 type or in mixture of 2 or more types. Furthermore, other liquid crystalline compounds such as nematic liquid crystals and smectic liquid crystals having no chiral component may be added to these cholesteric liquid crystal compounds.

As the chiral nematic liquid crystal, as a liquid crystal compound, 4-substituted benzoic acid 4′-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4′-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4′-substituted biphenyl ester, 4- (4-Substituted cyclohexanecarbonyloxy) benzoic acid 4′-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4′-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4′-substituted cyclohexyl ester 4-substituted 4′-substituted biphenyl, 4-substituted phenyl 4′-substituted cyclohexane, 4′-substituted cyclohexane, 2- (4-substituted phenyl) -5-substituted pyridine and the like are used.

Particularly preferably, a liquid crystal compound having a cyano group or a fluorine atom at least at one end of the molecule is used, and various suitable chiral agents are added to these liquid crystal compounds. As the chiral compound, “CB-15”, “C-15” (manufactured by BDH), “CM-21”, “CM-22”, “CM-19”, “CM-20”, “CM” (Above, manufactured by Chisso Corporation), "S1082", "S-811", "R-811" (above, manufactured by Merck & Co., Inc.) and the like.

Further, a cholesteric liquid crystal having no cholesterol group in which a group having an asymmetric carbon is introduced into a terminal group of a nematic liquid crystal obtained by organic synthesis, or a mixed liquid crystal in which a Schiff nematic liquid crystal is added to a cholesterol derivative is also used. Furthermore, halogen substitution products and esterified products of natural cholesterol (cholesteryl benzoate, cholesteryl chloride, cholesteryl oleate, cholesteryl nonanoate, and the like are also suitable.

Among these temperature-sensitive liquid crystals, those that react with the body temperature of the human body (about 36 ° C.) and cause changes in color tone (including light scattering) are particularly suitable. Those that vary are preferred. The changing accuracy is preferably ± 3 ° C., more preferably ± 0.5 ° C. Further, it is preferable that the rate of change changes instantaneously (about several seconds) when the change temperature is reached, and returns instantly when the temperature falls below the change temperature.

As a method for providing these temperature-sensitive liquid crystals, a solvent-based, water-based, or solvent-free system can be formed using a normal coating method. However, an ink in which the temperature-sensitive liquid crystal is encapsulated with gelatin or other resin film is used. May be used. The encapsulated product not only has excellent workability during production, but also has excellent physical properties (toughness, wear resistance, heat resistance, etc.) and prevents defects such as liquid crystal seepage. It is particularly suitable in terms of hygiene.

The thickness to be formed is a thickness that causes sufficient color change (including light scattering) to perform authenticity determination, but it is desirable that the thickness is thin in order to conceal the presence of the temperature-sensitive liquid crystal. . That is, 5 to 50 μm, preferably 5 to 20 μm. In order to further improve confidentiality, partial formation of thermosensitive liquid crystal, partial formation of hologram relief or reflective thin film layer, and formation of thermosensitive liquid crystal according to the shape of the partially formed reflective thin film It is also possible to form a temperature-sensitive liquid crystal smaller than the portion. Further, when the temperature-sensitive liquid crystal is partially formed, it is also preferable to fill the blank portion with another resin so that the step and the color tone difference are not noticeable.

When the reflective thin film is a metal, it is desirable to take the means of confirming the color tone change of the contour portion of the reflective thin film when it is warmed with a finger or palm in the same shape as the reflective thin film. Furthermore, in order to make it easier to determine the authenticity, it may be possible to devise a specific character or symbol shape or synchronize with the hologram design.

When the temperature-sensitive liquid crystal is provided, an alignment treatment such as providing the following alignment film may be performed in advance. Any alignment film may be used as long as it can be generally used as an alignment film, such as polyvinyl alcohol resin (PVA) or polyimide resin. For the alignment film, a solvent solution of these resins is applied to the surface of the reflective thin film layer 3 as described above by an appropriate application method, dried, and then rubbed with a cloth, a brush, or the like. Form.

  (Adhesive) As the adhesive 5 used in the hologram label of the present invention, any conventionally known solvent-based or water-based adhesive, for example, vinyl acetate resin, acrylic resin, vinyl acetate-acrylic copolymer, vinyl acetate. -Vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyurethane resin, and rubber-based resins such as natural rubber and chloroprene rubber. Natural latex such as natural rubber latex, natural rubber latex obtained by graft polymerization of natural rubber with styrene, especially methacrylic acid methyl, in particular, to make natural material composition You may use what was produced from the raw material.

The coating amount of the pressure-sensitive adhesive 5 is generally about 8 to 30 g / m ² (solid content), and is applied and dried by a conventionally known method, that is, a gravure coat, roll coat, comma coat or the like. To form an adhesive layer. The adhesive strength of the pressure-sensitive adhesive is the peel strength between the temperature-sensitive liquid crystal 4 and the pressure-sensitive adhesive 5, and is preferably in the range of about 500 to 1,000 g in the 180 ° peeling method in accordance with JIS Z0237. It is preferable to select and use the type of adhesive and the coating amount as described above so that when the adhesive 5 is formed on the temperature-sensitive liquid crystal 4, the peel strength is within the above range.
In particular, in order to make the adhesion to the temperature-sensitive liquid crystal 4 5,000 g to 1,000 g, 0.1% to 1% of polyfunctional isocyanate: HMDI (hexamethylene diisocyanate) or the like is added to stabilize the adhesive force. There is also a method for obtaining high adhesion and high adhesion to the temperature-sensitive liquid crystal 4.

  (Adhesive) Since the adhesive 5 used in the hologram transfer sheet of the present invention is for ensuring the adhesiveness to various articles, the adhesive with the temperature-sensitive liquid crystal 4 is good, and the adherend and What can adhere | attach firmly is preferable. Specific examples include vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, acrylic resins, polyester resins, polyurethane resins, polyamide resins, and rubber-modified products. Appropriately selected from the above can be used, and these can be used alone or in a mixture of two or more, and if necessary, hard resin, plasticizer, and other additives can be added and used. it can.

The coating amount of the adhesive 5 is generally about 3 to 10 g / m ² (solid content), and is applied and dried by a conventionally known method, that is, a gravure coat, roll coat, comma coat or the like. To form an adhesive layer. Further, the adhesive strength of the adhesive is the peel strength between the temperature-sensitive liquid crystal 4 and the adhesive 5 or the adhesive 5 and the article, and is in the range of about 500 to 1,000 g in a 180 ° peeling method in accordance with JIS Z0237. It is desirable to do. It is preferable to select and use the adhesive type and the coating amount as described above so that the peel strength is within the above range when the adhesive 5 is formed on the temperature-sensitive liquid crystal 4.
In particular, in order to adjust the adhesiveness to the temperature-sensitive liquid crystal 4 to 5,000 g to 1,000 g, 0.1% to 1% of polyfunctional isocyanate: HMDI (hexamethylene diisocyanate) or the like is added, and the back adhesive strength is increased. There is also a method for obtaining stability and high adhesion to the temperature-sensitive liquid crystal 4.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this.

Example 1
A transparent ultraviolet curable resin composition is applied to the surface of a PET film having a thickness of 12 μm, and 3 μm is applied to the surface of the relief hologram duplication mold. A relief hologram is formed by curing, and then ZnS is vacuum-deposited on the surface of the relief hologram formed to form a transparent reflective layer having a thickness of 200 nm. Apply a temperature-sensitive liquid crystal ink (Nihon Capsule Products RW-ELC red: color development temperature 30 ° C.) containing liquid crystal in an encapsulation of about 20 μm, and after drying, the thickness is 20 μm to obtain hologram sheet A It was.

After this hologram sheet was left in a room at room temperature of 20 ° C., when the thumb was pressed firmly against the surface of the transparent substrate for 5 seconds, the temperature-sensitive liquid crystal that was red under the hologram image became a finger shape. Green. After confirming this color tone, when it was allowed to stand at room temperature for 10 seconds, the green color quickly changed and returned to the original red color. As a result, the state is the same as before the determination operation was performed, and the determination operation was only held with a finger for 5 seconds. Therefore, it was assumed that the third party would not notice that these determination operations were performed.

(Example 2)
On the temperature-sensitive liquid crystal of the hologram sheet of Example 1, the following composition was applied with a gravure coater so that the coating amount after drying was 20 μm and dried at 70 ° C. to form an adhesive 5. A hologram label A ′ of Example 2 was obtained.
・ <Adhesive composition>
Vinyl acetate-acrylic copolymer 30 parts by mass Toluene 40 parts by mass Vinyl acetate 40 parts by mass

This hologram label was cut out to a diameter of 8 mm according to the hologram image, stuck on the name of the credit card on which the card company name was printed, and left at room temperature of 20 ° C. Thereafter, when the thumb was strongly pressed against the transparent substrate surface for 5 seconds, the temperature-sensitive liquid crystal that was red under the hologram image was entirely green. After confirming this color tone, when it was allowed to stand at room temperature for 10 seconds, the green color quickly changed and returned to the original red color.

As a result, the same state as before the determination operation is performed, and the determination operation is also an operation for handling the card, and the third party confirms that these determination operations have been performed because only the finger on the hologram label is pressed for 5 seconds. I guess it was not noticed.

(Example 3)
A transparent ultraviolet curable resin composition is applied to the surface of a PET film having a thickness of 25 μm, and 3 μm is applied to the surface of the relief hologram replication mold, and then irradiated with ultraviolet rays to bring the transparent ultraviolet curable resin composition into contact. The relief hologram is formed by curing, and then AL is vacuum-deposited on the surface of the relief hologram to form a reflective metal layer having a thickness of 100 nm, on which cholesteric liquid crystal is formed. A temperature-sensitive liquid crystal ink (Nippon Capsule Products RW-ELC red: color development temperature 30 ° C.) included in the encapsulation having a size of about 20 μm was applied, and after drying, the thickness was 20 μm to obtain a hologram sheet.

On the temperature-sensitive liquid crystal of this hologram sheet, the following composition was applied with a gravure coater so that the coating amount after drying was 5 μm and dried at 70 ° C. to form an adhesive 5. 3 hologram transfer sheet A ″ was obtained.
・ <Adhesive composition>
Vinyl chloride-vinyl acetate copolymer 30 parts by mass Toluene 40 parts by mass Vinyl acetate 40 parts by mass

This hologram label is cut to a diameter of 8 mm in accordance with the hologram image, placed on the name of the credit card on which the card company name is printed, pressed at 150 ° C. for 10 minutes and transferred to the card substrate, and then transparent The substrate was peeled off. As a result, the temperature-sensitive liquid crystal was embedded 3 μm below the outermost surface of the card, and it was confirmed from the card surface that the hologram design and its outline were slightly red.

The card was left at room temperature of 20 ° C., and then the thumb was strongly pressed against the hologram surface for 3 seconds. As a result, the temperature-sensitive liquid crystal that was red in the outline of the hologram image was green. After confirming this color tone, when it was allowed to stand at room temperature for 10 seconds, the green color quickly changed and returned to the original red color.

As a result, the same state as before the determination operation is performed, and the determination operation is also an operation for handling the card, and the third party notices that these determination operations have been performed because the hologram is simply pressed for 3 seconds with a finger. I guess it wasn't. The temperature-sensitive liquid crystal was hidden under the hologram, and it was assumed that even its presence was not noticed.

Example 4
A transparent ultraviolet curable resin composition is applied to the surface of a PET film having a thickness of 12 μm, and 3 μm is applied to the surface of the relief hologram duplication mold. The relief hologram is formed by curing, and then ZnS is vacuum-deposited on the surface of the relief hologram to form a transparent reflective layer having a thickness of 200 nm. Apply a temperature-sensitive liquid crystal ink (Nippon Capsule Products KX-ELC red: color development temperature 35 ° C.) containing nematic liquid crystal in an encapsulation of about 20 μm, and after drying, make the thickness 20 μm. Obtained.

After this hologram sheet was left in a room at a room temperature of 20 ° C., when the thumb was pressed firmly against the surface of the transparent substrate for 10 seconds, the temperature-sensitive liquid crystal that was red under the hologram image became a finger shape. Green. After confirming this color tone, when it was allowed to stand at room temperature for 3 seconds, the green color quickly changed and returned to the original red color. As a result, the state immediately before the execution of the determination operation was promptly assumed, and it was assumed that the third party would not notice that these determination operations were performed.

(Comparative Example 1)
A hologram sheet of Comparative Example 1 was obtained in the same manner as in Example 1, except that TCP63-31 (orange thermochromic pigment 33 ° C. → 35 ° C. decolored) manufactured by HWSANDS was used instead of the temperature-sensitive liquid crystal. .
After this hologram sheet was left in a room at room temperature of 20 ° C., when the thumb was pressed firmly against the surface of the transparent substrate for 5 seconds, the temperature-sensitive liquid crystal that was orange under the hologram image was shaped like a finger. A slightly pale orange color. After confirming the color tone, the color tone did not change much when it was left at room temperature for 10 seconds.

As a result, the determination itself could not be performed. Therefore, it was inferred that it is difficult to perform a determination operation without being noticed by a third party.

It is sectional drawing of the hologram sheet which shows one example of embodiment of this invention. It is sectional drawing of the hologram sheet which shows another example of embodiment of this invention. It is sectional drawing of the hologram sheet which shows another example of embodiment of this invention.

Explanation of symbols

A hologram sheet A ′ hologram label A ″ hologram transfer sheet 1 transparent substrate 2 hologram forming layer 3 reflective thin film layer 4 temperature sensitive liquid crystal 5 adhesive or adhesive

Claims (1)

A hologram sheet for use in authenticity identification, is formed hologram forming layer having a hologram relief on one surface of a transparent substrate, a reflective film is partially formed on the part in contact with the hologram relief, before A hologram sheet characterized in that a thermosensitive liquid crystal is partially formed on the reflective thin film in accordance with the shape of the partially formed reflective thin film .

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