JP4483246B2 - Partially diffractive structure transfer sheet and manufacturing method thereof - Google Patents

Description

  The present invention includes measures for preventing fraud such as counterfeiting, falsification, or theft of information that should be kept secret, and measures for facilitating the determination of fraud even if such fraud is concerned. [In this specification, these measures are collectively referred to as anti-counterfeiting measures].

  More specifically, for example, counterfeiting measures to prevent counterfeiting of securities such as gift certificates and credit cards, and counterfeiting to prove that they are genuine products that are often applied to generally expensive items such as branded products and luxury products. Anti-counterfeiting transfer sheet which is a technology suitable for these needs, a technology capable of obtaining a visual effect excellent in decorativeness depending on the design, and which can obtain a higher effect in combination with OVD, and It relates to the manufacturing method.

  In recent years, as an example of a technique for developing an optical effect, there are conventional holograms and diffraction gratings that can express stereoscopic images, special decorative images, or special color changes using light interference, and optical characteristics. So-called OVD using a technique such as a multilayer thin film that causes a color change (color shift) depending on the viewing angle by superimposing thin films having different optical layers on an optically appropriate multilayer is used. [OVD is an abbreviation for “Optical (ly) Variable Device”. Note that DOVID is also a synonym for OVD, and is an abbreviation for “Differential Optical (ly) Variable Imaging Device”. ].

  Regarding the change in color, there is a phenomenon in which the color is changed due to the material and structure of the OVD, and the color itself is changed depending on the wavelength of light. In the present specification, such a color is referred to as a structural color. Examples of optical phenomena related to the expression of structural colors include multilayer film interference, thin film interference, refraction, dispersion, light scattering, Mie scattering, diffraction, and diffraction grating.

  This OVD requires advanced manufacturing technology, has a unique visual effect, and can determine authenticity at a glance, so it can be formed on a part or all of credit cards, securities, certificates, etc. as an effective counterfeiting measure. Is being used. Recently, in addition to securities, it is affixed to sports equipment, computer parts and other electrical product software, etc., as an authentication sticker that proves the authenticity of the product, and as a seal sticker that is affixed to the package of those products Has also become widely used.

  As described above, OVD is generally an anti-counterfeiting means that is difficult to elaborate and easy to check, but there are many thermal transfer methods that are not easy to replace when attached to paper media such as gift certificates, banknotes, passports, or stock certificates. The case has been adopted. As described above, conventionally, when a transfer sheet such as a hologram is used to form on a transfer material, there is a problem that the metal vapor deposition layer is cracked or whitened due to heat or pressure during transfer.

  In order to solve this problem, a hologram transfer sheet that exhibits an excellent effect on heat during transfer has been proposed [for example, Patent Document 1]. According to this, a distortion (white turbidity or crack) of the hologram image is prevented by providing a heat-resistant protective layer formed of a thermosetting resin on the metal vapor deposition layer between the adhesive layer.

Japanese Patent Publication No. 7-92635 (2nd page)

  However, in the above case, it is certainly an effective means for preventing thermal whitening during transfer, but heat resistance after transfer (after peeling of the heat-resistant film substrate) is not considered. When attached to conventional cards (in many cases, vinyl chloride cards), the heat resistance of the transfer material (card) (glass transition temperature: around 70 ° C) is not sufficient, so the heat resistance after attachment Was unnecessary. In recent years, attachment to paper media has changed from the mainstream, and when gift certificates and banknotes are taken as examples, laundering may occur without being noticed in a wallet or pocket. In this case, it is assumed that many users attempt ironing and reproduction.

  The surface temperature of the iron is 150 ° C. to 250 ° C. (average 200 ° C.) at a high temperature setting, and even if heat loss due to evaporation of moisture is taken into consideration, the temperature reaching the metal vapor deposition layer of the hologram is 150 It can be estimated to be about ℃.

  In the case of the thermosetting acrylic resin and thermosetting urethane resin in the conventional example [Patent Document 1], the glass transition temperature is about −20 ° C. to 105 ° C. (before curing), and the glass transition temperature after curing is At most, 120 to 130 ° C. is the practical limit. It is possible to obtain a cured film with a glass transition temperature of around 140 ° C by using a material with a high degree of curing (high reactivity) or by performing high-temperature and long-time treatment. ) And the deformation of the film base material, the deposited layer and the fine relief pattern are distorted in the reverse direction, which greatly deviates from the fundamental purpose. Moreover, although thermosetting resin is implement | achieved by using a hardening | curing agent together, the functional group for providing adhesiveness with another layer (for example, a metal vapor deposition layer or an adhesive layer) is with a hardening | curing agent. Troubles such as loss due to the reaction process and subsequent delamination have also occurred.

  In this way, even if it is careless by the user, the OVD medium attached for the purpose of preventing forgery may be deformed by an action that may occur in daily life, or, in extreme cases, destruction. -It is not desirable to disappear. Counterfeiting of securities is regarded as a fine criminal act, and it is an issue that must be avoided for good users.

  The present invention has been proposed in view of the above-described problems of the conventional technology, and when the heat resistance after transfer (approx. 150 to 250 ° C. (200 ° C. on average) is applied) However, the transfer layer has a level that does not hinder the generation of diffracted light, does not cause wrinkles or cloudiness, and the transfer layer can partially express diffracted light. It is an object of the present invention to provide a partially diffractive structure transfer sheet that satisfies the above requirements, and to provide a design that gives a transferred appearance that is rich in design to the transferred object.

The present invention solves such a problem, and the present invention according to claim 1 is a partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light, which has heat resistance. A transparent diffractive structure having at least a heat-resistant protective layer that can be peeled from the support, and a minute uneven surface for generating diffracted light, on a sheet-like support having a surface from the side close to the support Forming layer, diffraction effect layer in which a thin film is partially provided on the concavo-convex surface, a heat-resistant mask layer provided so as to cover at least a region having the diffraction effect layer, and a surface of the heat-resistant mask layer and the heat-resistant mask An adhesive layer provided so as to cover the surface of the diffractive structure forming layer without the layer, and the material of the heat-resistant mask layer is a thermoplastic resin having a glass transition temperature of 150 ° C. or higher, a specific gravity of 1 containing 60% or more at a ratio of when converted It is intended to provide a partial diffractive structure transfer sheet according to claim.

The present invention according to claim 2 is a partial diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light, on the sheet-like support having heat resistance, the support A heat-resistant protective layer that can be peeled from the support at least from the side close to the body, a transparent diffractive structure forming layer partially having a minute uneven surface for generating diffracted light, and a thin film on the uneven surface The provided diffraction effect layer, at least the heat-resistant mask layer provided so as to cover the region having the diffraction effect layer, and the surface of the heat-resistant mask layer and the surface of the diffraction structure forming layer without the heat-resistant mask layer The material of the heat-resistant mask layer comprises 60% or more of a thermoplastic resin having a glass transition temperature of 150 ° C. or more in a ratio when the specific gravity is converted to 1. Characteristic partial diffraction structure transfer sheet It is intended to provide.

  According to a third aspect of the present invention, the material of the heat-resistant mask layer has resistance to acid or alkali, and is provided on the diffraction effect layer, and is substantially above the diffraction structure forming layer. The partial diffractive structure transfer sheet according to claim 1, wherein the partial diffractive structure transfer sheet is provided.

The present invention according to claim 4 provides the partially diffractive structure transfer sheet according to any one of claims 1 to 3 , wherein the thin film is a reflective film that reflects light. is there.

The present invention according to claim 5, wherein the thin film is, the diffractive structure formed layer refractive index higher than that, claims 1 to 3 noise insertion to be transparent film having light transparency, the said A partially diffractive structure transfer sheet as described above is provided.

The present invention according to claim 6 has at least two types as the thin film, one is a reflective film that reflects light, and the other has a refractive index higher than that of the diffraction structure forming layer and has light transmittance. The transparent film has a region where the reflective film is present and the region where the transparent film is present are at least regions different from each other, or at least the region where only the transparent film is present and the reflective layer The partial diffractive structure transfer sheet according to any one of claims 1 to 3 , characterized in that there is a relationship between a film and a region where the transparent film overlaps. Is.

The present invention according to claim 7 is a method of manufacturing a partial diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light, on a sheet-like support having heat resistance Further, from the side close to the support, at least a heat-resistant protective layer that can be peeled off from the support, a transparent diffractive structure-forming layer having a minute uneven surface for generating diffracted light, and a thin film on the uneven surface Is partially provided in a diffraction effect layer, a thermoplastic resin having a glass transition temperature of 150 ° C. or higher so as to cover at least a region having the diffraction effect layer, and a ratio when the specific gravity is converted to 1 is 60% or more A partial diffractive structure transfer sheet comprising: a heat-resistant mask layer comprising: an adhesive layer provided so as to cover a surface of the heat-resistant mask layer and a surface of the diffractive structure-forming layer without the heat-resistant mask layer; Providing manufacturing methods A.

The present invention according to claim 8 is a method for manufacturing a partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light, on a sheet-like support having heat resistance. Further, from the side close to the support, at least a heat-resistant protective layer that can be peeled off from the support, a transparent diffractive structure forming layer partially having a minute uneven surface for generating diffracted light, the unevenness A diffraction effect layer having a thin film provided on its surface , a thermoplastic resin having a glass transition temperature of 150 ° C. or higher so as to cover at least a region having the diffraction effect layer, and a ratio when the specific gravity is converted to 1 is 60% or more A partial diffractive structure transfer sheet comprising: a heat-resistant mask layer comprising: an adhesive layer provided so as to cover a surface of the heat-resistant mask layer and a surface of the diffractive structure-forming layer without the heat-resistant mask layer; Providing manufacturing methods A.

  As described above, according to the present invention, it is possible to provide a partially diffractive structure transfer sheet that has excellent heat resistance even after being attached to an article and that can be provided with a verification function, and a method for producing the same. It was.

  1 and 2 are sectional views showing an embodiment of a diffraction structure transfer sheet according to the present invention. As shown in FIG. 1 to FIG. 3, the diffraction structure transfer sheet according to the present invention includes at least a heat-resistant protective layer 2 on a support 1 and a diffraction structure forming layer having a minute uneven surface for generating diffracted light. 3. A configuration characterized in that a diffraction effect layer 4, a heat-resistant mask layer 5, and an adhesive layer 6 are provided at least partially.

  If this transfer sheet is used, it can be formed into almost any shape with a considerable degree of freedom for various articles using means such as hot stamping. That is, after the transfer material and the adhesive layer are bonded by applying heat and pressure, an unnecessary support is peeled off to form a medium for preventing forgery (not shown). )

  As the support 1, it is common to use a polyethylene terephthalate resin film having a stable thickness and high heat resistance, but is not limited thereto. As other materials, polyethylene naphthalate resin films, polyimide resin films and the like are known as films having high heat resistance, and can be used for the same purpose. In addition, other films such as polyethylene, polypropylene, heat-resistant vinyl chloride and the like can be used as long as coating conditions for the coating liquid, more specifically, drying conditions permit.

  In addition, when it is difficult to peel off the heat-resistant protective layer 2 due to transfer conditions or the like, a conventionally known release layer may be separately provided on the support side. Adhesion treatment may be performed to adjust the peeling. In addition, as long as there is no influence on the transfer layer, there is no problem with processing such as antistatic treatment, mat processing, and emboss processing.

  The heat-resistant protective layer 2 is a layer that is peeled off from the support 1, and more specifically, after being peeled off, the heat-resistant protective layer 2 is formed so as to cover the top of the diffractive structure forming layer 3. It is resistant to external damage such as rubbing, and living substances (such as liquor and water), and also serves to protect damage caused by external factors, and conventionally known protective materials having peelability are used.

  If the diffractive structure forming layer 3 itself is easily peeled from the support 1 and has sufficient resistance after transfer, it is not necessary to provide the heat-resistant protective layer 2. When the heat-resistant protective layer 2 is not provided, the diffractive structure forming layer and the heat-resistant protective layer are not separate layers, and the diffractive structure-forming layer itself also serves as a heat-resistant protective layer.

  Further, when the diffractive structure forming layer 3 itself can be easily peeled off from the support 1 and a separate protective layer can be provided after the transfer, it is not necessary to provide the heat resistant protective layer 2. And when this heat-resistant protective layer 2 is not provided, the diffractive structure-forming layer and the heat-resistant protective layer are not separate layers, and the diffractive structure-forming layer itself does not necessarily have sufficient resistance after transfer. A protective layer provided after the transfer protects the forgery prevention layer (in place of the heat-resistant protective layer). As described above, when the diffractive structure forming layer itself has peelability, it is not necessarily a representative example, but also corresponds to the embodiments of claims 1 and 2.

Next, the diffractive structure forming layer 3 that expresses the above structural color, which is the function / effect of OVD, will be described in a little more detail. As a medium that expresses a structural color, there is mainly a medium that exhibits an image using light interference, which is a display body that causes a color change (that is, color shifts) depending on the representation of a stereoscopic image and the viewing angle. Specific examples relating to this structural color include those using cholesteric liquid crystal as a material, OVD such as an optical multilayer interference film, a hologram, and a diffraction grating.

  Here, the cholesteric liquid crystal is a liquid crystal having a helical structure in which constituent molecules of an optically active liquid crystal are nematically uniaxially oriented in a thin layer, but are twisted at a certain angle in a certain direction with each other between adjacent layers. is there.

  The pitch of this spiral is distributed from several hundred nm to infinity. This helical structure causes the cholesteric liquid crystal to have a unique interaction with light. One is that the refractive index fluctuates periodically along the helix axis, and therefore selectively reflects light with a wavelength corresponding to the helix pitch, and the second depends on the handedness of the helix. It shows left circular polarization or right circular polarization and emits a brilliant color from blue to red. The third is to show a large optical rotation.

  Next, as for the optical multilayer interference film, it is composed of a multilayer optical thin film having different optical characteristics. Considering the viewpoint of the material, an appropriate number of layers are laminated as a metal thin film, a ceramic thin film, or a composite thin film formed by combining them, depending on the relationship between the optical characteristics of each layer and the combination of the layers. For example, when thin films having different refractive indexes are laminated, a thin film having a high refractive index and a thin film having a low refractive index may be combined, or a specific combination may be alternately laminated. An optical multilayer interference thin film that exhibits a desired optical effect (here, a structural color) can be obtained by an appropriate combination that satisfies the optical conditions of these layers.

  This multilayer thin film layer is made of a material such as ceramics or metal. A thin film having a high refractive index material having a number of layers of about 2 or more and a thin film having a refractive index of about 1.5 are each provided. It is appropriately laminated with an optically appropriate film thickness. Examples of materials used for this thin film are given below. However, the numerical value in the parenthesis following the chemical formula here indicates the respective refractive index n.

First, as ceramics, Sb ₂ O ₃ (3.0), Fe ₂ O ₃ (2.7), TiO ₂ (2.6), CdS (2.6), CeO ₂ (2.3), ZnS (2.3), PbCl ₂ (2.3), CdO (2.2), Sb ₂ O ₃ (2.0), WO ₃ (2.0), SiO (2.0), Si ₂ O ₃ (2.5), In ₂ O ₃ (2.0), PbO (2.6), Ta ₂ O ₃ (2.4), ZnO (2.1), ZrO ₂ (2.0), MgO ( 1.6), Si ₂ O ₂ (1.5), MgF ₂ (1.4), CeF ₃ (1.6), CaF ₂ (1.3 to 1.4), AlF ₃ (1.6) , Al ₂ O ₃ (1.6), GaO (1.7), and the like, and metal-based materials include Al, Fe, Mg, Zn, Au, Ag, Cr, Ni, Cu, Si Examples of simple metals or alloys such as That.

  Moreover, as a low refractive index material, for example, among organic polymers, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), Polystyrene (1.60) and the like. However, the numerical value in parenthesis shows each refractive index n here.

  By absorbing at least one kind from these high refractive index materials or 20% to 70% transparent metal thin films and at least one kind from low refractive index materials and alternately laminating them with a predetermined thickness, absorption for visible light of a specific wavelength is achieved. Or it comes to show reflection. In addition, since the optical characteristics such as the refractive index of the thin film made of metal vary depending on the state of the constituent material and the formation conditions, values in certain conditions are used in the embodiments of the present invention.

Each of the above materials is appropriately selected based on optical properties such as refractive index, reflectance, and transmittance, weather resistance, interlayer adhesion, and the like, and is laminated as a thin film to form a multilayer thin film. As a formation method, for example, a known method can be used, and a vacuum deposition method, a sputtering method, a CVD method, or the like that can control the film thickness, the film formation speed, the number of stacked layers, or the optical film thickness is appropriately used. It can be formed by use. Here, the optical film thickness is an amount given by n · d, n is the refractive index, and d is the film thickness.

  In addition, although it is not an optical multilayer interference film, even when using ink in which powder of reduced titanium dioxide-coated mica or iron oxide-coated mica, which is based on multiple reflection (scattering), is dispersed in a binder, subtle color changes depending on the viewing angle (Flip-flop effect) is given as an example.

  Furthermore, examples of the OVD such as a hologram and a diffraction grating include a relief type that records light interference fringes on a plane as a fine uneven pattern and a volume type that records interference fringes in a volume direction. In particular, in consideration of mass productivity and manufacturing cost, among these OVDs, a relief type hologram (or diffraction grating) is preferable because of its high suitability. The relief type described above is applied as the diffractive structure forming layer of the present invention.

  Relief-type holograms (or diffraction gratings) are produced by using a conventional optical imaging method, electron beam drawing, and induced surface relief forming method to produce a relief-type master plate consisting of fine concavo-convex patterns, Mass production is performed with a nickel press plate that has a pattern replicated by electroplating. That is, this press plate is heated and pressed against the diffractive structure forming layer 3 to replicate the uneven pattern on the surface.

Here, the induced surface relief forming method will be described. Irradiation with relatively weak light (a certain wavelength ranging from blue to green) of about several tens of mW / cm ² to an amorphous thin film of a polymer having azobenzene as a side chain. By doing so, movement of molecules occurs on a scale of several μm, and as a result, a relief is formed on the surface of the thin film.

  As a method for preventing forgery, a plurality of OVDs described above can be used in combination in the diffraction structure forming layer as long as the functions of the OVDs are not inhibited. Further, an OVD function may be separately provided between the heat-resistant protective layer 2 and the diffraction structure forming layer 3 (not shown).

  The diffractive structure forming layer 3 is a layer that expresses a structural color due to an optical phenomenon. In the case of a relief-type OVD, the diffractive structure forming layer 3 is required to be capable of being molded by a press plate, and its main material is thermoplastic. Any of resin, thermosetting resin, ultraviolet ray, or electron beam curable resin may be used. Examples of materials that can be used for the diffraction structure forming layer 3 include polyisocyanates such as thermoplastic resins such as acrylic resins, epoxy resins, cellulose resins, and vinyl resins, acrylic polyols and polyester polyols having reactive hydroxyl groups, and the like. As a cross-linking agent, UV resins such as melamine resins and phenol resins, UV or electron beam curable resins such as epoxy (meth) acryl, urethane (meth) acrylate, etc. Can be used in combination. Also, other than the above may be used as long as an OVD image can be formed.

  On the other hand, as these image technologies, a 3D hologram, which is a hologram that reproduces a three-dimensional image, or a special diffraction grating that expresses a diffraction grating with minute dots and can give a high radiance (the present inventors And so on).

  Recently, a method of forming each minute dot of the diffraction grating with an appropriate shape (for example, a star shape) or a minute character (so-called micro character) that cannot be seen with the naked eye by the minute dot of the diffraction grating. A method, a method that faithfully reproduces the color of a subject as if using a diffraction grating while using a diffraction grating, or a method that uses a diffraction grating to express a plurality of images that are completely different depending on the viewing angle (the present inventors, etc.) Are called changing).

  The present invention does not necessarily limit the image representation method of the OVD itself. In the present invention, not only the above-described image expression method but also a known image expression method can be used.

  Then, the diffraction effect layer 4 is a layer for effectively recognizing the OVD image provided in the diffraction structure forming layer 3, and either the reflection film 7 that appeals to the eye or the transmission film 8 or It is formed by two kinds of composites (FIGS. 3, 4, and 5). When the material used for the diffraction effect layer 4 is illustrated, in the case of the reflective film 7, a single metal material such as Al, Sn, Cr, Ni, Cu, or Au, or a compound thereof may be used.

  As the material of the diffraction effect layer 4 of the transmission film 8, it is necessary to use a high refractive index material having a higher refractive index than the material constituting the relief forming surface of the diffractive structure forming layer 3. The difference in refractive index is preferably 0.2 or more. Here, by taking a difference in refractive index of 0.2 or more, refraction and reflection occur at the interface with the diffractive structure forming layer 3, and the OVD effect can be obtained by good light reflection while having translucency. . That is, a visually effective hologram (or diffraction grating) can be obtained. As a material used here, the ceramic material of the multilayer thin film layer mentioned above can be used. Moreover, you may use the highly luminous light transmission ink which disperse | distributed the high refractive fine powder material whose particle diameter is 500 nm or less and whose refractive index is 2.0 or more in binder resin.

  These materials can be used alone or in layers, for example, after being provided with a film thickness of about 5 to 1000 nm by a thin film forming technique such as a known vacuum deposition method or sputtering method, and then by an appropriate method. If necessary, it is processed into a pattern.

  The following methods are mentioned as the method. After forming a desired pattern of a soluble resin in the diffraction structure forming layer 3 and providing a metal thin film, a method of washing and removing the soluble resin and the metal thin film layer of the portion, and an acid resistance to the metal thin film layer Or after printing a positive pattern using an alkali-resistant resin, the method of etching a metal thin film with an acid or an alkali is mentioned. Further, there is a method in which a resin material that dissolves or becomes difficult to dissolve is applied by exposure to light, and after exposure through a mask having a desired pattern shape, unnecessary portions are removed by washing or etching.

  In addition, a resin with poor adhesion is formed in a pattern on the diffractive structure forming layer, and after a metal thin film is provided, it is passed through an adhesive roll, etc., and the part is removed, or a mask is provided in the pot of the vapor deposition apparatus It is also possible to form a thin film partially. Another possible example is a technique in which only a thin film is physically removed by baking with a laser beam or the like. The above is an example, and the present invention is not limited to these. Any known technique for partially forming a metal thin film can be used as appropriate.

  Further, as a method other than the above-described thin film forming means, high-brightness light reflecting ink prepared by pulverizing aluminum or brass to 500 nm or less and dispersing it in a binder resin may be used. In this case, care must be taken not to attack the relief forming surface of the diffractive structure forming layer with a solvent, but it can be formed by known printing means such as gravure printing, flexographic printing, and screen printing. When the diffraction effect layer is provided by such a printing method, the film thickness after drying may be adjusted to be about 0.1 to 10 μm.

  The diffraction effect layer provided partially as described above may be, for example, a random pattern having no clear meaning, but information that is a pattern appropriately using any picture, figure, pattern, letter, number, symbol, etc. Information can be appropriately given by forming the pattern.

  Further, an optical multilayer interference film may be formed by combining a plurality of layers (two or more) of the light reflecting film 7 and the light transmitting film 8.

  Next, the heat resistant mask layer 5 will be described. The heat-resistant mask layer 5 is the most important layer in the present invention, and the relief shapes of the diffractive structure forming layer 3 and the diffraction effect layer 4 are caused by external thermal factors (for example, irons) that may occur in daily life. Even in the case of receiving a cliff, it plays the role of maintaining the relief shape.

  In order to achieve the above object, as a result of intensive studies by the authors, it has been concluded that it is important that the material of the heat-resistant mask layer contains at least 60% of a resin component having a glass transition temperature of 150 ° C. or higher. It was. When the glass transition temperature is less than 150 ° C., when heat from an iron or the like is applied, the crystalline state cannot be maintained, the heat-resistant mask layer itself is softened, and the relief shape cannot be maintained. In the heat-resistant mask layer, conventionally known various fillers, fillers, colorants and the like can be mixed up to 40% in addition to a resin having a glass transition temperature of 150 ° C. or higher. Here, the material is not particularly limited. The amount of addition will be described. When a colorant or the like is added in excess of 40%, the dispersibility is poor and the coating strength is lowered, resulting in poor heat resistance. Further, there are reasons such as poor printability (flowability of coating liquid, plate drying, etc.) and poor storage stability (precipitation, aggregation, etc.) of the coating liquid. 40% of the added amount is not a simple weight ratio but a ratio when the specific gravity is converted to 1. For example, in the case of adding precipitated barium sulfate (specific gravity 5.5), which is a white pigment, it is possible to add up to 220 parts by weight with respect to 60 parts by weight of the resin component having a specific gravity of 1.

  Next, the resin having a glass transition temperature of 150 ° C. or higher is preferably a thermoplastic resin that can be dissolved (or dispersed in an emulsion type) in a general-purpose solvent. Here, usable resins include polycarbonate resin (Tg. 140 to 150 ° C.), polyarylate resin (Tg. 193 ° C.), polysulfone resin (Tg. 190 ° C.), and polyether sulfone resin (Tg. 225 ° C.). , Polyetherimide resin (Tg. 200 ° C. or higher), cyclic polyolefin copolymer (Tg. 171 ° C.), modified norbornene resin (Tg. 171 ° C.), polyamideimide resin (Tg. 200 ° C. or higher), polyimide resin ( Tg. 250 ° C. or higher), but is not limited thereto. In addition, when there is no problem such as shrinkage, a thermosetting system, a moisture curing system, an ultraviolet curing system, an electron beam curing resin, or the like may be used.

  The heat-resistant mask layer 5 preferably has durability against acids and alkalis. The reason is that, as a means for partially providing the above-described diffraction effect layer 4, it is efficient to perform an etching process after providing the heat-resistant mask layer 5 (configuration in FIGS. 1 and 2). As an example of a general etching method, since it is immersed for 10 to 20 seconds in a 1.5 N NaOH solution heated to about 40 to 50 ° C., it is immersed in the coating film twice for about 40 seconds. If it does not change, it is judged that there is sufficient tolerance. The heat-resistant material described above has sufficient resistance to chemicals.

  Next, the adhesive layer 6 is a known heat sensitive resin (heat sensitive) having a function of adhering to the transfer material by applying heat and pressure in contact with various transfer materials (for example, paper / plastic). Adhesive material) is used. Note that, by appropriately adding a material having a verification function as described below to the adhesive layer 6, a verification function layer / adhesion layer which is an adhesive layer having a verification function can be obtained. As a result, it is possible to enhance the effect of anti-counterfeiting measures and obtain a different design.

The verification function is, for example, when an external stimulus (one or more of ultraviolet rays, infrared rays, etc.) is irradiated from the upper part where the image can be seen (depending on the light emitting material, for example, in the case of ultraviolet rays or infrared rays) The layer 2 emits light so that its presence can be confirmed, or when observed with infrared rays (for example, in the case of an infrared absorbing material), light is absorbed at that portion, so that its presence can be confirmed.

  Here, the materials that can be used for verification will be described in detail. As the luminescent material, visible light is emitted by an external stimulus, and ultraviolet, infrared, electron beam, X-ray, radiation, electric field, or Examples thereof include phosphors, phosphors, and daylights that emit light by an external stimulus such as a chemical reaction. The light emitting material is used by appropriately adding to a binder resin formed with the verification function layer 1. The addition amount is preferably within a range of 0.5% to 80%. When the addition amount is less than 0.5%, sufficient light emission cannot be obtained. When the addition amount exceeds 80%, the binding force with the binder resin is weakened, and the durability as a final product is weakened.

  Examples of the infrared absorbing material include a material having a wide absorption up to the visible region such as carbon black, and a material having an absorption wavelength in the infrared region and hardly absorbing visible light. The addition amount is desirably within a range of 0.5% to 80%. When the addition amount is less than 0.5%, sufficient absorption cannot be obtained. When the addition amount exceeds 80%, the binding force with the binder resin is weakened, and the resistance as the final product is weakened.

  Hereinafter, these light emitting materials will be described in more detail. The phosphor emits light in the vicinity of the visible range by external stimulation (excitation). In general, phosphors and phosphors are sometimes collectively referred to as phosphors. However, when distinguishing between phosphors and phosphors, phosphors having a relatively long afterglow are sometimes referred to as phosphors. Many. In particular, in many cases, the phosphor generally refers to a phosphor having an afterglow of an extent that can be perceived by the eye after excitation is stopped (approximately 0.1 sec).

  The daylight is generally a long afterglow with long afterglow. The following are mentioned as an example of a fluorescent substance. Ultraviolet-emitting fluorescent agents are those that are excited by ultraviolet rays and have spectral peaks in the blue, green, red, etc. wavelength range when returning to lower energy levels. After a trace amount of metal (copper, silver, manganese, bismuth, lead, etc.) is added as an activator in order to enhance the emission of light to a high-purity phosphor of sulfide, it can be obtained by high-temperature firing. These can adjust the hue, brightness, and degree of color attenuation by the combination of the base crystal and the activator.

  In addition, there are infrared emitting fluorescent agents, which are excited by infrared rays and emit light in the visible wavelength range (referred to as infrared visible conversion fluorescent agents), and excited by infrared rays. Some emit light in the longer wavelength range. The former infrared-visible conversion fluorescent agent is a phosphor having a very special excitation mechanism, and excites visible light emission by using a plurality of low-energy infrared photons.

There are two types of light emission mechanisms of these (the infrared visible conversion fluorescent agent and those that emit light in a longer wavelength region when excited by infrared rays), one of which is based on multi-stage excitation of activator ions, On the other hand, a plurality of resonance energy transmissions from the sensitizer each enable high excitation. The former type is observed in many host crystals that use Er ³⁺ or Ho ³⁺ as an activator, and the latter type absorbs infrared rays by the sensitizer Yb ³⁺ and emits light by multistage energy transfer. Of Er ³⁺ , Tm ³⁺ , Ho ³⁺ , etc. are excited to a high level. In addition, a semiconducting substance having a high electron mobility such as sulfide (ZnS, CdS) or oxysulfide (Y ₂ O ₂ S) as a base crystal and having photoconductivity is used as an electron beam-excited phosphor. It is possible to use.

In addition to ultraviolet rays and infrared rays, phosphors (Zn, Cd) S: Ag having high efficiency with respect to radiation such as X-rays or particle rays, and electroluminescent phosphors that directly change electric energy into luminescence are also included in the present invention. Can be cited as examples that can be used. Further, in addition to the above examples as fluorescent materials, organic pigments such as stilbene series such as diaminostilbenzyl sulfonic acid, diaminodiphenyl series, imidazole series, thiazole series, coumarin series, naphthalimide series, or thiophene series, etc. A dye may be used.

  Among these, for example, since it is relatively easy to manufacture or obtain a verification machine, a material that emits light by ultraviolet rays or infrared rays is preferable, and in particular, the former (light emitting material that emits light by ultraviolet rays) can be obtained at low cost. Even more preferable.

  Then, examples of the infrared absorbing material include phosphate-based white powder and sulfuric acid-based white crystal powder. Since these absorb the infrared rays without absorbing the visible rays, they appear white as a result of visual observation, but when the infrared rays are irradiated and the reflected light is observed, they are observed as an infrared absorbing material similar to carbon black.

  If black powder such as carbon black is dispersed in a binder, there is a problem that the presence can be easily confirmed visually, but the light-transmitting diffraction effect layer described above is transmitted. Since visible light is absorbed, the influence of sub-refraction and scattered light can be virtually ignored, and the function of the diffraction effect layer can be expressed more effectively. In addition, when using a white powder, it is difficult to visually determine the presence, and it is possible to separately provide a printing layer using a color material that has little influence on the spectrum of the reading wavelength, The width of the design will be expanded, and the design properties can be further improved.

  In addition to these examples, phthalocyanine-based infrared absorbing dyes can also be used. The above is an example, and the present invention is not necessarily limited to these, and infrared absorbing materials other than these may be appropriately studied and selected for use.

In addition to the above examples, the adhesive layer 6 to which the verification function is given may have several configuration examples as follows, and may be appropriately adopted. That is,
(A) A type that is used as a verification function layer 1 made of two or more layers by laminating a layer containing a light emitting material or a layer containing an infrared absorbing material either up or down. [Here, another layer (an anchor layer or the like for improving adhesion between the two layers) may be interposed between the two layers containing the light emitting material or the infrared absorbing material. Moreover, the location where the layers containing a light emitting material or an infrared rays absorption material are not laminated | stacked may exist partially. ]
(B) A type used as a verification function in which two or more layers are formed by providing two or more layers by arranging a layer containing a light emitting material and a layer containing an infrared absorbing material in a two-dimensional manner. [Here, the layers containing the light emitting material or the infrared absorbing material may be designed to be adjacent or not adjacent. In addition, the layers containing the light emitting material or the infrared absorbing material may have a portion that partially overlaps. ]
(C) A type in which a light emitting material or an infrared absorbing material is used as a verification function in a layer in which both materials are dispersed in the same layer. [For example, it can be obtained by coating after mixing light emitting material and infrared absorbing material. ]
(D) A type having a verification function by combining two or more of the above (a), (b), and (c).

  In more detail, in each of the cases (a) to (d), the invention is basically realized by a combination of a light emitting material (or a layer containing it) and an infrared absorbing material (or a layer containing it). Those are preferred. That is, as an example to be compared with this, (a) to (d) are each a combination of different light emitting materials (or layers containing them) or different infrared absorbing materials (or layers containing them). Combination types are also possible, and these can be manufactured. However, when the obtained effects are compared, the type of the combination of the former light emitting material (or the layer containing it) and the infrared absorbing material (or the layer containing it) is relatively superior in effect. Because.

  The effects referred to here are an effect that can obtain appropriateness for measures for preventing counterfeiting, and an effect that can obtain a visual beauty or an impression depth (in particular, the influence of light emission by the light emitting material is great).

  Further, other materials can be added as materials used for verification. For example, by using a magnetic material, a thermochromic material, a photochromic material, or the like as such a material, a light emitting material or an infrared absorbing material can be used in combination (for example, lamination or kneading) as appropriate. It is.

  Although one embodiment has been described above, it can be used as appropriate depending on the purpose of use, such as coloring each layer to improve the design or printing on the surface or between layers. Moreover, in view of the adhesiveness of each layer, it is possible to provide an adhesion anchor layer between each layer, and to perform various easy adhesion treatments such as corona discharge treatment, plasma treatment, and flame treatment.

<Example 1>
In this embodiment, the configuration of FIG. 1 will be described as a representative example.
A support 1 made of a transparent polyethylene terephthalate (PET) film having a thickness of 25 μm was provided as a heat-resistant protective layer 2 so that the film thickness after coating and drying was 2 μm. Next, as the diffractive structure forming layer 3, an ink composed of the following composition was applied so that the film thickness after baking and drying at 150 ° C. for 10 seconds was 1 μm. Next, after forming an OVD relief pattern (not shown) by a roll embossing method, aluminum was formed as a light-reflective diffraction effect layer 4 to a film thickness of 50 nm by a vacuum deposition method. Next, the ink which consists of the following compositions was pattern-printed as the heat-resistant mask layer 5, and it formed so that the film thickness after drying might be set to 1 micrometer. Next, the prepared transfer sheet (intermediate product) was etched by being immersed in a bath containing 1.5N NaOH solution heated to 50 ° C. for 10 seconds, and then neutralized with 0.1N HCl solution. Then, the diffraction effect layer 4 and the heat-resistant mask layer 5 which were partially formed as desired were obtained through a washing and drying process. Here, it was confirmed that the heat-resistant mask layer 5 exists only on the diffraction effect layer 4. Finally, using an ink composed of the following composition so as to cover the entire surface of the diffractive structure forming layer 3 and the heat-resistant mask layer 5, the adhesive layer 6 is formed so that the film thickness after coating and drying is 3 μm, The desired partial diffractive structure transfer sheet was obtained.

"Heat-resistant protective layer ink composition"
Acrylic resin (Tg. 105 ° C.) 19.2 parts by weight Polyethylene powder 0.8 parts by weight Methyl ethyl ketone 45.0 parts by weight Toluene 35.0 parts by weight “Diffraction structure forming layer ink composition”
Urethane resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight "Heat resistant mask layer ink composition"
Modified norbornene resin (Tg. 171 ° C.) 20.0 parts by weight Precipitating barium sulfate (specific gravity 5.5) 10.0 parts by weight Methyl ethyl ketone 40.0 parts by weight Toluene 30.0 parts by weight “Adhesive layer ink composition”
Vinyl chloride vinyl acetate copolymer resin 15.0 parts by weight Acrylic resin (Tg. 20 ° C.) 10.0 parts by weight Silica 1.0 part by weight Methyl ethyl ketone 44.0 parts by weight Toluene 30.0 parts by weight Evaluation was performed.

As a transfer material, hot stamping was performed on high-quality paper having a thickness of about 200 μm under two conditions of a plate surface temperature of 120 ° C. and a pressure of 2000 kg / cm ² and 140 ° C. and 1500 kg / cm ² (pressurization time was 0.3 seconds). The state of the OVD image was visually observed, and an OVD image that was changed in whitening, wrinkles, cracks, or the like was rated as x. Next, the attached OVD formation was immersed in soapy water (commercially available powdered soap in tap water at a concentration of 5%) for 10 minutes, and then heated through a patch using an iron heated to 200 ° C. (Iron weight: about 1.2 kg, 10 seconds). Here also, the state of the OVD image was visually observed, and the case where the OVD image was changed in whitening, wrinkles, cracks, or the like was rated as x. Finally, the transfer sheets prepared in Example 2 and Comparative Example 2 were verified. Here, using a 365 nm black lamp, the presence or absence of each fluorescent emission was confirmed before / after attachment to the transfer material. Here, the case where the emission of fluorescence could not be confirmed was marked as x. The results are shown in Table 1.

  As described above, Examples 1 and 2 have sufficient heat resistance not only after transfer but also after transfer. On the other hand, in Comparative Example 1, the OVD image was destroyed due to heat and pressure during transfer, and it could not be used. In Comparative Example 2, although it has sufficient heat resistance against heat and pressure at the time of transfer, the heat resistance after transfer is not sufficient, and it can withstand an iron test that is highly likely in a real life environment. It was not a thing. In addition, since the configurations of the first and second embodiments partially have a region for generating diffracted light, a verification function can be incorporated. In the case of Example 2, it was incorporated in the transfer sheet, but in Example 1, it can also be incorporated into the material to be transferred. In Comparative Example 2, the verification function was incorporated inside, but after being attached to the article, the function was inhibited by the reflective layer, and external verification was impossible.

<Example 2>
As Example 2, a partially diffractive structure transfer sheet was obtained with the same composition and processing as Example 1 except that the verification layer was included in the adhesive layer 6. The composition of the adhesive layer ink is described below.

"Adhesive layer ink composition"
Vinyl chloride vinyl acetate copolymer resin 12.0 parts by weight Acrylic resin (Tg. 20 ° C.) 8.0 parts by weight Inorganic fluorescent pigment 8.0 parts by weight Methyl ethyl ketone 46.0 parts by weight Toluene 26.0 parts by weight

<Comparative Example 1>
As Comparative Example 1, the transfer sheet in Example 1 was prepared with a conventional transfer sheet configuration excluding the heat-resistant mask layer 5 and the etching treatment.

<Comparative example 2>
As Comparative Example 2, a thermosetting resin composed of the following composition was applied over the entire surface of the diffraction effect layer (interlayer with the adhesive layer) of the transfer sheet prepared in Comparative Example 1. The film thickness after drying was adjusted to 1 μm, and heat treatment (aging) was performed for 1 week in an 80 ° C. environment before applying the adhesive layer 6. In Comparative Example 2, the adhesive layer containing the verification material of Example 2 was used.

[Thermosetting resin ink composition]
Acrylic polyol 15.0 parts by weight Epoxy resin 3.0 parts by weight Methyl ethyl ketone 52.0 parts by weight Toluene 30.0 parts by weight

  The present invention is a measure for preventing counterfeiting of securities such as gift certificates and credit cards, and a measure for preventing forgery to prove that it is a genuine product that is often applied to generally expensive items such as branded items and luxury items. , A technology suitable for these needs, and a technology capable of obtaining a visual effect excellent in decorativeness depending on the design, and an anti-counterfeit transfer sheet capable of obtaining a higher effect in combination with OVD, and its manufacture Regarding the method. It can be used as such.

FIG. 1 is a sectional view showing an embodiment of a partially diffractive structure transfer sheet according to the present invention. FIG. 2 is a sectional view showing an embodiment of a partially diffractive structure transfer sheet according to the present invention, which is different from the example of FIG. FIG. 3 is a cross-sectional view showing an embodiment of a partially diffractive structure transfer sheet according to the present invention, which is different from the examples of FIGS. FIG. 4 is a cross-sectional view showing an embodiment of a partially diffractive structure transfer sheet according to the present invention, which is different from the examples of FIGS. FIG. 5 is a cross-sectional view showing an embodiment of a partially diffractive structure transfer sheet according to the present invention, which is different from the examples of FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Support body 2 ... Heat-resistant protective layer 3 ... Diffraction structure formation layer 4 ... Diffraction effect layer 5 ... Heat-resistant mask layer 6 ... Adhesive layer 7 ... Reflective film 8 ...・ Transparent film

Claims (8)

A partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light,
On the sheet-like support having heat resistance, from the side close to the support, at least,
A heat-resistant protective layer that can be peeled off from the support, a transparent diffractive structure-forming layer having a minute uneven surface for generating diffracted light, a diffraction effect layer in which a thin film is partially provided on the uneven surface, at least A heat-resistant mask layer provided so as to cover the region where the diffraction effect layer is present, and an adhesive layer provided so as to cover the surface of the heat-resistant mask layer and the surface of the diffraction structure forming layer without the heat-resistant mask layer,
It has the above,
The partially diffractive structure transfer sheet, wherein the material of the heat-resistant mask layer contains 60% or more of a thermoplastic resin having a glass transition temperature of 150 ° C. or more in a ratio when the specific gravity is converted to 1 . A partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light,
On the sheet-like support having heat resistance, from the side close to the support, at least,
A heat-resistant protective layer that can be peeled off from the support, a transparent diffractive structure-forming layer partially having a minute uneven surface for generating diffracted light, a diffraction effect layer provided with a thin film on the uneven surface,
A heat-resistant mask layer provided so as to cover at least a region having the diffraction effect layer, and an adhesive layer provided so as to cover a surface of the heat-resistant mask layer and a surface of the diffraction structure forming layer without the heat-resistant mask layer,
It has the above,
The partially diffractive structure transfer sheet, wherein the material of the heat-resistant mask layer contains 60% or more of a thermoplastic resin having a glass transition temperature of 150 ° C. or more in a ratio when the specific gravity is converted to 1 .   The material of the heat-resistant mask layer has resistance to acid or alkali, is provided on the diffraction effect layer, and does not substantially exist on the diffraction structure forming layer. The partially diffractive structure transfer sheet according to any one of claims 1 and 2. Partial diffractive structure transfer sheet according to any of claims 1 to 3 noise insertion the thin film to be a reflection film for reflecting light, characterized by. Wherein the thin film is, the diffractive structure formed layer refractive index higher than that, it is transparent film having light transparency, partial diffractive structure transfer according to any of claims 1 to 3 noise insertion and wherein Sheet. The thin film has at least two types, one is a reflective film that reflects light, and the other is a transparent film having a refractive index higher than that of the diffractive structure forming layer and having light transmittance, and
The region where the reflective film is present and the region where the transparent film is present include at least regions different from each other, or at least the region of only the transparent film overlaps the reflective film and the transparent film. That there is a relationship with the area,
The partially diffractive structure transfer sheet according to any one of claims 1 to 3, wherein: A method for producing a partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light,
On the sheet-like support having heat resistance, from the side close to the support, at least,
A heat-resistant protective layer capable of being peeled off from the support,
A transparent diffractive structure forming layer having a minute uneven surface for generating diffracted light,
A diffraction effect layer in which a thin film is partially provided on the uneven surface;
A heat-resistant mask layer containing 60% or more of a thermoplastic resin having a glass transition temperature of 150 ° C. or higher so as to cover at least a region where the diffraction effect layer is present, and a specific gravity converted to 1 ; and
Providing an adhesive layer provided so as to cover the surface of the heat-resistant mask layer and the surface of the diffraction structure forming layer without the heat-resistant mask layer;
A method for producing a partially diffractive structure transfer sheet characterized by the following. A method for producing a partially diffractive structure transfer sheet for transferring a transfer layer partially provided with a region for generating diffracted light,
On the sheet-like support having heat resistance, from the side close to the support, at least,
A heat-resistant protective layer capable of being peeled off from the support,
A transparent diffractive structure forming layer partially having a minute uneven surface for generating diffracted light,
A diffraction effect layer provided with a thin film on the uneven surface;
A heat-resistant mask layer containing 60% or more of a thermoplastic resin having a glass transition temperature of 150 ° C. or higher so as to cover at least a region where the diffraction effect layer is present, and a specific gravity converted to 1 ; and
Providing an adhesive layer provided so as to cover the surface of the heat-resistant mask layer and the surface of the diffraction structure forming layer without the heat-resistant mask layer;
A method for producing a partially diffractive structure transfer sheet characterized by the following.