JP2009241404A - Recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording medium 10 having so high security properties that a latent image 105 is printed by using ink containing a fluorescent rare earth complex and using an ink-jet system without using an ink ribbon on which traces such as private information are left. <P>SOLUTION: The recording medium 10 is obtained by laminating at least a receptive layer 21 and a protective layer 15 on one surface of a base material 11. The receptive layer 21 comprises at least a cationic urethane resin, a cationic fixing agent and a filler. The latent image 105 is formed on the receptive layer 21 by using the ink containing the fluorescent rare earth complex and using the ink-jet system. The receptive layer 21 comprises the cationic urethane resin, the cationic fixing agent and the filler and the latent image 105 is a color image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording medium, and more specifically, an image can be printed by an ink jet method that does not use an ink ribbon that leaves traces of personal information or the like, and a latent image by an ink jet method that uses an ink containing a fluorescent light-emitting rare earth complex. The present invention relates to a high-security recording medium in which a visible image is formed by an information printing layer by an ink jet method, if necessary.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. In addition, “PET” is “polyethylene terephthalate”, “UV” is “ultraviolet”, “ionizing radiation curable resin” is “a general term for uncured ionizing radiation curable resin and cured ionizing radiation curable resin”, “Print” is an abbreviation, functional expression, common name, or industry term for “print”.

(Main use) The main use of the recording medium (medium) of the present invention is, for example, banknotes, stock certificates, securities, certificates, gift certificates, checks, bills, admission tickets, passbooks, gift certificates, tickets, cars Horse betting tickets, stamps, stamps, appreciation tickets, admission cards, pass cards, tickets, etc., cash cards, credit cards, ID cards, prepaid cards, cards such as IC cards, optical cards, greeting cards, postcards, Various certificates such as business cards, driver's licenses, passports, certification photographs, packaging materials such as cartons, cases, flexible packaging materials, bags, cosmetics, watches, brand accessories such as watches, lighters, envelopes, tags, bookmarks, Calendars, posters, brochures, nameplates, report paper and other stationery, building materials, panels, emblems, keys, cloth, clothing, footwear, radio , There is a TV, a calculator, such as devices such as OA equipment.
However, it is particularly limited as long as it has a high security and has a latent image image by an ink jet method and requires durability such as light resistance, weather resistance, abrasion resistance and solvent resistance. It is not something.

(Background Art) Conventionally, since the vouchers, cards, and various certificates have qualifications and certain economic values and effects, the owner's personal information is displayed. In addition, durability against external force during use is required. As a display method of personal information, printing (display) by a thermal transfer method is widely used. In these thermal transfer methods, various images are easily formed, and therefore, the thermal transfer method is used to create a printed material that requires a relatively small number of prints, for example, an ID card such as an identification card. Further, when a color image is preferable such as a face photograph, a large number of colored thermal transfer layers of, for example, yellow, magenta, and cyan (and black if necessary) are repeatedly provided in the surface sequence on a continuous base film. A thermal transfer method using a long thermal transfer film has been performed. There are two types of such thermal transfer films: a melt transfer type and a sublimation type thermal transfer film, both of which print using a dedicated ink ribbon. The missing portion of the discharged ink ribbon is personal information to be kept secret, and there is a risk that the personal information is easily known from the discarded ink ribbon.
Also, when creating ID cards such as identification cards with the above-mentioned thermal transfer film, it is easy to form images such as letters and numbers in the case of a melt transfer type thermal transfer film, but these images are durable. There is a drawback that the properties, particularly the friction resistance, are inferior. On the other hand, in the case of a sublimation transfer type thermal transfer film, a gradation image such as a face photograph can be formed, but unlike a normal printing ink, the formed image has no vehicle, so There exists a problem that it is inferior to durability, such as a weather resistance and friction resistance. As a method for solving the above problem, after forming an image, a protective layer such as a transparent resin layer or a cured resin layer is further formed on the surface of the image (corresponding to the protective layer, hard coat layer, and hologram layer of the present invention). There is a method for transferring the images. However, since the image transfer and the protective layer transfer are performed twice, it is complicated and inefficient. Therefore, there are some recording media that do not use an ink ribbon and form an image by an ink jet method. However, in an image by an ink jet method, the drying speed is slow, the image forming speed becomes slow, the printed image is blurred, and further, the image is printed. Since drying is slow, there is also a problem that it cannot be immediately transferred to the transfer target. Furthermore, since cards and various certificates have credential and certain economic value and effect, the owner cannot be easily identified, and impersonation can be used by anyone other than the owner through counterfeiting. There were also drawbacks.
Therefore, the recording medium does not use an ink ribbon that leaves traces of personal information or the like, and when printing an image on the recording medium, the image does not blur, dries quickly, light resistance, weather resistance, abrasion resistance, Durability such as solvent resistance is required, and security is also required to prevent counterfeiting, alteration, and spoofing.

(Prior Art) Conventionally, a card is known in which an image is formed on an image receiving layer by sublimation thermal transfer, melt thermal transfer, ink jet, or electrophotography, and transferred onto a substrate by thermal transfer (see, for example, Patent Document 1). ). However, there is a problem that an image by ink jet is an image such as a character and does not have special security.
Further, on one side of the support, a release layer, a first hologram forming layer having a hologram pattern, a transparent thin film layer, a second hologram forming layer having a hologram pattern different from the first hologram forming layer, reflection In a hologram transfer foil formed by sequentially laminating a transparent thin film layer and an adhesive layer, a printed layer is formed between the transparent thin film layer and the second hologram forming layer so as to cover at least a part of the transparent thin film layer In addition, a hologram transfer foil in which at least a part of the printed layer is printed with fluorescent ink is known (see, for example, Patent Document 2). However, the fluorescent ink is not an ink jet method, and it is a known printing method and cannot handle a small lot. Furthermore, there is a drawback that it is extremely difficult to print an image that is variable information on personal information or on demand.
Furthermore, it is provided on the support, the peelable protective layer, and the peelable protective layer having the same effect without using the fluorescent ink, and an image is provided based on the image data, and the substrate of the image display body is provided. In the intermediate transfer sheet provided with an image receiving / adhesive layer having thermal adhesiveness, the image receiving / adhesive layer has a partial thickness difference, and a counterfeit prevention measure that causes a difference in recognition color due to an optical interference phenomenon at that portion. An intermediate transfer sheet subjected to is known (for example, see Patent Document 3). However, the structure having the optical interference phenomenon due to the difference in thickness has a drawback that it is expensive and expensive because it is complicated and complicated.
Further, the applicant of the present invention provides a thermal transfer sheet (corresponding to the recording medium of the present invention) in which a thermal transfer sheet substrate, a release layer, a water-resistant resin layer, a water-based ink receiving layer, and an inkjet printing layer are sequentially formed, and the thermal transfer sheet. A card manufacturing method for thermally transferring a sheet to a card material is disclosed (for example, see Patent Document 4). However, although it is possible to form a clear original image composed of a personal photograph of an individual possessed or a design or design of the user's preference, there is a drawback in that security is low to prevent forgery, alteration and spoofing.
Furthermore, the present applicant superimposes a fluorescent latent image transfer film provided with a fluorescent ink layer on a heat-resistant substrate film on an intermediate transfer medium, and the fluorescent ink layer of the fluorescent latent image transfer film is formed into a desired pattern by a heating element. And forming a fluorescent latent image made of fluorescent ink on the intermediate transfer medium, and then transferring the fluorescent latent image of the intermediate transfer medium to the transfer medium to disclose a printed material and a fluorescent latent image forming method. (For example, refer to Patent Documents 5 to 6.) However, after heating the fluorescent latent image transfer film in a desired pattern with a heating element and transferring the fluorescent ink layer to an intermediate transfer medium, the fluorescent latent image transfer film has a portion of the latent image that has been printed and missing. The remaining film of the image transfer film is discharged and discarded, and this missing part is personal information that you want to keep secret, but there is a disadvantage that personal information etc. will be known by irradiating ultraviolet rays, and furthermore, the fluorescent latent image Since the security pattern is composed of a fluorescent material layer and an ultraviolet absorption pattern provided in a pattern above the fluorescent material layer, it is a monochrome tone image and a color latent image cannot be printed. is there.
Furthermore, as a phosphor, a transfer foil in which a fluorescent light-emitting layer containing an optically active rare earth complex and an adhesive layer are laminated on a temporary support film, and an optically active rare earth complex on one side of the support film. A label having a fluorescent light-emitting layer to be contained and an adhesive layer on the other side is known (for example, see Patent Documents 7 to 8). However, although there is a description that the fluorescent light emitting layer may be formed by an ink jet method, there is no suggestion or description about a receiving layer for fixing the fluorescent light emitting layer, and there is a problem that the fluorescent light emitting layer does not fix to water non-absorbing plastic films. There is.

Japanese Patent Laid-Open No. 10-244788 JP-A-7-199781 JP 2007-1163 A JP 2006-2054889 A JP 2000-2111255 A JP 2000-168243 A JP 2005-111704 A JP 2005-112947 A

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is not to use an ink ribbon that leaves traces of personal information, etc., but when printing an image on a recording medium, the image does not bleed, it dries quickly, light resistance, weather resistance, abrasion resistance and solvent resistance It is another object of the present invention to provide a high-security recording medium that is required to have durability such as security and to prevent forgery, alteration, and spoofing.

In order to solve the above problems, a recording medium according to the invention of claim 1 is a recording medium in which a base material and at least a receiving layer and a protective layer are laminated on one surface of the base material, The receiving layer includes at least a cationic urethane-based resin, a cationic fixing agent, and a filler, and a latent image is formed by an inkjet method using an ink including a fluorescent light-emitting rare earth complex in the receiving layer. It is what you did.
A recording medium according to a second aspect of the invention is such that an information printing layer is formed on the receiving layer by an ink jet method in addition to a latent image.
A recording medium according to a third aspect of the invention is such that the latent image is a color image.
A recording medium according to a fourth aspect of the invention is such that a hard coat layer or a hologram layer and a transparent reflection layer are used in place of the protective layer.

According to the first aspect of the present invention, when an image is printed on a recording medium without using an ink ribbon that leaves traces of personal information or the like, the image does not blur, dries quickly, light resistance, weather resistance, A recording medium having high durability such as rubbing and solvent resistance and high security is provided.
According to the present invention of claim 2, in addition to the effect of claim 1, an information printing layer associated with the latent image can be formed, and a recording medium with higher security that prevents forgery, alteration, and impersonation is provided. Is done.
According to the third aspect of the present invention, in addition to the effects of the first and second aspects, the latent image is a color image, and a recording medium with higher security is provided.
According to the fourth aspect of the present invention, in addition to the effects of the first to third aspects, a recording medium having high durability such as abrasion resistance and solvent resistance is provided after the image is transferred to the transfer medium. Is done.

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 recording medium showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a recording medium showing one embodiment of the present invention.

  (Recording medium) As shown in FIG. 1, the recording medium 10 of the present invention has a base material 11 and a receiving layer 21 and a protective layer 15 on one surface of the base material 11. A latent image 105 is formed (printed) by an inkjet method using an ink containing at least a cationic urethane-based resin, a cationic fixing agent, and a filler, and containing a fluorescent light-emitting rare earth complex in the receiving layer 21. The protective layer 15 is formed after the latent image 105 is provided on the receiving layer 21. Further, instead of the protective layer 15, a hard coat layer 25 (not shown) or a hologram layer 35 and a transparent reflective layer 37 as shown in FIG. 2 may be used. Further, the latent image 105 is preferably a color image composed of RGB. Furthermore, in addition to the latent image 105, a visible image 103 is preferably formed on the receiving layer 21 by an inkjet method, which is also illustrated in FIG.

  (Other layers) Moreover, you may provide another layer in these interlayers and / or the layer surface as needed. Examples of the layer provided on the interlayer and / or the layer surface as needed include a primer layer, a printing layer, an antistatic layer, a back-sliding layer, and the like, and may be known ones.

  (Substrate) The substrate 11 is not particularly limited. For example, natural fiber paper, coated paper, tracing paper, plastic film or sheet that is not deformed by heat during transfer, glass, metal, ceramics, wood, Any material such as cloth may be used. In addition, at least a part of the base material 11 may be colored, printed, or otherwise decorated, and the protective layer may also be printed or otherwise decorated.

  (Primer layer) It is preferable to provide a primer layer 16 in order to improve the adhesive strength with the substrate 11 as required. Examples of the primer layer 16 include polyurethane resins, polyester resins, polyamide resins, epoxy resins, phenol resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymers, Acid-modified polyolefin resins, copolymers of ethylene and vinyl acetate or acrylic acid, (meth) acrylic resins, polyvinyl alcohol resins, polyvinyl acetal resins, polybutadiene resins, rubber compounds, etc. can be used. Preferably, those having oxygen or nitrogen, or those having a reactive isocyanate compound, such as those known as conventional adhesives such as acrylic resins, urethane resins, amide resins, epoxy resins, ionomer resins, rubber resins, etc. is there. The primer layer is not necessarily contained since it has a thin film thickness, but it is preferable to contain a filler such as microsilica or polyethylene wax.

  (Receiving layer) A receiving layer 21 is provided on the surface of the substrate 11 with a primer layer 16 as necessary, and an image is printed on the receiving layer 21 by an ink jet method. The receiving layer 21 may be a known one, but preferably contains a cationic urethane resin, a cationic fixing agent, and a filler.

  Polycationic polyurethane resins with cationic groups, polytetramethylene ether glycol polyurethane, polyester ether polyurethane, polybutylene adipate polyurethane, polymethylpentane adipate polyurethane, polynonanediol adipate / polyoctane adipate Polyurethane resins such as polyurethane and polymethylpentane adipate polyurethane, preferably self-emulsifying or aqueous, and a reaction product of a polycarbonate or polyester polyol having a cationic hydrophilic group and an aliphatic isocyanate. Examples of cationic groups include primary to tertiary amines or quaternary ammonium bases. Examples of the cationic fixing agent include dye fixing agents such as polyamine derivatives and quaternary ammonium salts. As the filler, fine silica or wax such as silica, alumina, calcium carbonate, plastic pigment, or the like, which is included so as to improve the foil cutting property and do not impair the transparency, is preferable.

  The ratio of the cationic urethane-based resin, the cationic fixing agent, and the microsilica is cationic urethane-based resin: cationic fixing agent: microsilica = 100: 5 to 20: 1-10 on a mass basis. If the content of the cationic fixing agent is less than the above range, the fixing property is poor, and if it exceeds the above range, it elutes during washing and lowers the fastness. If the content of microsilica is less than the above range, the ink fixing property and foil sharpness are poor, and if it exceeds the above range, the transparency is lowered and the image becomes difficult to see.

  (Fixability) The conventional receiving layer is mainly composed of a water-soluble resin such as polyvinyl alcohol, and its water resistance is remarkably poor. Also, a porous filler is used, or a good solvent is used as a solvent for the receiving layer coating solution. And a poor solvent, and phase separation and gelation during drying to form a porous network structure, but there is a problem that the image is not sufficiently fixed and the image becomes light during washing. It was. According to the receiving layer 21, both the latent image 105 and the visible image 103 printed by the ink jet method have high image quality and good fixability, and the fastness to washing is improved. Although coexistence of fixability and fastness to washing is not clear, the inclusion of a cationic urethane resin, a cationic fixing agent, and a filler makes the surface of the coating film fine irregularities, and the coating itself aggregates Since the state is not very dense but rather rough, the permeability and adhesion of the image components are improved, and the dyes that make up the image react with the cationic urethane resin and the cationic fixing agent to insolubilize. In order to do so.

  (Protective layer) Although it does not specifically limit as the protective layer 15, For example, it is resin, such as a polyester-type resin, a polyamide-type resin, a vinyl chloride resin, a (meth) acrylic-type resin, These copolymers are made into a main component It may be a resin or a mixture (including an alloy). If necessary, for example, colorants such as lubricants, plasticizers, fillers, antistatic agents, antiblocking agents, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, dyes, pigments, etc. Additives and the like may be added. What is necessary is just to apply | coat with the well-known roll coat method and the gravure coat method, and to dry so that these may be ink-ized and the thickness after drying may be set to about 1-50 micrometers. Moreover, as the protective layer 15, you may form by an inkjet system and what hardens | cures by irradiation of an ultraviolet-ray after inkjet printing is preferable. Furthermore, the protective layer may be formed by a transfer method using a separate protective layer transfer foil, and of course, a known printing method such as offset printing, gravure printing, or screen printing may be used.

  (Hard Coat Layer) In the present invention, by using the hard coat layer 25 instead of the protective layer 15, it is positioned on the outermost surface and exhibits durability such as abrasion resistance and solvent resistance. The hard coat layer 25 contains at least an ionizing radiation curable resin as a main component and contains polyethylene wax. The ionizing radiation curable resin is preferably (1) an isocyanate having three or more isocyanate groups in the molecule, and (2) at least one hydroxyl group and at least two (meth) acryloyloxy groups in the molecule. Using an ionizing radiation curable resin containing a urethane (meth) acrylate oligomer which is a reaction product of a polyfunctional (meth) acrylate having a polyhydric alcohol having at least two hydroxyl groups in the molecule, or (3) A wax may be included, applied, dried, and cured with ionizing radiation to form an ionizing radiation curable resin.

  (Hologram Layer) In the present invention, the hologram layer 35 and the transparent reflection layer 37 can be used in place of the protective layer 15 to impart high designability and anti-counterfeiting property of the hologram. As shown in FIG. 2, the layer structure is substrate 11 / primer layer 16 / receiving layer 21 / adhesive layer 19 / reflection layer 37 / hologram layer 35. Since the hologram layer 15 uses a cured product of an ionizing radiation curable resin similar to or the same as the hard coat layer, it has the function of a hard coat layer and is two birds with one stone. The hologram layer 35 may be formed once by transferring to the surface of the receiving layer 21 as a hologram transfer foil.

  (Hologram layer) The hologram layer 35 may contain a cured product of ionizing radiation curable resin and reactive silicone, and may also contain polyethylene wax in addition to them. This makes it possible to transfer a hologram with excellent heat resistance that does not whiten by heat even after ionizing radiation curing, excellent conformability to expansion and contraction, and less deterioration of hologram effects such as cracking and whitening to a three-dimensional surface. be able to. For example, an epoxy-modified acrylate resin, a urethane-modified acrylate resin, an acrylic-modified polyester, or the like can be applied to the hologram layer 35. Preferably, an ionizing radiation curable resin such as a urethane-modified acrylate resin, and if necessary, an additive to a solvent. It may be dispersed or dissolved and applied to at least one part by a known coating method such as roll coating, gravure coating, comma coating, etc. and dried to form a coating film. The thickness of the hologram layer 35 is usually about 1 μm to 30 μm, preferably about 2 μm to 20 μm. It may be applied several times.

  (Hologram) Next, on the surface of the hologram layer 35, a predetermined relief structure such as a hologram that exhibits a light diffraction effect is formed and cured. A hologram is a recording of interference fringes due to the interference of light between object light and reference light in an uneven relief shape, such as 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. The relief shape is a concavo-convex shape, and is not particularly limited, and may have a fine concavo-convex shape such as light diffusion, light scattering, light reflection, light diffraction, etc., such as Fourier transform or lenticular lens. , A light diffraction pattern, and a moth eye. Further, although it does not have a light diffraction function, it may be a hairline pattern, a mat pattern, a line pattern, an interference pattern, or the like that expresses a unique glitter. As a method for producing these relief shapes, in addition to holograms and diffraction gratings produced using hologram photographing and recording means, holograms produced using an electron beam drawing device based on optical calculations such as interference and diffraction, A diffraction grating can also be mentioned. Also, a relatively large pattern such as a hairline pattern or a line pattern may be a machine cutting method. These holograms and / or diffraction gratings may be recorded single or multiple, or may be recorded in combination.

  The relief shape is shaped (also referred to as replication) on the surface of the hologram layer 35. Hologram shaping can be formed by a known method. For example, when recording diffraction gratings or interference fringes of holograms as reliefs of surface irregularities, a master on which the diffraction gratings or interference fringes are recorded in irregularities is pressed. The concave / convex pattern of the original can be duplicated by using it as a mold (referred to as a stamper) and by superimposing the original on the resin layer and heat-pressing both of them with an appropriate means such as a heating roll.

  Further, the hologram pattern formed on the hologram layer 35 may be single or plural. When providing a plurality of hologram patterns, it is preferable to provide a hologram mark (timing mark) for each hologram pattern. When the hologram mark (timing mark) is detected and an image is formed by an inkjet method described later, the hologram pattern and the inkjet image can be formed in synchronization, and the design of the synchronized hologram image and print image The effect and security can be further improved. The hologram layer 35 is irradiated with ionizing radiation during or after embossing with a stamper to cure the ionizing radiation curable resin. The ionizing radiation curable resin becomes an ionizing radiation curable resin (hologram layer 35) when it is cured (reacted) by irradiation with ionizing radiation such as ultraviolet rays or electron beams after the relief is formed.

(Transparent Reflective Layer) Since the transparent reflective layer 17 is provided on the transparent reflective layer 17 on the relief surface of the hologram layer 15 provided with a predetermined relief structure, the reflection and / or diffraction effect of the relief is enhanced. If the reflectance of 15 is higher, it is not particularly limited. The transparent reflecting layer 17 has a substantially colorless and transparent hue, and its optical refractive index is different from that of the hologram layer. A simple hologram can be produced. For example, there are a thin film having a higher refractive index than the hologram layer 15 and a thin film having a lower refractive index. Examples of the former include ZnS, TiO ₂ , Al ₂ O ₃ , Sb ₂ S ₃ , SiO, SnO _2. ITO, etc., and examples of the latter include LiF, MgF ₂ , and AlF ₃ . Preferably, it is a metal oxide or nitride, specifically, Be, Mg, Ca, Cr, Mn, Cu, Ag, Al, Sn, In, Te, 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 when it has a thickness of 200 mm or less. The transparent metal compound is formed on the relief surface of the hologram layer 15 by vacuum such as vapor deposition, sputtering, ion plating, and CVD so that the thickness of the relief layer of the hologram layer 15 is about 10 to 2000 nm, preferably 20 to 1000 nm. It may be provided by a thin film method or the like.

  (Durability) As described above, when the hard coat layer 25 or the hologram layer 35 and the transparent reflective layer 37 as shown in FIG. 2 are used instead of the protective layer 15, these layers become the outermost surfaces. . As the visible image 103 by the ink jet method, when an ID card such as an ID card is created, the image can be easily formed. However, the image formed on the surface of the receiving layer 21 has durability, particularly friction resistance. There is a disadvantage of being inferior. By providing the printed receiving layer 21, the highly durable hard coat layer 25 or the hologram layer 35 is positioned on the outermost surface to protect the image and enhance the durability.

  The pencil hardness test of the hard coat layer 25 and the hologram layer 35 is measured according to JIS-K5400, and a hardness of H or higher is preferable. The scratch strength is 150 g or more, preferably 200 g or more, from the viewpoint of sufficient friction resistance on the surface. The scratch strength was measured using a wear resistance tester (HEIDON-18) on a sample conditioned at 23 ° C. and 55% RH for 24 hours, with a 0.8 mmφ sapphire needle at a right angle. As a result, the load applied to the sapphire needle was gradually increased from 0 g to 200 g, and the load when the surface began to be scratched was measured while sliding and moving the sample surface at 60 cm / min. The larger the load, the better.

(Inkjet system) The latent image 105 may be formed (printed) on the receiving layer 21 of the recording medium 10 of the present invention by the inkjet system and, if necessary, the visible image 103 by the inkjet system. The latent image 105 may be formed by an ink jet method using an ink containing a fluorescent light-emitting rare earth complex. The ink jet method includes a thermal impact method, but is not particularly limited. The visible image 103 may be a known aqueous or oily ink, and may be formed by an inkjet method using a dye-based, pigment-based or combined-type colored inkjet ink.
The latent image 105 and / or the visible image 103 formed by the ink jet method may have a spot shape such as a circle or a star, or any shape such as a letter, a number, an illustration, and a photograph. It is not limited for full color use. Preferably, the variable information is printed by an inkjet method on demand.

  When a hologram is also provided when forming the latent image 105 and / or the visible image 103 by an inkjet method, a hologram mark (timing mark) corresponding to the hologram pattern is provided, and the hologram mark (timing mark) ) And the inkjet image can be formed in synchronization with the hologram pattern, and the design effect and security of the synchronized hologram image and the printed image can be further improved as necessary. .

  In the inkjet method, when the latent image 105 and / or the visible image 103 is printed, an ink ribbon that leaves traces of personal information or the like is not used, and the latent image 105 and / or the visible image 103 is printed. In this case, the use of the receiving layer 21 containing a cationic urethane resin, a cationic fixing agent, and a filler prevents the image from blurring and is quick to dry.

  (Inkjet visible image) The inkjet method for forming the visible image 103 includes a thermal impact method, but is not particularly limited. The inkjet ink is also a known water-based or oil-based ink, and a dye system, a pigment system, or a combined system can be used. There is no particular limitation.

  (Inkjet latent image) The ink used in the inkjet method for forming the latent image 105 is an ink containing a fluorescent light-emitting rare earth complex. Conventionally, a phosphor is generally used as a material that is converted into light such as visible light by irradiating excitation rays such as ultraviolet rays, infrared rays, and electron beams. However, since the particles are large, the luminous efficiency is low. Due to the danger of nozzle clogging and the like, there is a problem in using the ink jet method, and it is limited to a general printing method.

  Therefore, by converting the fluorescent light-emitting rare earth complex into a phosphor ink, the luminous efficiency is increased and the resin is dissolved in the resin, so that any nozzle image can be formed without clogging the nozzle. it can. The image formed by printing with the phosphor ink is normally not visible and becomes a latent image 105, but the latent image 105 emits visible light to be visualized by being irradiated with excitation light so that it can be visually observed. Therefore, the image has the effect of a hidden image, and the anti-counterfeiting property can be further improved in addition to the hologram. The excitation light is a phosphor excitation source that emits excitation light having a wavelength corresponding to the absorption wavelength of the phosphor, and examples thereof include an ultraviolet LED, a black light, a xenon lamp, and a short wavelength semiconductor laser.

  (Colorization) In addition, if a plurality of inks using a fluorescent light-emitting rare earth complex that emits RGB light is used and formed by an inkjet method, the latent image 105 can be visualized in color or photographic tone. The latent image 105 that has conventionally been a monochrome image can be displayed in color or photographic tone, the design can be improved, and the security such as further prevention of forgery can be improved. In addition, if the latent image 105 is used to form a photo of the owner's face, it cannot be seen by a malicious impersonator, can be visualized at the time of use and compared with the person, and can immediately be found to be different from the owner. it can. For example, if the owner name is provided in both the latent image 105 and the visible image 103 and the associated latent image 105 and the visible image 103 are provided, the forged medium can only forge the visible image 103 and is invisible. Since the latent image 105 cannot be created, it does not emit light even when it is irradiated with ultraviolet rays.

(Fluorescent light-emitting rare earth complex) A fluorescent light-emitting rare earth complex is an optically active rare earth complex that emits fluorescence, which is a rare earth complex having an optically active site. One of the two stereoisomers (Δ isomer, Λ isomer) of the rare earth complex or the tetragonal prismatic coordination structure of the rare earth complex that exists in terms of the absolute configuration around the rare earth metal atom. The rare earth complex in the state contained in The rare earth complex having such a structure has excellent emission characteristics and a sharp emission spectrum with a narrow half-value width. In particular, rare earth complexes in which the rare earth ion Ln ³⁺ is any one of Eu ³⁺ , Tb ³⁺ , Yb ³⁺ , Nd ³⁺ , Er ³⁺ , Sm ³⁺ , Dy ³⁺ , and Ce ³⁺ are weakly excited. It is a strong light-emitting rare earth complex that emits strong light even with light, and is preferably used. For example, there are general formula (1), general formula (2), general formula (3), and general formula (4). The rare earth complex preferably contains a <—C _n F _{2n + 1} (n is an integer of 1 to 22)> group from the viewpoint of heat resistance and stability. Specific examples include Lumisys (registered trademark, total distributor: Central Techno Co., Ltd., manufacturer: Nissei Chemical Industry Co., Ltd.) R-600, G-900, YB-1200, and the like. Details are described in WO2005 / 044770, JP2006-249075A, and JP2005-97240A.

（式中、Ｄは重水素原子、ハロゲン原子又は水素原子を含まないＣ１〜Ｃ２２の脂肪族基を示す）

(Wherein D represents a C1-C22 aliphatic group containing no deuterium atom, halogen atom or hydrogen atom)

(Wherein X represents C—R or N, and R represents a hydrogen atom or a substituent)

  (Ink) The fluorescent light-emitting rare earth complex may be dissolved and / or dispersed in a binder or a solvent to form an ink jet ink, or the ink may be kneaded with a fluorescent light-emitting rare earth complex. Additives may be added. Known resins can be used as the binder resin. It is preferable that there is no or small absorption in the absorption wavelength region of the fluorescent light-emitting rare earth complex and the fluorescence emission wavelength region. For example, a cellulose resin, a butyral resin, a polyvinyl alcohol resin, a polyester resin, an acrylic resin, or a polyurethane resin can be used alone or as a mixture. The solvent is not particularly limited as long as it is a solvent that dissolves the binder resin, and examples thereof include water, alcohols such as ethanol, ketones, and cellosolves. The ratio of the fluorescent light-emitting rare earth complex contained in the binder resin is about 0.01 to 10%, preferably 0.1 to 5%, based on mass. If it is less than this range, the intensity of the fluorescence emission is small, and if it exceeds this range, the intensity of the fluorescence emission is sufficient and the cost is high.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.

(Example 1) (1) First, as a base material 11, a primer layer 16 having a thickness of 1 μm and a receiving layer 21 having a thickness of 5 μm are formed on one side of a wound white PET film having a thickness of 188 μm. Using the composition composition working solution, it was sequentially applied, dried and laminated. The primer layer 16 and the receiving layer 21 were formed by a gravure coating method and a roll coating method, respectively, to obtain a recording medium.
・ <Primer layer composition working solution>
Polyester resin 10 parts by mass Vinyl chloride-vinyl acetate copolymer 10 parts by mass Solvent (MEK: Toluene = 1: 1) 80 parts by mass <Receptive layer composition working solution (pH = 3.5)>
Quaternary ammonium salt type polycarbonate-based polyurethane 20 parts by mass Dunfix 505RE (manufactured by Nitto Boseki Co., Ltd .; polycationic fixative agent) 2 parts by mass Microsilica (average particle size 0.5 μm) 1 part by mass Solvent (water: IPA = 3 1) 80 parts by mass The recording medium was punched into a size of 54 mm × 85 mm to obtain a white card for a membership card.
The printing operation and the transfer operation of the protective layer were performed in-line using the inkjet printer with a built-in protective layer transfer to the white card.
First, Lumisys R-600, G-900, YB-1200 (all trade names made by Central Techno Co., Ltd.) are used as fluorescent light-emitting rare earth complexes on the white card receiving layer 21 using a color inkjet head. An RGB ink including the same is created, and a latent image 105 of a color face photograph is printed (formed) on demand using the ink, and further, the name and name of the association are printed on demand using a known colored ink. Immediately after printing (forming) the visible image 103 and drying and drying for 2 seconds with a far infrared heater, a transfer substrate / release layer / hard coat layer / known as a hard coat layer transfer foil with a heat roller and a rubber roller at 145 ° C. The adhesive layer surface of the adhesive layer was superposed and transferred at a running speed of 1 m / min, and then the substrate was peeled off to obtain the recording medium 10 of Example 1.
The name of the society and the name could be observed visually, and the face photograph (latent image 105) could not be observed, but when exposed to black light, a color face photograph could also be observed.

(Example 2) In place of the hard coat layer transfer foil, except that a known hologram transfer foil composed of a transfer substrate / release layer / hologram layer / transparent reflection layer / adhesive layer was used, the same as in Example 1, A recording medium 10 of Example 2 was obtained.
The hologram reproduction image, the name of the meeting, and the name could be observed visually, and the face photograph (latent image 105) could not be observed, but a color face photograph could be observed when irradiated with black light.

It is sectional drawing of the recording medium which shows one Example of this invention. It is sectional drawing of the recording medium which shows one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Recording medium 11: Base material 13: Release layer 15: Protective layer 16: Primer layer 25: Hard coat layer 35: Hologram layer 37: Transparent reflective layer 19: Adhesive layer 21: Receptive layer 101: Transfer object 102 : Adhesion layer 103: Visible image 105: Latent image

Claims (4)

A recording medium comprising a base material and at least a receiving layer and a protective layer laminated on one surface of the base material, wherein the receiving layer includes at least a cationic urethane resin, a cationic fixing agent, and a filler. A recording medium, wherein a latent image is formed by an inkjet method using an ink containing a fluorescent light-emitting rare earth complex in the receiving layer. 2. The recording medium according to claim 1, wherein an information printing layer is formed on the receiving layer by an ink jet method in addition to the latent image. The recording medium according to claim 1, wherein the latent image is a color image. 4. The recording medium according to claim 1, wherein a hard coat layer or a hologram layer and a transparent reflective layer are used instead of the protective layer.

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