JP2008221659A - Laminate for forgery prevention - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate for forgery prevention which is aimed at preventing forgery of a commodity or a product. <P>SOLUTION: The laminate for preventing forgery of the commodity or the product is prepared by stacking sequentially a surface protective layer (1) and a colored ink layer (2) which gives a laser-colored print such a hue as not being visually recognized. The laminate thus prepared is irradiated with laser so as to color and print a character or a figure. The dimensions of the character or the figure obtained by the laser irradiation are 0.5 mm long and 0.5 mm wide, in the length and 0.5mm or less in the width. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a forgery-preventing laminate in which characters, graphics and the like for the purpose of preventing forgery are marked by laser irradiation.

  The PL Act (Product Liability Act) has been implemented, and various types of printing are required for packaging, labels, and the like. Also, the importance of display is increasing from the viewpoint of security or traceability. In particular, as overseas production and export of products increase, cheap counterfeits and counterfeit products that cannot be immediately distinguished from the appearance increase, which not only reduces profits for manufacturers but also decreases the reliability of the brand. It has become a big problem.

  The field involves a wide variety of products, such as pharmaceuticals, electronic devices, electronic parts, daily necessities, and packaging products. In order to prevent counterfeiting, the production location, distribution channel, product characteristics, etc. of the product are expressed with unique characters and figures, the display is embedded in the product itself, and information is affixed with labels and stickers. Yes.

  Conventionally, display of characters and graphics on packaging materials, labels, caps, films, containers, etc. has been performed by plate systems such as gravure printing method, flexographic printing method, offset printing method and silk screen printing method. Also, stamp printing, ink jet printing, thermal transfer ribbon method, engraving printing, and the like are performed.

However, since the anti-counterfeit printing by these printing methods is based on the conventional method, anti-counterfeiting prevention, identification symbols, numbers, characters, and figures themselves are imitated and are not a fundamental solution. Therefore, if the amount of information is increased or complicated, expensive plates and devices are required, leading to an increase in cost.

  In recent years, a forgery prevention method using a laser has been proposed as a printing method different from the conventional method. For example, according to Japanese Patent Laid-Open No. 2006-26939 (Patent Document 1), a method is proposed in which an aluminum foil or a metal vapor-deposited film is melted with a laser, and a black background is printed. Since this method uses a metal foil and a metal vapor-deposited film as essential elements, its use is limited. Japanese Patent Application Laid-Open No. 2004-262015 (Patent Document 2) proposes a method of changing the laser wavelength to produce a color pattern of a plurality of colors, but the apparatus becomes large and causes problems such as cost.

Japanese Patent Laid-Open No. 2002-321476 (Patent Document 3) discloses a method of marking small letters and small figures. However, since the background is mainly bright colors such as white, light blue, and yellow, small letters, The existence of the small figure itself is recognized, and it is necessary to make a part of the appearance of the product a bright hue, and there is a problem of restrictions on the product image and cosmetics.
JP-A-2006-26939 JP-A-2004-262015 JP2002-321476

  Then, an object of this invention is to provide the forgery prevention laminated body which gave the marking which can prevent forgery by laser irradiation, without impairing the external appearance of a product, goods, etc.

  In other words, the present invention irradiates a laser beam on a laminate in which at least a surface protective layer (1) and a colored ink layer (2) having a hue such that printing by laser color development cannot be visually recognized are sequentially laminated on a substrate. The present invention also relates to a forgery-preventing laminate in which characters and figures are color-printed.

  The present invention relates to the forgery-preventing laminate, wherein printing by laser coloring is performed in the colored ink layer (2).

  The forgery-preventing laminate according to the above, wherein printing by laser coloring is performed in a colored ink layer (3) provided on the substrate side of the colored ink layer (2) according to claim 1. .

The present invention relates to the forgery-preventing laminate, wherein the size of characters and figures obtained by laser irradiation is 0.5 mm in length and 0.5 mm or less in width.
The present invention relates to the anti-counterfeit laminate described above, wherein the substrate is paper, metal foil, or plastic film.
The forgery-preventing laminate as described above, wherein the light source for laser irradiation is any one of carbon dioxide, YAG laser, and YVO ₄ laser.

  The anti-counterfeit laminate of this embodiment has a surface protective layer, and by marking characters and figures directly inside the laminate by laser light irradiation, it becomes difficult for a third party to add or tamper with anti-counterfeiting. Is expressed. Furthermore, the anti-counterfeiting property can also be improved by changing the visibility and recognizability according to the hue difference, contrast, etc. between the laser coloring portion and the appearance. Further, since the laminate has a surface protective layer, it has excellent water resistance, oil resistance, and abrasion resistance without post-processing after laser printing.

  When the laminate is used as a package or label and characters, figures, and codes are recorded, it is possible to sufficiently exhibit discrimination for preventing counterfeiting in merchandise and product distribution management and sales expansion.

  The laminate of the present invention has, as its basic structure, a structure in which at least a surface protective layer (1) and a colored ink layer (2) having a hue such that printing by laser coloring cannot be visually recognized are sequentially laminated. ing. Examples of the surface protective layer include a plastic film, OP varnish, and radiation curing varnish. Specific configurations of the laminate are, for example, A) plastic film / anchor coat layer / colored ink layer (2) / plastic film, B) plastic film / colored ink layer (2) / paper, C) OP varnish layer / colored Ink layer (2) / plastic film. In the case of a bag that uses a laminate as a package and has a plastic film as a main component, it is preferable that the printed configuration has at least a heat-sealable film.

  The anti-counterfeiting property of the laminate for anti-counterfeit of this aspect is based on the fact that the marking can not be changed later by printing directly inside the laminate. Furthermore, the function of preventing counterfeiting is exhibited even if the third party cannot recognize the presence or contents of the marked character, the size of the graphic itself, and the balance between the printed portion and the background color.

  More specifically, when the appearance is red, indigo, brown, black, gray, etc., it is difficult to recognize even a large print. When the appearance color of a product, a product, a packaging film, a packaging box, or the like for the purpose of preventing counterfeiting is as described above, it is possible to mark hidden characters and figures without changing the color. Furthermore, if it is made small letters and small figures, it will hardly be recognized visually. In the case of actual anti-counterfeit printing, the hue at the location where marking is to be performed is a hue determined in the design of the product or product, and if necessary, adjust the hue so that it is the same or equivalent to that color. If it is colored, it is possible to give a marking for preventing counterfeiting without substantially changing the hue of the appearance. In this case, the color is adjusted in total including the hue of the laser color former.

  The laser color development is a color ink layer (2) having a hue such that the laser color printing cannot be visually recognized, or a color ink layer (2) having a hue such that the laser color printing cannot be visually observed. Is possible with another colored ink layer (3). Laser color development is performed by a laser color former that develops color with a laser. When the colored ink layer (3) is present and has laser colorability, the hue of the colored ink layer (3) does not affect the appearance of products and products derived from the hue of the colored ink layer (2). As long as it is different from the hue of the colored ink layer (2).

  For example, D) plastic film / anchor coat layer / colored ink layer (2) / colored ink layer (3) / plastic film, E) plastic film / colored ink layer (2) / colored ink layer (3) / paper, F) OP varnish layer / colored ink layer (2) / colored ink layer (3) / plastic film.

  In the forgery-preventing laminate of this embodiment, preferably the colored ink layer (3) has a laser coloring property, and the surface protective layer (1) / colored ink layer having a hue such that printing by laser coloring cannot be visually recognized. (2) / Colored ink layer (3) is preferred because it is more difficult to recognize than printing.

  Examples of the material having laser colorability include inorganic materials and organic materials. The inorganic material used in this embodiment is, for example, 1) a simple metal, 2) a metal salt, 3) a metal hydroxide, 4) a metal oxide, or the like.

  1) Examples of simple metals include iron, zinc, tin, nickel, copper, silver, and gold.

  2) Metal salts include copper carbonate, nickel carbonate, manganese carbonate, cobalt carbonate, lanthanum carbonate, magnesium nitrate, manganese nitrate, iron nitrate, cadmium nitrate, zinc nitrate, cobalt nitrate, lead nitrate, nickel nitrate, copper nitrate, Palladium nitrate, lanthanum nitrate, magnesium acetate, manganese acetate, cadmium acetate, zinc acetate, cobalt acetate, lead acetate, nickel acetate, copper acetate, palladium acetate, copper chloride, iron chloride, cobalt chloride, nickel chloride, silver chloride, zinc chloride , Copper phosphate, iron phosphate, cobalt phosphate, copper pyrophosphate, copper sulfate, iron sulfate, cobalt sulfate, copper oxalate, iron oxalate, cobalt oxalate, copper benzoate, iron benzoate, cobalt benzoate, Examples thereof include copper phosphonate having an aromatic ring.

  3) Examples of the metal hydroxide include copper hydroxide, aluminum hydroxide, magnesium hydroxide, zinc hydroxide, antimony hydroxide, cobalt hydroxide, nickel hydroxide, iron hydroxide, and lanthanum hydroxide.

  4) Examples of metal oxides include silicon oxide, aluminum oxide, iron oxide, magnesium oxide, cobalt oxide, lead oxide, tin oxide, indium oxide, manganese oxide, molybdenum oxide, nickel oxide, copper oxide, palladium oxide, and lanthanum oxide. , Antimony-doped tin oxide (ATO), indium-doped tin oxide (ITO), synthetic zeolite, natural zeolite, copper-molybten complex oxide (42-903A, manufactured by Toago Material Technology Co., Ltd.), and the like. As the metal oxide, mica, montmorillonite, smectite, etc. having a layered structure can also be used.

  Among inorganic materials, one or more materials selected from copper compounds, molybdenum compounds, iron compounds, nickel compounds, chromium compounds, zirconium compounds, or antimony compounds, more preferably copper compounds, molybdenum compounds, chromium compounds, nickel A material having a compound, more preferably, a copper-molybdenum composite oxide or the like can be given. In particular, the copper-molybten complex oxide has strong self-coloring properties, and the resin in the vicinity of the copper-molybdenum complex oxide itself can be easily blackened, so that a printed matter with excellent visibility can be obtained.

  Even when irradiated with a laser, the inorganic material itself does not develop color, and the nearby binder resin, additive, and the like may carbonize, decompose, and vaporize to develop color.

  A dye can also be used as an organic material having laser colorability. Although there is no restriction | limiting in particular as dye, It can select suitably according to the intended purpose, use, and use environment of a recording material. A print with high visibility can be obtained by using, as the dye, a known color former or developer used in ordinary thermal recording.

  For example, as the color former, a color developable compound used as an electron donor in ordinary thermal recording can be used. For example, leuco dyes such as fluorane, phenothiazine, spiropyran, triphenylmethphthalide, rhodamine lactam and the like can be mentioned. Specific examples of the leuco dye include 3,3-bis (p-dimethylaminophenyl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, and 3,3-bis (p- Dimethylaminophenyl) -6-aminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-nitrophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3,3-bis (3-dimethylamino) ) -7-methylfluorane, 3-diethylamino-7-chlorofuran, 3-diethylamino-6-chloro-7-methylfluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-6-methyl- Examples include 7-anilinofluorane and 3-piperidino-6-methyl-7-anilinofluorane.

  The developer is usually used together with a color former.

  As the developer, a substance used as an electron acceptor in a heat-sensitive recording material, such as 4-phenylphenol, 4-hydroxyacetophenone, 2,2-dihydroxydiphenyl, 2,2-methylenebis (4- Chlorophenol), 2,2-methylenebis (4-methyl-6-tert-butylphenol), 4,4-isopropylidenediphenol, 4,4-isopropylidenebis (2-chlorophenol), 4,4-isopropylidene Bis (2-methylphenol), 4,4-ethylenebis (2-methylphenol), and other acidic clay kaolin, zeolite, aromatic carboxylic acid, its anhydride, and organic sulfonic acid can be used. Of these, phenol compounds are preferred.

  The ratio of the color former to the developer is preferably 2 to 10 parts by weight with respect to 1 part by weight of the color developer.

  A leuco dye is preferably used because it has good color developability by laser heat. In this embodiment, particularly when a dye is used, it is preferable that there is no boil or retort in the manufacturing process of the product because the dye may be eluted even if the recording material has a surface protective layer.

  The total amount of laser color formers in the colored ink layer (2) or colored ink layer (3) is 0.1 to 90.0 in 100 parts by weight of the colored ink layer (2) or colored ink layer (3). If it is contained in parts by weight, it is preferable from the viewpoint of the balance between the film strength, the cohesive force and the color developability of the colored ink layer (2) or the colored ink layer (3). Most preferably, it is 5.0-60.0 weight part.

  If it is less than 0.1 part by weight, the color developability is inferior although there is cohesion as a film. On the other hand, when the amount exceeds 90 parts by weight, the strength and cohesive strength of the film are lowered, the bending resistance of the recording material laminated by laser irradiation is lowered, and in some cases, the layers are peeled off.

  Next, as the binder resin constituting the colored ink layer (2) or the colored ink layer (3), acrylic resin, acrylic modified urethane resin, styrene / acrylic resin, ethylene / acrylic resin, urethane resin, polyester resin, rosin modified Cellulose resins such as maleic acid resin, vinyl chloride / vinyl acetate copolymer, polyvinyl acetal resin, polyamide resin, hydroxyethyl cellulose, hydroxypropyl cellulose, nitrocellulose and the like can be mentioned. These resins can be obtained singly or by mixing two or more.

  Among these resins, urethane resins are particularly suitable as recording materials because they have particularly good adhesion to films and are excellent in thermal relaxation properties. Cellulosic resins, particularly nitrocellulose resins, have good color developability by laser, and improve color developability as a colored ink layer even if laser absorbability of a color former or the like is poor.

  Moreover, a photocurable resin etc. can also be used as binder resin. Specifically, unsaturated polyester resins, acrylate resins, polyene / polythiol resins, spirane resins, epoxy resins, amino alkyd resins, diallyl phthalate resins, unsaturated polyester resins, furan resins, etc. Can be mentioned. These resins and various monomers such as ultraviolet curable monomers, prepolymers, and photopolymerization initiators are used as necessary.

  The content of the binder resin in the colored ink layer (2) or the colored ink layer (3) is 10.0 to 99.9 weight in 100 parts by weight of the colored ink layer (2) or colored ink layer (3). It is preferable in terms of the cohesive strength of the film and the adhesion to the substrate. If the amount is less than 10.0 parts by weight, the resin content is small, so that the adhesion of the film to the substrate and the cohesive force of the film are inferior, leading to a decrease in bending resistance and stability over time as a recording material. On the other hand, if it exceeds 99.9 parts by weight, the laser coloring property is inferior.

  Examples of the additives include pigment dispersants, antifoaming agents, leveling agents, waxes, silane coupling agents, preservatives, rust inhibitors, plasticizers, flame retardants, and color developers.

  These additives are used particularly for the purpose of improving the printability, printing effect, etc. of the colored ink layer (2) or the colored ink layer (3). It can be appropriately selected depending on conditions.

  In the laminate of this embodiment, the colored ink layer (2) or the laser coloring layer formed from the colored ink layer (3) is sandwiched between the surface protective layer and the substrate. Due to the presence of these, it is possible to prevent peeling, scattering, abrasion, and the like of the printed surface during printing and during use.

  In addition, the feature of the laminate of this embodiment is that a surface protective layer (1) and a colored ink layer (2) having a hue such that laser-colored printing cannot be visually recognized are essential as constituent elements of the laminate. It is. The surface protective layer mentioned here is a layer present at the uppermost portion in the direction visually recognized in the usage pattern, and is not directly related to the stacking, printing, and coating order of the laminate. The method for providing the surface protective layer and the laser color-forming printing ink layer on the substrate is not particularly limited, and when both are liquid, methods such as ink jet, dipping, spin coating, and printing can be used. In this embodiment, a method of laminating by printing is preferable. When the surface protective layer is a film, it is printed and coated as a base material, or in some cases, it becomes a constituent element of a laminate by bonding.

  The colored ink layer (2) or the colored ink layer (3) is formed through a process such as solvent drying and radiation curing after printing the colored ink. Such a colored ink can be adjusted as, for example, gravure printing ink, offset printing ink, flexographic printing ink, silk screen printing ink, and the like.

  Next, an example of a manufacturing process of a laminate having at least a surface protective layer (1) and a colored ink layer (2) having a hue such that printing by laser coloring cannot be visually recognized will be described.

a) Adjustment of the colored ink layer (2) The general adjustment of the colored ink is a liquid solvent composed of an organic solvent, water, etc. using a pigment, a laser color former when a laser color developability is required, a dispersant, a resin, etc. It is preferable to be dispersed. The resin and dispersant used must be suitable for dispersing pigments and the like. When the laser color former is added, the amount used is preferably 1 to 60% by weight based on the total amount of the final printing ink after the addition. More preferably, it is 2 to 50% by weight. If the content of the laser color former exceeds 60% by weight, poor dispersion tends to occur, and the recording characteristics of the laminate may be impaired. When it is less than 1% by weight, the color developability is greatly reduced.

  In the case of imparting pigments and laser color developability, a paint conditioner (manufactured by Red Devil Co., Ltd.) is used as a disperser used when preparing a coating liquid by further dispersing a laser color former in a liquid medium such as an organic solvent or water. ), Ball mill, sand mill (such as “Dyno mill” manufactured by Shinmaru Enterprises), attritor, pearl mill (such as “DCP mill” manufactured by Eirich), coball mill, homomixer, homogenizer (“CLEAMIX” manufactured by M Technique), etc. ), Wet jet mills (“Genus PY” manufactured by Genus, “Nanomizer” manufactured by Nanomizer), and the like. When using media in the disperser, it is preferable to use glass beads, zirconia beads, alumina beads, magnetic beads, styrene beads, or the like.

  As the organic solvent, known solvents used for printing can be used, and examples thereof include ethanol, isopropyl alcohol, methyl acetate, methyl isobutyl ketone, 1-methoxy-2-propanol, toluene, xylene and the like.

The colored ink layer (2) needs to have a hue such that printing by laser coloring cannot be visually recognized. Preferably, inks having various hues necessary for toning are prepared in advance and matched with the target hue. In this case, the laser color former may be contained in the ink having any hue. Alternatively, it is also possible to adjust the dispersion with the laser color former alone and to mix them together at the time of toning.
The same applies to the colored ink layer (3). However, since the colored ink layer may be different from the hue of the appearance of the product or product, it may be a liquid dispersion of the laser color former itself.

b) Printing on a base material composed of film, paper, etc. Examples of the base material used in this embodiment include plastic film, paper, and metal foil. Plastic films include low-density polyethylene, unstretched and stretched polypropylene, polyester, nylon, polystyrene, polyvinyl chloride, polycarbonate, polyvinyl alcohol film, and films such as polypropylene, polyester, nylon, and cellophane coated with polyvinylidene chloride. Can be mentioned. A vapor deposition film, for example, a PET film on which silica or the like is vapor-deposited can also be used. As paper, art paper, coated paper, fine paper, Japanese paper, synthetic paper, etc., as metal foil, foil made of metal such as copper, aluminum, nickel, iron, gold, silver, stainless steel, tungsten, chromium, titanium, or A foil made of an alloy obtained by combining two or more of them can be used. Copper, aluminum, and nickel foils are suitable from the viewpoint of price, but aluminum foil is generally used as a packaging material. A metal foil having a thickness suitable for printing can be used. Moreover, when a release paper is used as a substrate and a pressure-sensitive adhesive layer is further provided, the laminate of the present invention can also be used as a label.

The thickness of the substrate is not particularly limited. In the case of a plastic film, the film normally used for printing can be applied as it is. For example, in the case of PET, 12 to 40 μm and in the case of OPP, 20 to 50 μm are preferably used.
In the production of the anti-counterfeit laminate, in addition to the single color printing of the colored ink that forms the colored ink layer (2) having a hue such that the laser-colored printing cannot be visually recognized, the colored ink layer (3) is further colored. It is possible to overprint ink.

  In the latter case, laser irradiation is performed through the colored ink layer (2), and printing is sufficiently possible by controlling the laser irradiation conditions and the thickness of the colored ink layer (2). The thickness of the colored ink layer (2) is preferably 0.1 to 3 μm / layer. When the substrate is also transparent, laser irradiation can be performed not from the surface protective layer side but from the substrate side.

c) Formation of surface protective layer The surface protective layer is formed of a plastic film and OP varnish. About the plastic film, the same film as that used in the above-described printing and coating, for example, can be used. The OP varnish layer is roughly classified into 1) a method of applying and drying a coating solution and 2) a method of printing, applying and drying, and a method of forming by radiation irradiation curing.

  The thickness of the OP varnish layer is not particularly limited, but is preferably 1 μm or more in the method of forming from the coating liquid. When the laser is irradiated with a thin thickness, depending on the laser wavelength and the type of OP varnish layer, the surface is damaged by the heat accompanying the laser irradiation, the inside of the coating layer is exposed, and the printability as a laminate, solvent resistance, Wear resistance and the like are reduced.

  When the OP varnish layer is formed from a coating liquid, as a binder resin of the coating liquid, for example, water-soluble cellulose, methyl cellulose, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyacrylamide, polyacrylic acid, casein, Gelatin, styrene / maleic anhydride copolymer salt, isobutylene / maleic anhydride copolymer salt, polyacrylic acid ester, polyurethane resin, acrylic / styrene resin and the like can be mentioned. Solvent type resins include styrene / maleic acid, acrylic / styrene resin, polystyrene, polyester, polycarbonate, epoxy resin, polyurethane resin, polybutyral resin, polyacrylate ester, styrene / butadiene copolymer, styrene / butadiene / acrylic acid copolymer Examples include polymers and polyvinyl acetate. In the coating liquid, a curing agent can be used in combination for the purpose of improving the film strength, heat resistance, water resistance, solvent resistance and the like of the OP varnish layer. As the curing agent, isocyanate, oxazoline, carbodiimide, ethyleneimine, and the like can be used. From the viewpoint of film strength and film physical properties, isocyanate-based curing agents are preferred. Of the isocyanate curing agents, those having 3 or more functional groups are particularly good.

  Further, when a radiation curable layer is provided as the OP varnish layer, a monomer having one or more ethylenically unsaturated bonds, a prepolymer oligomer, or the like is used. Examples of monomers that can be used in the present invention include N-vinylpyrrolidone, acrylonitrile, styrene, acrylamide, 2-ethylhexyl acrylate, 2-hydroxy (meth) acrylate, 2-hydroxypropyl (meth) acrylate, tetrahydrofurfuryl acrylate, and phenoxyethyl. Acrylate, nonylphenoxyethyl acrylate, butoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, cyclohexyl (meth) acrylate, N, N-dimethylamino (meth) acrylate, N, N-dimethylaminoethyl (meth) Monofunctional monomers such as ethyl acrylate, 3-phenoxypropyl acrylate, 2-methoxyethyl (meth) acrylate, ethylene glycol diacrylate Diethylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecane Bifunctional monomers such as diol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethyloloctane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, etc. Tetrafunctional monomers such as trifunctional monomers, pentaerythritol polypropoxytetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate Other 5 dipentaerythritol penta (meth) acrylate as a functional or more monomers, dipentaerythritol hexa (meth) acrylate. When monomers, prepolymers, and oligomers are used as the radiation curable composition, it is preferable to use trifunctional or higher functional monomers, prepolymers, and oligomers within 20 to 95% by weight. If it is 20% by weight or less, the film density and film strength of the OP varnish layer are low, and in some cases, the smoothness of the printed surface is lowered, and physical properties such as water resistance, oil resistance, and wear resistance are also lowered. When the amount is 95% by weight or more, the OP varnish layer becomes too hard, and when the printed matter is bent, the OP varnish layer is easily peeled off.

  The radiation curable OP varnish requires a photopolymerization initiator and, if necessary, a sensitizer when cured with ultraviolet rays. As photopolymerization initiators, acetophenone series, benzophenone series, thioxanthone series, benzoin series, benzoin methyl ether series, etc. As sensitizers, N-methyldiethanolamine, diethanolamine, triethanolamine, P-dimethylaminobenzoic acid isoamyl ester, etc. Amine compounds, tri-n-butylphosphine, Michler's ketone and the like can be used. In the case of electron beam curing, curing can be performed without using the above-mentioned photopolymerization initiator, sensitizer and the like.

  In order to cure the radiation curable OP varnish, 1) Ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc lamp, metal halide lamp, etc. are used as ultraviolet irradiation. 2) For electron beam irradiation, various electron beam accelerators such as Cockloft Walton, Bandegraft, resonant transformer, insulated core transformer, linear type, dynamitron type, high frequency type, etc. Irradiate electrons with energy of 1000 eV.

  In the coating liquid used as the OP varnish layer, additives such as an antifoaming agent, an ultraviolet absorber, a lubricant, an antistatic agent, and a curing agent, and coating properties as necessary for improving coating properties and film properties. Solvents such as isopropyl alcohol, methyl isobutyl ketone, 1-methoxy-2-propanol, and toluene can be used for the purpose of improving printability.

  In this way, identification markings for the purpose of preventing forgery are applied to a part or the entire surface of the obtained laminate having anti-counterfeit properties. Since the laser color former layer is present inside the laminate, it is possible to eliminate the peeling and scratching of prints, which has been a problem with conventional prints, and to eliminate blurring caused by contact with oil and moisture. You can also.

  In addition to displaying the desired contents in alphanumeric characters, hiragana, kanji, etc., laser printing can write a larger amount of various information as a barcode or a two-dimensional barcode. As the two-dimensional code, there are QR (model 1), QR (model 2), micro QR, DataMatrix, and the like. It is also possible to draw and draw photos and figures through a personal computer.

Next, the recording method of this aspect will be described. Examples of the laser that can be suitably used in this embodiment include a carbon dioxide laser (10640 nm), a YAG laser (1064 nm), and a YVO ₄ laser (1064 nm). A YAG laser and a YVO ₄ laser are preferable. More preferably, it is a YVO ₄ laser, and since the intensity distribution of the laser light is a single mode power distribution, finer printing is possible.

Irradiation with YAG laser or YVO ₄ laser can control print quality by 1) LD%, 2) Q-switch frequency, and 3) scanning speed.

  LD% represents the laser output. The laser power can be controlled by LD%, but if it is too large, the surface protective layer is easily damaged. If it is too small, the print becomes unclear.

The Q-switch frequency represents the frequency at which pulses are generated. The Q-switch frequency also affects the print quality, and if it is too large or too small, the printability is degraded.
The scanning speed controls the interval between printing dots, printing time, and the like. If the scanning speed is too slow, the printing dots are concentrated, and in some cases, the laser coloring layer is damaged. On the other hand, if it is too early, the space between the print dots becomes wide, and in some cases, the print density and the print quality are lowered.
For the purpose of preventing counterfeiting, it is possible to reduce the size of characters and figures so that only the parties can recognize them. In the case of a character, for example, if the length and width of the character are 0.5 mm or less, it is difficult to recognize the presence of the character even if the contrast between the appearance of the product and the product is insufficient, and it has anti-counterfeiting properties. Each is preferably 0.3 mm or less, and more preferably 0.2 mm or less.

  The laminate of the present invention is also useful for labels, and can be used for bar code labels, product display labels, etc., or luggage tags, patches, seals, stickers, etc. having similar functions.

  The basic structure of the label is a surface protective layer (1), a colored ink layer (2) / adhesive layer / release paper having a hue such that printing by laser coloring cannot be visually recognized, and the laminate of the present invention is applied. Is done. The pressure-sensitive adhesive layer is formed of a coating film obtained by applying and drying a coating liquid such as an acrylic resin or a polyester resin using natural rubber, synthetic rubber, polyisobutylene, 2-ethylhexyl acrylate / n-butyl acrylate, or the like. If necessary, a tackifier such as abietic acid rosin ester, a terpene / phenol copolymer, an isocyanate-based, and an epoxy-based curing agent can be used in the coating solution.

As the release paper, a release paper obtained by applying a silicone-based or fluorine-based release agent to a paper base, a laminated paper coated with a polyolefin resin, or the like can be used.
Laser irradiation can be performed before or after affixing to a target label.

  The present invention is intended to prevent counterfeiting, but it can also be used for the purpose of parties to give unique identification numbers, symbols, characters, figures, etc. in order to respond to investigations of product and merchandise distribution status, claims, etc. it can. In this case, normal printing and marking impair the appearance, appearance, and design of products and products, so that the presence of characters and figures can be made inconspicuous.

Hereinafter, this embodiment will be described in more detail based on examples. In the examples, parts represent parts by weight.
(Synthesis Example 1) Synthesis of Urethane Resin Polytetramethylene glycol (molecular weight 2000, molecular weight was measured by gel permeation chromatography in a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube. 1000 parts) and 222 parts of isophorone diisocyanate were charged and reacted at 85 ° C. for 5 hours in a nitrogen atmosphere. Next, after cooling to 40 ° C., 82 parts of isophorone diamine, 7.8 parts of di-n-butylamine, 1244 parts of toluene, 1244 parts of methyl ethyl ketone and 573 parts of isopropyl alcohol were added and reacted at 40 ° C. for 5 hours with stirring. The urethane resin thus obtained had a solid content of 30% and a viscosity of 350 cps (25 ° C.).
(Synthesis Example 2) 130 parts of phenylphosphonic acid was dissolved in 1350 parts of synthetic water of copper phenylphosphonate. To this, 103 parts of copper sulfate pentahydrate was added and stirred at room temperature for 2 hours. The precipitate was filtered, washed with water, and dried under reduced pressure at 100 ° C. to obtain 35 parts of copper phenylphosphonate.
(Adjustment of indigo ink)
Paint mixture of 120 parts of LIONOL BLUEFG7350 (manufactured by Toyo Ink Manufacturing Co., Ltd.) as an indigo pigment, 300 parts of urethane resin obtained in Synthesis Example 1, 1 part of antifoaming agent Dehydran 1620 (manufactured by Cognis), and 100 parts of methyl ethyl ketone. Kneaded to obtain indigo ink.

(Red ink adjustment)
As a red pigment, a paint shaker was prepared by mixing 120 parts of LIONOL RED FG3303 (manufactured by Toyo Ink Manufacturing Co., Ltd.), 300 parts of urethane resin obtained in Synthesis Example 1, 1 part of antifoaming dehydran 1620 (manufactured by Cognis), and 100 parts of methyl ethyl ketone. And kneaded to obtain red ink.

(Black ink)
As a black pigment, 100 parts of Printex V (manufactured by Degussa), 300 parts of the urethane resin obtained in Synthesis Example 1, 1 part of defoaming agent Dehydran 1620 (manufactured by Cognis), and 100 parts of methyl ethyl ketone are kneaded with a paint shaker. , Got ink ink.
(Adjustment of laser marking ink A)
A laser marking ink A was obtained by kneading a mixture of 20 parts of copper phenylphosphonate as a laser color former, 100 parts of the urethane resin obtained in Synthesis Example 1 and 50 parts of methyl ethyl ketone with a paint shaker.
(Adjustment of laser marking ink B)
As a laser color former, a mixture of ATO-coated mica, 20 parts of laser flare 820 (manufactured by Merck), 100 parts of urethane resin obtained in Synthesis Example 1 and 50 parts of methyl ethyl ketone was kneaded with a paint shaker to obtain laser marking ink B. .
(Example 1)
79.5 parts of indigo ink, 0.5 part of black ink, and 20 parts of laser marking ink A are mixed to obtain a laser marking ink that forms a colored ink layer (2) having a hue such that printing by laser coloring cannot be visually recognized. It was. The obtained printing ink was further diluted with a mixed solvent of methyl ethyl ketone, ethyl acetate and isopropyl alcohol (weight ratio 50:40:10), and adjusted to 17 seconds (25 ° C.) with Zahn Carp # 3 (manufactured by Ransha Co., Ltd.) A diluted laser marking ink forming a colored ink layer (2) was obtained.

Using a gravure plate having a plate depth of 35 μm as a substrate, printing was performed at a printing speed of 50 m / min and a drying temperature of 60 ° C. to obtain a printed matter having a colored ink (2). Low density polyethylene “TUX-FCD” (manufactured by Tosello, film thickness 40 μm) is bonded to the obtained printed matter with a heat roller, and finally the surface protective layer / coloring with a hue that makes it impossible to visually recognize the printed color by laser coloring. A laminate having an ink layer (2) was obtained.
(Examples 2 to 5, Comparative Example 1)
Table 1 shows the composition of the inks forming the colored ink layer (2) and the colored ink layer (3) used in Examples 2 to 5 and Comparative Example 1. The blended ink forming each layer was diluted with a mixed solvent of methyl ethyl ketone, ethyl acetate and isopropyl alcohol (weight ratio 50:40:10), and adjusted to 17 seconds (25 ° C.) with Zahn Carp # 3 (manufactured by Hosei Co., Ltd.). . The bonding of PE was performed in the same manner as in Example 1.

About the obtained layered product in Example 1-5, and Comparative Example 1, using a YVO ₄ laser, "Keyence MD-9600", the printing by laser was carried out in the size of the character described in Table 1. The printing conditions are a scanning speed of 500 mm / s, a laser power of 15%, and a Q-SW frequency of 20 kHz.
The laminate for which laser printing was performed was evaluated for anti-counterfeiting properties. The anti-counterfeiting was evaluated by 1) whether the printed place can be visually recognized (visually) or 2) whether the printed contents can be identified (enlarged). Each test method will be described below.

Visibility test of printed location: Visual observation The printed laminate was directly observed under daylight, and the visibility was evaluated in three stages. The results are shown in Table 2. In addition, the direction which cannot be visually recognized is preferable for anti-counterfeiting.

○: Not visible △: A little visible
X: Easily visually recognized Identification test of printed contents: Enlarged The printed laminate was observed with a 30-fold magnifier, and the identification of the contents was evaluated in three stages. The results are shown in Table 2. It should be noted that it is preferable that the print contents cannot be identified at a magnification of about 30 times.

○: Cannot be identified △: Very poor identification
×: Unrecognizable comprehensive evaluation of anti-counterfeiting ○: Excellent anti-counterfeiting △: Slightly inferior anti-counterfeiting
×: Anti-counterfeiting is difficult

Claims (6)

A laser beam is applied to a laminate in which at least a surface protective layer (1) and a colored ink layer (2) having a hue such that printing by laser coloring cannot be visually recognized on a base material, and characters and figures are colored. Printed anti-counterfeit laminate.   2. The counterfeit-preventing laminate according to claim 1, wherein printing by laser coloring is performed in the colored ink layer (2).   The anti-counterfeiting laminate according to claim 1, wherein printing by laser coloring is performed in a colored ink layer (3) provided on the substrate side of the colored ink layer (2) according to claim 1. body.   The forgery-preventing laminate according to any one of claims 1 to 3, wherein the size of characters and figures obtained by laser irradiation is 0.5 mm in length and 0.5 mm or less in width. 5. The counterfeit-preventing laminate according to claim 1, wherein the substrate is paper, metal foil, or plastic film. The laminate for anti-counterfeiting according to any one of claims 1 to 5, wherein a light source for laser irradiation is any one of carbon dioxide, YAG laser, and YVO ₄ laser.