JP2006056019A - Thermal recording medium, thermal recording medium label, thermal recording medium transfer sheet and information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal recording medium with a means for genuineness judgment to a thermal recording layer for visual information recording and also an information recording medium which is of a suited application shape for an objective article and constituted jointly of the thermal recording medium and another information recording means. <P>SOLUTION: In this information recording medium 9, the thermal recording medium 1 formed of a color changing layer, e.g. a laminate of an optical selective reflection layer 2 and the thermal recording medium 3, is applied to a base material 10 with a magnetic recording layer 11 and the like formed thereon and if necessary, a protecting layer 7 and the like are formed. The optical selective reflection layer 2 shows a changing hue depending on a viewing angle and the genuineness of the object article can be judged by stacking a right-handed circularly polarized light plate or a left-handed polarized light plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-sensitive recording medium that can be distinguished from those obtained by forgery or falsification based on illegal intentions. The present invention also relates to such a thermal recording medium processed into a label form or transfer sheet form suitable for application to a target article. Furthermore, the present invention also relates to an information recording medium to which a thermal recording medium is applied.

  Various cards such as credit cards or deposit / savings cards, transportation commuter pass tickets, or ID cards usually have information such as the name and number of each owner, validity period, or riding section according to the purpose of use. Selected and recorded as visual information. When recording information as visual information, a thermal coloring method that requires a short time for recording and does not require a large apparatus is often used. As the thermosensitive coloring method, an irreversible method is usually used, so although tampering is difficult, the visual information obtained is not so high in resolution and the color density is constant, so it is possible to try counterfeiting with a color copier, etc. There is sex.

  Conventionally, in order to prevent counterfeiting by color copiers, advanced inks such as using special inks that use dichroic dyes or forming fine tints that are visible to the naked eye but cannot be copied at the resolution of copiers, etc. Attempts have been made to use printing technology. However, when recording information by the thermal coloring method as visual information, the coloring hue is determined in advance by the material, and it is difficult to increase the resolution. Difficult to do.

As a forgery prevention card, a base material, a reflective layer, and a patterned thermotropic polymer liquid crystal layer are formed in this order, and the thermotropic polymer liquid crystal layer is heated and pressed to give liquid crystal properties, and a polarizing film A structure in which the pattern of the thermotropic polymer liquid crystal layer can be seen through the film is proposed. (Patent Document 1).
Japanese Unexamined Patent Application Publication No. 2004-122666 (Claim 1).

  The anti-counterfeit card described in Patent Document 1 has a latent image that cannot be seen with the naked eye, and the latent image is visualized through a polarizing film, and a unique color is visible. It is said that the judgment is possible. However, if a thermographic polymer liquid crystal layer having a pattern as described in Patent Document 1 is laminated adjacent to a heat-sensitive recording layer on which recording is performed by heat-sensitive color development, and then heated and pressed to finish, the heat-sensitive recording is performed. The layer may also develop color. In addition, it is possible to apply the same recording as a latent image to the thermotropic polymer liquid crystal layer when recording on the thermal recording layer, but individual information is usually recorded on the thermal recording layer. It is difficult to have a certain latent image, which is not preferable for authenticity determination.

  An object of the present invention is that when a thermal recording layer is used for recording visual information, there is no restriction when forming adjacent to the thermal recording layer, and a certain optical performance suitable for authenticity determination is obtained. It is an object of the present invention to provide a heat-sensitive recording medium provided with a means for determining authenticity. Moreover, the subject of this invention makes it a subject to provide what has a form suitable for applying to a target article as a thermal recording medium. Furthermore, an object of the present invention is to provide an information recording medium constituted by using other information recording means in addition to such a thermal recording medium.

  It has been found that the above-mentioned problems of the present invention can be solved by forming and using a heat-sensitive recording layer by laminating a light-selective reflection layer composed of cholesteric liquid crystal and other color change layers and a heat-sensitive recording layer. And based on this, the present invention was able to be reached.

  A first invention for solving the problem relates to a heat-sensitive recording medium, wherein a color-changing layer that gives a different color depending on a viewing angle and a heat-sensitive recording layer that develops color by heating are laminated.

  According to a second aspect of the present invention, in the first aspect, the color change layer is a light selective reflection layer having light selective reflectivity that reflects either left circularly polarized light or right circularly polarized light in incident light. The present invention relates to a thermosensitive recording medium.

  In a third aspect of the invention, at least one of the color change layer and the thermosensitive recording layer in the first invention, or at least one of the light selective reflection layer and the thermosensitive recording layer in the second invention is two or more. It is related with the thermosensitive recording medium characterized by comprising.

  A fourth invention relates to a thermal recording medium label, wherein an adhesive layer is laminated on a laminate in which the thermal recording medium of any of the first to third inventions and a sheet-like substrate are laminated. It is.

  The fifth invention is characterized in that the heat-sensitive recording medium side of the laminate comprising the heat-sensitive recording medium of any one of the first to third inventions and an adhesive layer is detachably laminated with a sheet-like substrate. The present invention relates to a thermal recording medium transfer sheet.

  A sixth aspect of the present invention relates to an information recording medium characterized in that an information recording means is provided on a base material, and the thermal recording medium of any one of the first to third aspects of the invention is laminated.

  A seventh invention relates to an information recording medium according to the sixth invention, wherein the information recording means is a magnetic recording layer or an IC chip.

  According to the first invention, there is no problem in formation, there is no problem in the recording on the heat-sensitive recording layer and the visibility of recorded information, and there is a change in hue depending on the viewing angle. Therefore, it is possible to provide a heat-sensitive recording medium.

  According to the second invention, in addition to the effects of the first invention, the presence of the light selective reflection layer can be confirmed by irradiating right circularly polarized light or left circularly polarized light, and a heat sensitive recording medium capable of determining authenticity. Can be provided.

  According to the third invention, in addition to the effects of the first or second invention, the color change layer or / and the thermosensitive recording layer, the light selective reflection layer or / and the thermosensitive recording layer are composed of two or more layers. Therefore, the optical characteristics of the color changing layer or the light selective reflection layer can be made more complicated, or the hue of the information portion recorded on the thermal recording layer can be two or more colors. A medium can be provided.

  According to the fourth aspect of the present invention, the adhesive article is formed by laminating the adhesive layer on the heat-sensitive recording medium that can exhibit the effects of any one of the first to third aspects of the invention. It is possible to provide a heat-sensitive recording medium label that can be easily applied to the present invention.

  According to the fifth invention, the heat-sensitive recording medium transfer sheet that can be easily applied to the target article because the heat-sensitive recording medium capable of exhibiting the effects of any one of the first to third inventions is configured to be transferable. Can be provided.

  According to the sixth invention, the heat-sensitive recording medium of any one of the first to third inventions is applied to the base material provided with the information recording means. In addition to the effect, it is possible to provide an information recording medium that can record and use information in the information recording means.

  According to the seventh invention, in addition to the effects of the sixth invention, since the information recording means is defined as a magnetic recording layer or an IC chip, an information recording medium capable of electromagnetically writing and / or reading invisible information is provided. Can be provided.

  FIG. 1 is a diagram showing a laminated structure of the thermal recording medium of the present invention, FIG. 2 is a diagram showing a form suitable for applying the thermal recording medium of the present invention to a target article, and FIG. 3 is a diagram of the present invention. It is a figure which shows the laminated structure of the information recording medium to which the thermal recording medium of no.

  As shown in FIG. 1 (a), a thermal recording medium 1 of the present invention is basically a laminate of a color change layer 2 and a thermal recording layer 3 which give different colors depending on the viewing angle. As shown in FIG. 1B, the heat-sensitive recording medium 1 may be composed of one color change layer 2 and two layers 3a and 3b as heat-sensitive recording layers. Although not shown, the thermal recording medium 1 may be composed of two color change layers and one thermal recording layer. Alternatively, as shown in FIG. 1 (c), the thermal recording medium 1 is composed of two layers, a layer 2a and a layer 2b, as a color change layer, and two layers, a layer 3a and a layer 3b, as a thermal recording layer. The color change layer and / or the thermosensitive recording layer may be composed of two or more layers. The order of stacking the color change layer and the thermal recording layer constituting the thermal recording medium 1 of the present invention may be arbitrary. When the color change layer is composed of two or more layers, the two or more layers of the same kind may be in contact with each other, or other layers may be interposed therebetween. The same applies when the heat-sensitive recording layer is composed of two or more layers.

  The color change layer 2 can be configured by using various materials, for example, by using a pigment whose color changes depending on the viewing angle, by using a vapor deposition thin film, or by using a dichroic dye. . Examples of pigments whose color changes depending on the viewing angle include pearl pigments in which layers of high refractive index silicon oxide, titanium oxide, iron oxide, and the like, and layers of low refractive index mica, etc. are laminated. Are available from Shiseido Co., Ltd. under the trade name; Infinite Color and Merck (Germany) trade name; Iriodin. The deposited thin film is formed by forming a metal such as aluminum or other material as a thin film by a vapor phase method, and exhibits a so-called interference color like an oil thin film floating on the water surface. A dichroic dye is composed of long-chain dye molecules that have different light absorption depending on the direction of the molecular axis. For example, the light component in the normal direction relative to the direction of the molecular axis of the dye molecule has almost no absorption. The light component in the direction parallel to the direction of the molecular axis has an absorptive property and does not transmit light, and examples include anthraquinone, azo, or bisazo dyes. can do. Among the above, pigments or dichroic dyes that change color depending on the viewing angle are dispersed in an appropriate binder resin, diluted with a solvent to form a coating composition, silk screen printing, gravure printing, or a known one What is necessary is just to apply to a target surface by the coating method.

  The color change layer 2 constituting the thermosensitive recording medium 1 can also be constituted using cholesteric liquid crystal. The cholesteric liquid crystal layer in the aligned state has a property of reflecting only one of left circularly polarized light and right circularly polarized light in incident light. Also, it has an effect that the hue looks different depending on the viewing angle. The light selective reflection layer 2 can be formed by applying a solvent solution of a cholesteric liquid crystal by various printing methods and drying it. Alternatively, at this time, an ultraviolet polymerizable composition is formed using a polymerizable cholesteric liquid crystal. The ultraviolet polymerizable composition prepared and obtained can be applied by various printing methods, and after drying, it can be polymerized by irradiation with ultraviolet rays. The light selective reflection layer 2 made of a cholesteric liquid crystal layer has transparency, except that the hue looks different depending on the viewing angle, and is transparent in that sense.

  In order to realize the alignment state, an ultraviolet polymerizable composition prepared using a solvent solution of cholesteric liquid crystal or polymerizable cholesteric liquid crystal is applied to the surface of the stretched plastic sheet, or an alignment film is formed on the surface of the object. After the formation, an ultraviolet polymerizable composition prepared by using a cholesteric liquid crystal solvent solution or a polymerizable cholesteric liquid crystal may be applied. When two or more light selective reflection layers 2 are provided, the thickness of the layers, the helical pitch of the material, and the like can be made different so that more complicated optical characteristics can be given. Alternatively, since the light selective reflection layer 2 can be formed in a pattern, one may be formed as a uniform layer and the other may be formed in a pattern.

Examples of the polymerizable cholesteric liquid crystal material include compounds represented by the following general formula (1) and compounds represented by the formulas (2) to (10). These examples are monomers, but may be oligomers or polymers. Two or more kinds selected from the compounds represented by the general formula (1) and the compounds represented by the formulas (2) to (10) are used in combination of two or more compounds represented by the general formula (1) You may use together.

In the above general formula (1), R ¹ and R ² each represent hydrogen or a methyl group, and X is preferably a chlorine or methyl group. Moreover, it is preferable when a and b which show the chain length of the alkylene group which is a spacer of the compound represented by General formula (1) are the range of 2-9 to express liquid crystallinity.

You may mix | blend the chiral agent represented by following formula (11)-Formula (13) with said liquid crystalline compound.

In the above formula (11), R ³ represents hydrogen or a methyl group. In the above formulas (11) and (12), Y is any one of formulas (i) to (xxiv) represented by the following formulas (14) and (15). In the above formulas (11) to (13), c, d, and e, which indicate the chain length of the alkylene group, are preferably in the range of 2 to 9 in terms of exhibiting liquid crystallinity.

  The above-mentioned cholesteric liquid crystal material and chiral agent include, as an example, an ultraviolet polymerization initiator, further a solvent and a diluent, as an example, cholesteric liquid crystal material: chiral agent: ultraviolet polymerization initiator = 100: 5: 5 (mass basis) It is preferable to prepare a coating solution having a concentration of about 30% by mass by mixing at a blending ratio of and dissolving the powder obtained by mixing using a solvent such as toluene. The blending ratio can be appropriately determined depending on the type of cholesteric liquid crystal material, chiral agent, or ultraviolet polymerization initiator to be used, the coating method or coating machine, or the desired coating amount.

  The heat-sensitive recording layer 3 constituting the heat-sensitive recording medium 1 is composed of, for example, an electron donating dye precursor and an electron accepting compound as main components. As the electron-donating dye precursor, any leuco dye that is applied to this kind of heat-sensitive material is arbitrarily applied, and it can be applied to yellow, magenta, cyan, or other hue systems depending on the application. A color is selected. For example, leuco compounds such as triphenylmethane, fluorane, phenothiazine, auramine, spiropyran, and indinophthalide are preferably used.

  The electron-accepting compound is used as a developer in combination with an electron-donating dye precursor, and specifically includes the following acidic substances. That is, phenolic substances such as bisphenol A, octylphosphonic acid, nonylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, etc., α-hydroxy Organic acids such as octanoic acid, α-hydroxydodecanoic acid, α-hydroxytetradecanoic acid, α-hydroxyhexadecanoic acid, or α-hydroxyoctadecanoic acid, metal complex compounds, thio Diphenylurea or quinones.

  The electron-donating dye precursor and the electron-accepting compound are dispersed in a binder resin to constitute the heat-sensitive recording layer 3. Binder resins include starches, celluloses, gelatin, casein, polyvinyl alcohols, maleic anhydride copolymers, acrylics, styrene? A butadiene copolymer emulsion, a urea resin, a melamine resin, an amide resin, a polyurethane resin, or the like can be used. Various auxiliary agents such as polyethylene wax or glyoxal as an antifoaming agent and stearin as a sensitizer are used. Acid amides, behenic acid amides, methylene bis stearic acid amides, dibenzyl oxalate, tolylbiphenyl ether and the like, or pigments such as kaolin, clay, calcium carbonate, titanium oxide, styrene, silica and the like. The heat-sensitive recording layer 2 made of the above materials is usually a colorless, transparent or slightly haze layer. However, as long as the thickness is not excessive, it does not impair the transparency and has transparency in that sense. .

  When two or more heat-sensitive recording layers 2 are provided, the materials constituting the layers can be selected so that the coloring hues of the layers are different, and two or more colors can be developed. When two or more thermosensitive recording layers 2 are provided, the materials constituting the thermosensitive recording layer 2 are selected and formed so that the energy required for each layer to develop color differs. In the case where the thermal recording layer 2 is laminated as two or more layers in contact with each other, for example, the thermal recording layer 2 is already provided based on the action of the solvent in the ink used to form the thermal recording layer to be provided later. Since the electron-donating dye precursor and the electron-accepting compound in the heat-sensitive recording layer may react with each other to develop a color, two or more different heat-sensitive recording layers or between another layer and the heat-sensitive recording layer May be provided with an intermediate layer made of a resin or the like for the purpose of separating the layers. By providing an intermediate layer, it is possible to create a difference in energy required for each of two or more different thermosensitive recording layers to develop a color, that is, an energy gap, so that each layer can be selectively colored, and each The boundary when the layer is colored can be clarified, that is, the contrast can be clarified.

  FIG. 2A is a diagram showing a label form suitable for applying the thermal recording medium of the present invention to a target article. In FIG. 2A, a laminated structure (thermosensitive recording medium 1) of the light selective reflection layer 2 and the thermosensitive recording layer 3 is laminated on the sheet-like substrate 5 from the lower side constituting the thermosensitive recording medium 1, and the thermosensitive recording is performed. A protective layer 7 is laminated on the layer 3, and an adhesive layer 6 is laminated on the lower side of the sheet-like substrate 5 to constitute a heat-sensitive recording medium label 4. The sheet-like base material 5 should be present as an object to be formed when forming the color change layer (light selective reflection layer) 2 or the heat-sensitive recording layer 3 and in the sense of imparting mechanical strength to the heat-sensitive recording medium 1. Although preferred, it can be omitted. The protective layer 7 is for increasing the durability after the thermal recording medium label 4 is applied to the target article using the adhesive layer 6, but can also be omitted. As shown in FIG. 2B, the color change layer (light selective reflection layer) 2 and the thermal recording layer 3 in the thermal recording medium label 4 are opposite to the case described with reference to FIG. The heat-sensitive recording layer 3 and the color change layer (light selective reflection layer) 2 may be laminated in this order from the sheet-like substrate 5 side. Alternatively, the sheet-like substrate 5 may be the uppermost layer, and the sheet-like substrate 5, the heat-sensitive recording layer 3, the color change layer (light selective reflection layer) 2, and the adhesive layer 6 may be laminated in this order from the upper side. In this case, the protective layer 7 may be laminated on the upper side of the sheet-like substrate 5. Of course, the sheet-like substrate 5 may be the uppermost layer, and the sheet-like substrate 5, the color change layer (light selective reflection layer) 2, the thermal recording layer 3, and the adhesive layer 6 may be laminated in this order from the upper side. In this case, the protective layer 7 may be laminated on the upper side of the sheet-like substrate 5.

  FIG. 2 (c) is a view showing a form of a transfer sheet suitable for applying the thermal recording medium of the present invention to a target article. In FIG. 2B, a protective layer 7 and a color are formed on the upper side of the laminated structure (thermosensitive recording medium 1) of the color change layer (light selective reflection layer) 2 and the thermosensitive recording layer 3 from the lower side constituting the thermosensitive recording medium 1. An adhesive layer 6 is laminated below the change layer (light selective reflection layer) 2, and a protective layer 7 is detachably laminated with the sheet-like substrate 5 to constitute a thermal recording medium transfer sheet 8. The adhesive layer 6 may not be provided on the transfer sheet side as long as the adhesive layer is formed on the surface of the target article during transfer. The protective layer 7 is for increasing the durability of the surface of the transferred material after the transfer to the target article using the heat-sensitive recording medium transfer sheet 8 and the adhesive layer 6. It can also be omitted. As shown in FIG. 2D, the thermal recording medium transfer sheet 8 has a laminated structure (thermal recording medium) of a thermal recording layer 3 and a color change layer (light selective reflection layer) 2 from the lower side constituting the thermal recording medium 1. A protective layer 7 is laminated on the upper side of 1), and an adhesive layer 6 is laminated on the lower side of the heat-sensitive recording layer 3, and the protective layer 7 is laminated so as to be peelable from the sheet-like substrate 5 to form a heat-sensitive recording medium transfer sheet 8. It may be. Also in this case, the adhesive layer 6 and / or the protective layer 7 can be omitted.

  In the thermal recording label 4 and the thermal transfer sheet 8 described with reference to FIGS. 2A and 2B, the laminated structure of the color change layer (light selective reflection layer) 2 and the thermal recording layer 3 is as follows. Any thermal recording medium 1 as described with reference to FIG. 1 may be substituted, and the order of stacking the light selective reflection layer and the thermal recording layer may be arbitrary.

  The sheet-like substrate 5 is preferably used as a formation target when forming the color change layer (light selective reflection layer) 2 or the heat-sensitive recording layer 3 and also has a meaning of imparting mechanical strength to the heat-sensitive recording medium 1. However, it can be omitted.

  As the sheet-like base material 5, it is possible to reduce the thickness, and it is preferable to have a solvent resistance and a heat resistance that can withstand the processing when manufacturing the medium for mechanical strength and authenticity determination. Since it depends on the purpose of use, it is not limited, but a film-like or sheet-like plastic is preferable. For example, various plastic films or plastic sheets such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, polyethylene / vinyl alcohol, etc. are exemplified. be able to.

  When an alignment film is required, any alignment film such as polyvinyl alcohol resin (PVA) or polyimide resin can be used as long as it can be used as an alignment film. The alignment film is rubbed by rubbing with a cloth, a brush or the like after applying a solvent solution of these resins to the surface of the sheet-like substrate 5 as described above by an appropriate application method and drying. Etc. are formed.

  The adhesive layer 6 is for applying the heat-sensitive recording medium 1 of the present invention to a target article. As the adhesive constituting the adhesive layer 6, a heat-sensitive adhesive or a pressure-sensitive adhesive can be used. In any case, in the case of the thermal recording medium label 4, a pressure-sensitive adhesive that can be attached only by pressure is often used, and in the case of the thermal recording medium transfer sheet 8. In many cases, a heat-sensitive adhesive is used to enable instant transfer with heat and pressure.

  In addition to the general protection of the thermosensitive recording medium 1, the protective layer 7 prevents surface deformation caused by heat and pressure caused when recording on the thermosensitive recording layer 3, chemical resistance, water resistance, and friction resistance. In addition to improving the properties and head matching properties, it is also used for the purpose of improving transparency. As a material constituting the protective layer 7, a resin composition having desired physical properties as the surface protective layer is selected from those already mentioned as the binder resin constituting the thermosensitive recording layer 3. In particular, when surface scratch resistance, chemical resistance, and contamination resistance are required, a thermosetting resin, or an ionizing radiation curable resin such as an ultraviolet curable resin or an electron beam curable resin is usually used. It is preferable that the protective layer 7 has releasability in order to smoothly carry out relative running between the thermal recording medium 1 and the thermal head during recording on the thermal recording layer 3. For this reason, it is preferable to mix a release material such as silicone in the protective layer 7 or to coat the surface of the protective layer with a material containing the release material. The protective layer 7 is also required to have both printability and slipperiness since printing using a thermal transfer ribbon may be performed after the thermal recording medium 1 is used so that unauthorized rewriting cannot be performed. Sometimes. In this case, after a layer having printability is first formed, a material including a releasable substance is used, for example, a point having a diameter of about 0.1 mm and a line having a width of about 0.1 mm are set to 0. By arranging the portions having the releasability and the portions having the printability by arranging them at intervals of about 2 mm or more, it is possible to have both properties.

  In the thermal recording medium transfer sheet 8, it is preferable that the thermal recording medium 1 is detachably laminated with the sheet-like substrate 5. When the protective layer 7 and other layers are interposed, it is only necessary to ensure releasability between the sheet-like substrate and the layer in contact with the sheet-like substrate. Even if it is said to be peelable, an adhesive strength that does not peel is required until just before transfer. When a PET film is used as the sheet-like substrate, most of the binder resins in the paint or ink do not adhere firmly to the PET film and can be peeled off during transfer. If necessary, a binder resin having high adhesiveness may be added to increase the peel strength, or a peelable binder resin or material such as wax may be added to lower the peel strength.

  FIG. 3 is a diagram showing a laminated structure of an information recording medium 9 which is an application example utilizing the effect exhibited by the thermal recording medium 1 of the present invention. As shown in FIG. 3 (a), the information recording medium 9 has a color change layer from the lower side, for example, a laminate composed of the light selective reflection layer 2, the thermosensitive recording layer 3, and the protective layer 7 on the substrate 10. A laminated structure in which the light selective reflection layer 2 side is laminated so that the magnetic recording layer 11 is laminated on the lower surface side of the substrate 10 may be used, or as shown in FIG. The information recording medium 9 has a laminated body composed of a thermal recording layer 3, a color change layer, for example, a light selective reflection layer 2, and a protective layer 7 from the lower side so that the thermal recording layer 3 side is in contact with the substrate 10. A laminated structure in which the magnetic recording layer 11 is laminated on the lower surface side of the substrate 10 may be used.

  When the thermal recording layer 3 of the information recording medium 9 as shown in FIG. 3B is subjected to thermal recording, the color change layer (light) on the portion (= recording portion) colored by the recording of the thermal recording layer 3 is recorded. Due to the action of the selective reflection layer 2, an effect is produced in which the color of the recording portion appears to change when viewed from the upper surface side of the figure. For example, when the heat-sensitive recording layer 3 has two layers for black color development and red color development, by performing thermal recording, there is no color development with a red color recording part and a black color recording part. A solid visual part is produced, but a complicated visual effect is generated in which the color changes on the recording part colored in red, on the recording part colored in black, and on the plain part not colored. In this way, it is possible to make it difficult to counterfeit or to counterfeit a thing with a complicated visual effect, and it is possible to suppress copying using a color copier.

  FIG. 4 shows one embodiment of the information recording medium 9 of the present invention. From the lower surface side of the figure, the magnetic recording layer 11, the substrate 10, the intermediate layer 12A, the thermal recording layer A (reference numeral 3A), the intermediate The layer 12B, the thermosensitive recording layer B (reference numeral 3B), the light selective reflection layer 2 as a color change layer, and the protective layer 7 are laminated. The role of the intermediate layer B (reference numeral 12B) is as described above, but the role of the intermediate layer A is to prevent the thermal recording layer A from developing color when the substrate 10 and the thermal recording layer A are laminated. This is to thermally cut off between the material 10 and the heat-sensitive recording layer A.

  The laminate composed of the base material 10 and the magnetic recording layer 11 is widely used for various cards such as credit cards or savings cards, transportation commuter passes, identification cards, etc. The magnetic recording layer 11 Various information is recorded as invisible information, the recorded information is read using reading means, and predetermined steps are executed to settle the purchase price, deposit or withdraw cash, or pass through the gate , Etc. are performed.

  The base material 10 has strength and thickness according to the application, and is made of the same plastic film or plastic sheet as the material constituting the sheet-like base material 5 or paper, and if necessary, 2 -3 sheets or more may be combined.

  The magnetic recording layer 11 is (1) provided by directly applying to a base material 10 using a magnetic paint prepared by adding a material containing magnetic agent powder and kneading. (2) What is the base material 10? Applied to another thin plastic film, etc., cut into stripes and attached to the card substrate 10, or (3) Magnetic recording layer transfer prepared by being peelably laminated on a temporary substrate The sheet is formed by being transferred to the base material 10 by a transfer method. The magnetic recording layer 11 is formed as a thin film of a magnetic substance in a gas phase by vapor deposition or sputtering of the magnetic substance on the base material 10, or the formation of such a thin film is a base of a magnetic recording medium. It may be performed on a base material different from the material, and then cut and pasted into a stripe shape or applied by transfer.

  In the thermal recording 3 of the information recording medium 9, for example, information such as the name and number of each owner, the valid period, the boarding section, or the amount of money is recorded as visual information, and it is configured so that visual determination is possible. ing.

  In addition, the color change layer (light selective reflection layer) 2 of the information recording medium 9 in the above example has an effect that the hue changes depending on the viewing angle, thus giving an impression that reproduction by color copying is difficult and preventing forgery. Effect. Further, when the color change layer 2 is a light selective reflection layer, it has a light selective reflection property that reflects either left circularly polarized light or right circularly polarized light in incident light. By making the polarized light incident, more simply, by overlapping the left circularly polarizing plate or the right circularly polarizing plate, either circularly polarizing plate or any circularly polarizing plate can be attached according to its characteristics. The authenticity of the information recording medium 9 can be determined by confirming that reflection does not occur when the images are overlapped and that the other is reflected.

  In the information recording medium 9 of the above example, the magnetic recording layer 11 is provided as the information recording means on the base material 10. However, the magnetic recording layer 11 may be replaced with an IC chip, or the magnetic recording layer 11 And an IC chip may be provided.

In the information recording medium 9 of the present invention, in addition to visual information recording performed using the thermosensitive recording layer 3,
Issuing organization name, card name, precautionary statement, explanatory text, information such as the amount of money to use as a voucher, etc., any pattern or pattern may be given, such information, pattern, or The coloring pattern can be formed by any means such as printing, and the portion to be formed may be any portion as long as it does not interfere with the recording on the thermal recording layer 3, and the thermal recording medium described above. 1, any part of the thermal recording medium label 4 or the thermal recording medium transfer sheet 8 may be used.

  A magnetic paint (barium ferrite: urethane resin: carbon = 36: 12: 2 50% solvent solution (solvent; toluene: MEK: MIBK = 20: 15: 15) was applied to the surface of a PET film having a thickness of 188 μm. A magnetic recording layer was formed by drying and aging at a temperature of 80 ° C. After forming the magnetic recording layer, an ultraviolet curable cholesteric liquid crystal paint was applied to the surface opposite to the magnetic recording layer. The cholesteric liquid crystal layer was formed by irradiating with ultraviolet light and then cured to form a polymerizable nematic liquid crystal (trade name; “PAlio Color” manufactured by BASF Corporation). LC242 "), a chiral agent (trade name;" Palio Color LC756 "manufactured by BASF Corporation) and an ultraviolet polymerization initiator This is a 20% solution (the solvent is toluene). Among these, the mixing ratio of polymerizable nematic liquid crystal / chiral agent is 95.5 / 4.5, and the ultraviolet polymerization initiator is 5 with respect to the polymerizable nematic liquid crystal. % Blended.

  On the formed cholesteric liquid crystal layer, a heat-sensitive recording layer for black color development and a protective layer were sequentially formed to obtain an information recording medium. As a coating material for forming a heat-sensitive recording layer for black color development, 3- (N-ethyl-N-acylamino) -6-methyl-7-anilinofluorane, bisphenol A, and a binder solution (10% aqueous solution of polyvinyl alcohol) are used. A urethane acrylate resin solution was used as the protective layer-forming paint.

  An information recording medium was obtained in the same manner as in Example 1 except that the cholesteric liquid crystal layer was formed in a pattern and two layers for black color development and red color development were formed as the heat-sensitive recording layer. In order to form the cholesteric liquid crystal layer in a pattern, a gravure printing method was used. Further, the same coating material as in Example 1 was used as the heat-sensitive recording layer forming paint for black color development, and 3-diethylamino-7-chlorofluorane, 3 , 3-dichlorophenylthiourea and a binder solution (10% aqueous solution of polyvinyl alcohol) were used.

(Create transfer sheet)
A cholesteric liquid crystal layer was formed in the same manner as in Example 1 on the surface of a PET film having a thickness of 25 μm.

  On the cholesteric liquid crystal layer, a heat-sensitive recording layer for red color development, a heat-sensitive recording layer for black color development, and a resin layer for protecting the heat-sensitive recording layer were sequentially laminated to obtain a transfer sheet. The heat-sensitive recording layer forming paint for red color development is the same as that in Example 2, and the heat-sensitive recording layer forming paint for black color development and the protective layer forming paint are those described in Example 1. The same thing was used.

(Transfer to substrate)
Separately from the above transfer sheet, a PET film having a thickness of 188 μm was newly prepared, and a magnetic paint (barium ferrite: urethane resin: carbon = 36: 12: 2 50% solvent solution (solvent; toluene: MEK) : MIBK = 20: 15: 15) and dried, and after aging at a temperature of 80 ° C., the protective layer side of the transfer sheet is in contact with the surface on which the magnetic paint is not applied. Then, they were pressure-bonded, transferred, and the PET film of the transfer sheet was peeled off.

  A peelable varnish made of an acrylic resin solution is applied to the surface of a PET film having a thickness of 25 μm to form a release layer. A polyimide resin solution is applied onto the release layer and dried, followed by rubbing. This was performed in the same manner as in Example 3 except that an alignment film was formed and then a cholesteric liquid crystal layer was formed on the alignment film.

  The same as in Example 1, except that the black color heat-sensitive recording layer and the protective layer were formed on a part of the cholesteric liquid crystal layer, and the black color heat-sensitive recording layer and the protective layer were not formed. A polyurethane resin solution was applied on the portion, dried, and then aged to form an image receiving layer. Further, on the side on which the magnetic recording layer was formed, an explanatory note was printed on the surface of the magnetic recording layer, and a protective layer was further laminated.

  In the same manner as in Example 3, except that after this, a black color thermosensitive recording layer, a red color thermosensitive recording layer, and a protective layer were formed on a part of the cholesteric liquid crystal layer. A polyurethane resin solution was applied on the portions where the two types of heat-sensitive recording layers for red color development and the protective layer were not formed, dried, and then subjected to aging to form an image receiving layer. Further, on the side on which the magnetic recording layer was formed, an explanatory note was printed on the surface of the magnetic recording layer, and a protective layer was further laminated.

It is a figure which shows the thermosensitive recording medium of this invention. It is a figure which shows the form which applies the thermosensitive recording medium of this invention to a target article. It is a figure which shows the information recording medium of this invention. It is a figure which shows the other information recording medium of this invention.

Explanation of symbols

1 ... thermal recording medium 2 ... color change layer (light selective reflection layer)
3 ... Thermal recording layer 4 ... Thermal recording medium label 5 ... Sheet-like base material 6 ... Adhesive layer 7 ... Protective layer 8 ... Thermal recording medium transfer sheet 9 ... Information recording medium 10 ... Base material 11 ... Magnetic recording layer

Claims (7)

  A heat-sensitive recording medium comprising a color-changing layer that gives different colors depending on a viewing angle and a heat-sensitive recording layer that develops color when heated.   2. The thermal recording medium according to claim 1, wherein the color change layer is a light selective reflection layer having a light selective reflection property that reflects either left circularly polarized light or right circularly polarized light in incident light.   In claim 1, at least one of the color change layer and the thermosensitive recording layer, or in claim 2, at least one of the light selective reflection layer and the thermosensitive recording layer is composed of two or more layers. A thermal recording medium.   A thermal recording medium label, wherein an adhesive layer is laminated on a laminate in which the thermal recording medium according to any one of claims 1 to 3 and a sheet-like substrate are laminated.   A thermal recording medium transfer, wherein the thermal recording medium side of the laminate comprising the thermal recording medium according to any one of claims 1 to 3 and an adhesive layer is detachably laminated with a sheet-like substrate. Sheet.   An information recording medium, wherein the substrate is provided with information recording means, and the thermal recording medium according to any one of claims 1 to 3 is further laminated. 7. The information recording medium according to claim 6, wherein the information recording means is a magnetic recording layer or an IC chip.

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