JP4960698B2 - Reversible thermosensitive recording medium and method for producing the same - Google Patents

Description

  The present invention relates to a reversible thermosensitive recording medium and a method for producing a reversible thermosensitive recording medium.

  It is known that a reversible thermosensitive recording medium incorporating an IC chip module can rewrite internal information of the IC chip and display the recorded information as a visible image on the reversible thermosensitive recording medium. Such a reversible thermosensitive recording medium is used as instructions such as a work book, a parts management slip, and a process management slip in the manufacturing industry. Specifically, after the instruction sheet is used by wrapping around a round bar-shaped part or in a card case, dirt attached to the instruction sheet is washed, and the instruction sheet is rewritten with a printer. When an image is formed on the instruction sheet and when the image formed on the instruction sheet is erased, the instruction sheet is pressed against a heating device such as a thermal head, an erasing bar, an erasing roller, or an erasing plate of the printer. For this reason, when the instruction sheet is rewritten, it is necessary to prevent the IC chip module from being damaged and to prevent the adhesive from flowing out from the bonding portion between the IC chip module and the reversible thermosensitive recording medium. Further, when cleaning the instruction sheet, it is necessary to prevent the IC chip module from being peeled off from the reversible thermosensitive recording medium. Further, the instruction sheet needs to have flexibility and good image quality.

  Patent Document 1 discloses a reversible thermosensitive layer 114b containing at least one reversible heat-sensitive layer 114b which usually contains a colorless or light leuco dye and a reversible developer that causes the leuco dye to develop color by heating and decolorize by reheating. The heat sensitive recording sheet 114 is used as one oversheet, and the core material 113 is interposed between the other oversheet (film substrate 111) in which the IC chip module 112 is incorporated or into which the IC chip module 112 is incorporated and the reversible thermosensitive recording sheet 114. It is disclosed that an IC card is formed by injection molding or heat-bonding both sheets via a core material 113 (see FIG. A).

However, such an IC card has a problem that it has no flexibility because of its high rigidity.
JP-A-11-154210

  The present invention provides a reversible thermosensitive recording medium having excellent water resistance, good image quality, and flexibility, and a method for producing the reversible thermosensitive recording medium, in view of the above-described problems of the prior art. For the purpose.

According to the first aspect of the present invention, there is provided a base sheet, an inlet having an IC chip, a core sheet in which a through hole is formed, and a reversible thermosensitive recording sheet in which a reversible thermosensitive recording layer is formed via an adhesive layer. a reversible thermosensitive recording medium are sequentially bonded, said with IC chip penetrates the through hole, the reversible thermosensitive recording sheet of the reversible thermosensitive recording layer side surface is the core is not formed is bonded to the sheet and the counter, the core sheet is characterized in that a layer containing a pigment and a synthetic rubber-based copolymer is paper that is formed on both sides.

According to a second aspect of the present invention, in the reversible thermosensitive recording medium according to the first aspect, the IC chip is bonded so as to protrude from the through hole to the reversible thermosensitive recording sheet side by -5 μm or more and 45 μm or less. and characterized in that it.

  According to a third aspect of the present invention, in the reversible thermosensitive recording medium according to the first or second aspect, the adhesive layer contains an acrylic resin.

Invention according to claim 4, in the reversible thermosensitive recording medium according to any one of claims 1 to 3, wherein the synthetic rubber-based copolymer, a styrene - wherein the butadiene-based copolymer And
The invention according to claim 5 is the reversible thermosensitive recording medium according to claim 4, wherein the layer containing the pigment and the synthetic rubber copolymer further contains an acrylic copolymer. To do.

  The invention according to claim 6 is the reversible thermosensitive recording medium according to any one of claims 1 to 5, wherein the reversible thermosensitive recording layer has a structural formula.

（式中、Ｘ及びＹは、それぞれ独立に、ヘテロ原子を有する２価の有機基であり、Ｒ^１は、置換又は無置換の２価の炭化水素基であり、Ｒ^２は、置換又は無置換の１価の炭化水素基であり、ａは、１以上３以下の整数であり、ｂは、１以上２０以下の整数であり、ｃは、０以上３以下の整数である。）
で表される化合物及び／又は構造式

(In the formula, X and Y are each independently a divalent organic group having a hetero atom , R ¹ is a substituted or unsubstituted divalent hydrocarbon group , and R ² is substituted or unsubstituted. a monovalent hydrocarbon group substituted, a is 1 to 3 an integer, b is 1 to 20 integer, c is is an integer of 0 to 3.)
And / or a structural formula represented by

（式中、Ｚは、ヘテロ原子を有する２価の有機基であり、Ｒ^３は、置換又は無置換の２価の炭化水素基であり、Ｒ^４は、置換又は無置換の１価の炭化水素基であり、ｄは、１以上３以下の整数である。）
で表される化合物と、ロイコ染料を含有することを特徴とする。

(In the formula, Z is a divalent organic group having a hetero atom , R ³ is a substituted or unsubstituted divalent hydrocarbon group , and R ⁴ is a substituted or unsubstituted monovalent carbon group. A hydrogen group , and d is an integer of 1 or more and 3 or less.)
And a leuco dye.

The invention according to claim 7, the substrate sheet on which the adhesive layer is formed, the inlet, the reversible thermosensitive core sheet及beauty viscosity sealable layer of the adhesive layer is formed is formed a recording sheet having an IC chip a way you produce reversible thermosensitive recording medium using a reversible thermosensitive recording sheet is reversible thermosensitive recording layer is formed on the surface on which the adhesive layer is not formed, the The core sheet is a paper in which a layer containing a pigment and a synthetic rubber copolymer is formed on both sides, and the surface of the inlet that does not have the IC chip is pressure bonded to the base sheet. And a step of forming a through hole in the core sheet, a base material sheet to which the inlet is adhered , a core sheet having the through hole formed therein and the reversible thermosensitive recording sheet, and the IC chip having the through hole. with penetrating, reversible thermosensitive recording Sea Surface of the reversible thermosensitive recording layer is not formed side is characterized by having a step of sequentially pressure bonding so as to face the said core sheet.

  According to the present invention, it is possible to provide a reversible thermosensitive recording medium having excellent water resistance, good image quality, and flexibility, and a method for producing the reversible thermosensitive recording medium.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of the thermal recording medium of the present invention. 1A is a top view, and FIG. 1B is a cross-sectional view taken along a line AA ′ in FIG. The thermosensitive recording medium shown in FIG. 1 has a base sheet 11, an inlet 12 having an IC chip 12a on a base 12b, a core sheet 13 having a through hole, and a reversible thermosensitive recording layer 14a on a base sheet 14b. The heat-sensitive recording sheet 14 is sequentially bonded through the adhesive layers 15, 16 and 17. In the reversible thermosensitive recording medium shown in FIG. 1, the IC chip 12a passes through the through hole of the core sheet 13, and the side of the reversible thermosensitive recording sheet 14 that does not have the reversible thermosensitive recording layer 14a is the core. The sheet 13 is bonded so as to face the sheet 13. At this time, the IC chip 12a is bonded so as to protrude from the through hole of the core sheet 13 to the reversible thermosensitive recording sheet 14 side by −5 to 45 μm, preferably 0 to 40 μm, more preferably 0 to 35 μm. Thereby, when the thermal recording medium is pressed against the heating device of the printer, it is possible to suppress defects in image formation and erasure due to the unevenness of the region having the IC chip 12a.

  FIG. 2 shows an example of an inlet used in the present invention. In an inlet 12 shown in FIG. 2, an IC chip 12a and an antenna circuit 12c are formed on a base material 12b, and the IC chip 12a and the antenna circuit 12c are electrically connected. The thickness of the IC chip 12a is preferably 150 to 200 μm. As the base material 12b, a rigid type such as general paper phenol, glass epoxy, and composite, a flexible type such as polyimide film, polyester film, paper, and synthetic paper, and a composite type of both can be used. The thickness of the base material 12b is preferably 30 to 100 μm. Further, in order to protect the IC chip 12a, a protective film such as a polyimide film, a polyester film, or paper can be adhered to the surface of the base 12b having the IC chip 12a. The thickness of the protective film is preferably 10 to 60 μm.

  The thickness of the inlet 12 is preferably 180 to 360 μm.

  The inlet 12 is not particularly limited, and inlets made by OMRON, Alien Technology, Sony, Fujitsu, Hitachi, Texas Instruments, etc. can be used.

  The adhesive layers 15, 16 and 17 can be formed using an adhesive. The pressure-sensitive adhesive is usually one that can be pressure-bonded at room temperature. For example, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin, vinyl acetate-acrylic copolymer, ethylene-vinyl acetate copolymer Polymer, acrylic resin, polyvinyl ether resin, vinyl chloride-vinyl acetate copolymer, polystyrene resin, polyester resin, polyurethane resin, polyamide resin, chlorinated polyolefin resin, polyvinyl butyral resin, acrylic acid Examples include ester copolymers, methacrylate ester copolymers, natural rubber, synthetic rubber, cyanoacrylate resins, silicone resins, EVA resins, and the like. The main component of the pressure-sensitive adhesive is preferably natural rubber, synthetic rubber, acrylic resin, silicone resin, polyurethane resin, styrene-isoprene-styrene block copolymer, EVA resin, and acrylic resin. Particularly preferred. Thereby, the curvature of a reversible thermosensitive recording medium can be suppressed. The type of pressure-sensitive adhesive and the thickness of the pressure-sensitive adhesive layer can be appropriately selected in consideration of the type of adherend, the environment in which it is used, the adhesive strength, and the like. The pressure-sensitive adhesive may contain various additives, inorganic fillers, organic fillers, and fiber materials.

  It is preferable that the thickness of the adhesion layers 15, 16 and 17 is 20-100 micrometers each independently.

  As the core sheet 13, paper, resin sheet, rubber sheet, synthetic paper, metal sheet, glass sheet, or a composite thereof can be used. Among these, water-resistant paper having a water-resistant layer containing a pigment and a synthetic rubber copolymer on both sides is preferable. Thus, when the reversible thermosensitive recording medium is rewritten, the damage of the inlet 12 is suppressed, and a reversible thermosensitive recording medium having flexibility is obtained, so that defects in image formation and erasure can be suppressed. , The operator can easily handle.

  The thickness of the core sheet 13 is preferably 50 to 200 μm.

  The waterproof paper is obtained by applying a coating solution containing a pigment and a synthetic rubber copolymer on both sides of the base paper. In order to form a coating film having high water resistance using a dispersion, the hydrophobicity of the dispersoid and the dispersant are important. A soap-free dispersion is ideal, but it is preferable to use as little dispersant as possible to reduce the interfacial tension. Moreover, in order to form a coating film with high water resistance, it is a necessary condition that the film forming property is good, and it is preferable that the film forming temperature is low.

  The synthetic rubber copolymer is preferably a styrene-butadiene copolymer, and more preferably a styrene-butadiene copolymer having 30 to 70% by weight of a structural unit derived from styrene. The styrene-butadiene copolymer is obtained by copolymerizing methacrylic acid (alkyl), other vinyl compounds, unsaturated carboxylic acids, etc. in addition to styrene and butadiene. By having 70% by weight, preferably 50 to 60% by weight, high water resistance can be obtained. If the structural unit derived from styrene exceeds 70% by weight, the film-forming temperature increases, so the film-forming property may deteriorate.

  A styrene-butadiene copolymer having 30 to 70% by weight of styrene-derived structural units may be used in combination with a butadiene-styrene copolymer having more than 70% by weight of styrene-derived structural units. Acrylic copolymers such as styrene- (meth) acrylic acid alkyl copolymers having 8 or more carbon atoms in the group and alkyl (meth) acrylate copolymers having 8 or more carbon atoms in the alkyl group are used in combination. May be.

  Examples of the pigment include kaolin, calcium carbonate, titanium dioxide, aluminum hydroxide, amorphous silica, satin white, talc, zinc oxide, barium sulfate, mica, and the like, among which those having a high plate-like aspect ratio are preferable.

  In addition, it is preferable that the weight ratio of the synthetic rubber-type copolymer with respect to a pigment is 0.6-2.

  The water-resistant layer can also contain water repellents such as paraffin, microcrystalline wax, polyethylene, and higher fatty acid derivatives. Furthermore, the water resistant layer may contain polyethylene, metal soap, and the like.

  Water-resistant layer can be dispersed, thickener, fluidity improver, antifoaming agent, colorant, antiseptic / antifungal agent, deodorant, UV absorber, lubricant, antiblocking agent, interface as required. You may further contain an activator, a plasticizer, a pH adjuster, etc.

The base paper is preferably a water-resistant base paper having a Cobb water absorption of 30 g / m ² or less using a 1.0% or higher emulsion of a modified rosin and a metal salt, and the Cobb water absorption is 20 g / m ^2. The water resistant base paper described below is more preferable. The modified rosin is preferably a rosin modified with an α, β-unsaturated polybasic acid, and the metal salt is preferably an aluminum salt. In particular, it is preferable to use a modified rosin having a softening point of 110 ° C. or higher for use in contact with high-temperature water, and it is also effective to esterify a part of the carboxylic acid.

  The water-resistant layer can be formed using a coating method such as an air knife coating method, a die coating method, a blade coating method, a knife coating method, a roll coating method, a kiss coating method, a wire bar coating method, or a comma coating method. In the process of forming such a water-resistant layer, the evaporation of moisture after coating may destroy the coating film and form pinholes, and shrinkage during drying may form cracks. In order to suppress the occurrence of such defects, the number of times of application (one side) can be set to 2 times or more.

The coating amount (solid content) of the water-resistant layer (one surface) is preferably 8 g / m ² or more, and more preferably 12 g / m ² or more. When the coating amount is less than 8 g / m ² , the water resistance may be insufficient.

  FIG. 3 shows an example of a reversible thermal recording sheet used in the present invention. In the reversible thermosensitive recording sheet shown in FIG. 3, a reversible thermosensitive recording layer 14a, an intermediate layer 14c, and a protective layer 14d are laminated on one surface of a substrate sheet 14b, and a back layer 14e is formed on the other surface. It may be formed.

  The reversible thermosensitive recording layer 14a is a thermosensitive layer whose color tone changes reversibly, and contains a reversible thermosensitive recording material whose color state changes reversibly with temperature. The reversible thermosensitive recording material changes its color state by combining changes in transmittance, reflectance, absorption wavelength, scattering degree, and the like.

  The reversible thermosensitive recording material is not particularly limited as long as the transparency and color tone are reversibly changed by heat.For example, the reversible thermosensitive recording material is in a first color state at a first temperature higher than room temperature. The material which will be in the state of a 2nd color by heating at 2nd temperature higher than this, and cooling after that is mentioned. In particular, a material whose color state changes between the first temperature and the second temperature is preferable. Specifically, a material that becomes transparent at the first temperature and becomes cloudy at the second temperature (see Japanese Patent Application Laid-Open No. 55-154198), develops color at the second temperature, and disappears at the first temperature. Material to be colored (refer to JP-A-4-224996, JP-A-4-247985, JP-A-4-267190), a material which becomes cloudy at a first temperature and becomes transparent at a second temperature ( JP-A-3-169590), a material that develops black, red, blue, etc. at a first temperature and decolors at a second temperature (JP-A-2-188293, JP-A-2-188294) For example). Among these, a system in which an organic low molecular weight substance such as a higher fatty acid is dispersed in a resin base material or a system using a leuco dye and a developer is preferable.

  Although it does not specifically limit as a leuco dye, A phthalide compound, an azaphthalide compound, a fluoran compound, etc. are mentioned, You may use 2 or more types together. Examples of the developer include those disclosed in JP-A-5-124360, JP-A-6-210554, and JP-A-10-95175, and two or more of them may be used in combination. .

  The developer is a structure having a color developing ability to develop a leuco dye in the molecule (for example, phenolic hydroxyl group, carboxylic acid group, phosphoric acid group, etc.) and a structure for controlling the cohesive force between molecules (for example, A compound having one or more structures in which long-chain hydrocarbon groups are linked. These structures may be linked via a divalent or higher valent linking group having a hetero atom. Further, the long chain hydrocarbon group may have the same linking group and / or aromatic group. Examples of such a developer include those disclosed in JP-A-9-290563 and JP-A-11-188969. Above all, structural formula

（式中、Ｘ及びＹは、それぞれ独立に、ヘテロ原子を有する２価の有機基を表す。Ｒ^１は、置換又は無置換の２価の炭化水素基を表す。Ｒ^２は、置換又は無置換の１価の炭化水素基を表す。ａは、１〜３の整数を表し、ｂは、１〜２０の整数を表し、ｃは、０〜３の整数を表す。）
で表される化合物及び構造式

(In the formula, X and Y each independently represent a divalent organic group having a hetero atom. R ¹ represents a substituted or unsubstituted divalent hydrocarbon group. R ² represents substituted or unsubstituted. A substituted monovalent hydrocarbon group, a represents an integer of 1 to 3, b represents an integer of 1 to 20, and c represents an integer of 0 to 3).
And a structural formula represented by

（式中、Ｚは、ヘテロ原子を有する２価の有機基を表す。Ｒ^３は、置換又は無置換の２価の炭化水素基を表す。Ｒ^４は、置換又は無置換の１価の炭化水素基を表す。ｄは、１〜３の整数を表す。）
で表される化合物の少なくとも一方であることが好ましい。このような顕色剤は、感度が高いため、画像の品質を向上させることができる。

(In the formula, Z represents a divalent organic group having a hetero atom. R ³ represents a substituted or unsubstituted divalent hydrocarbon group. R ⁴ represents a substituted or unsubstituted monovalent carbon group. Represents a hydrogen group, d represents an integer of 1 to 3)
It is preferable that it is at least one of the compounds represented by these. Since such a developer has high sensitivity, the image quality can be improved.

  The reversible thermosensitive recording layer 14a can be added with additives for improving or controlling coating characteristics and color erasing characteristics as required. Examples of the additive include a surfactant, a conductive agent, a filler, an antioxidant, a coloring stabilizer, and a decoloring accelerator.

  The reversible thermosensitive recording layer 14a preferably contains a leuco dye, a developer and an additive together with a binder resin. The binder resin is not particularly limited as long as these materials can be bound onto the base sheet 14b. Among these, in order to improve durability during repetition, a resin cured with heat, ultraviolet (UV), electron beam (EB) or the like is preferable, and a resin cured with a curing agent is particularly preferable. Thereby, a gel fraction can be improved. Examples of the resin that can be thermally cured include acrylic polyol resin, polyester polyol resin, polyurethane polyol resin, polyvinyl butyral resin, cellulose acetate propionate, and cellulose acetate butyrate.

  The curing agent is not particularly limited, but is preferably an isocyanate. As the isocyanate, hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI); adduct type of these isocyanates with trimethylolpropane, burette type, isocyanurate type, Examples thereof include blocked isocyanates. Among these, hexamethylene diisocyanate, this adduct type, burette type, and isocyanurate type are preferable. However, the entire amount of the curing agent may not be cured. That is, an unreacted curing agent may be present in the reversible thermosensitive recording layer 14a. At this time, a curing catalyst may be used to promote the curing reaction.

The reversible thermosensitive recording layer 14a preferably has a gel fraction of 30% or more, more preferably 50% or more, and particularly preferably 70% or more. If the gel fraction is less than 30%, the repeated durability may decrease. The gel fraction can be measured by immersing the coating film in a highly soluble solvent. Specifically, the reversible thermosensitive recording layer 14a is peeled from the base sheet 14b, and the initial weight of the reversible thermosensitive recording layer 14a is measured. Next, the reversible thermosensitive recording layer 14a is placed in a 400-mesh metal mesh, soaked in a solvent in which an uncured binder resin is soluble for 24 hours, and then vacuum-dried, and the weight after drying is measured. Thus, the gel fraction is expressed by the formula: gel fraction (%) = (weight after drying) / (initial weight) × 100
Can be obtained from At this time, the calculation is performed excluding the weight of components other than the binder resin such as the organic low molecular weight material particles in the reversible thermosensitive recording layer 14a. If the weight of the organic low-molecular substance particles is not known in advance, the area ratio per unit area, the binder resin and the organic low-molecular weight can be determined by cross-sectional observation using a transmission electron microscope (TEM), a scanning electron microscope (SEM), or the like. The weight ratio may be calculated from the specific gravity of the molecular substance particles to calculate the weight of the organic low molecular substance particles.

  In the reversible thermosensitive recording layer 14a, the weight ratio of the binder resin to the color forming component is preferably 0.1 to 10. If this weight ratio is less than 0.1, the heat intensity of the reversible thermosensitive recording layer 14a may be insufficient, and if it is more than 10, the color density may decrease.

  The reversible thermosensitive recording layer 14a can be formed using a coating liquid in which a leuco dye, a developer, an additive, a binder resin, and a solvent are uniformly dispersed. Examples of the solvent include alcohols, ketones, ethers, glycol ethers, esters, aromatic hydrocarbons, aliphatic hydrocarbons and the like. The coating solution can be prepared using a dispersion apparatus such as a paint shaker, a ball mill, an attritor, a three-roll mill, a keddy mill, a sand mill, a dyno mill, or a colloid mill. At this time, using a dispersing device, each material may be dispersed in a solvent, or a material in which each material is dispersed may be mixed. Furthermore, it may be precipitated by heating and dissolving each material, followed by rapid cooling or slow cooling. As coating methods, blade coating method, wire bar coating method, spray coating method, air knife coating method, bead coating method, curtain coating method, gravure coating method, kiss coating method, reverse roll coating method, dip coating method, die coating method Etc.

  The thickness of the reversible thermosensitive recording layer 14a can be appropriately selected according to the purpose, and is preferably 1 to 20 μm, more preferably 3 to 15 μm. If the thickness of the reversible thermosensitive recording layer 14a is less than 1 μm, the color density may decrease and the contrast of the image may decrease. If the thickness exceeds 20 μm, the heat distribution of the reversible thermosensitive recording layer 14a increases. As a result, a portion that does not reach the coloring temperature and does not develop color may occur, and the target coloring density may not be obtained.

  The protective layer 14d can contain a resin cured by heat, ultraviolet rays, electron beams, etc., preferably using ultraviolet rays. Examples of materials that can be cured using ultraviolet rays (electron beams) include urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, vinyl, and unsaturated polyester oligomers; Monomers such as polyfunctional acrylates, methacrylates, vinyl esters, ethylene derivatives, and allyl compounds are listed. In addition, when making it bridge | crosslink using an ultraviolet-ray, it is preferable to use a photoinitiator and a photoinitiator. Moreover, as resin which can be thermosetted, the same resin as the above can be used, and it can be hardened similarly to the above.

  The thickness of the protective layer 14d is preferably 0.1 to 10 μm.

  The intermediate layer 14c improves the adhesion of the protective layer 14d to the reversible thermosensitive recording layer 14a, prevents alteration of the reversible thermosensitive recording layer 14a by applying a coating solution for the protective layer 14d, and reversible thermosensitive additive in the protective layer 14d. It is provided to prevent the transition to the recording layer 14a. Thereby, the preservability of an image can be improved.

  The intermediate layer 14c can contain a resin cured by using heat, ultraviolet rays, an electron beam, or the like, or a thermoplastic resin. Examples of the thermosetting resin include polyethylene, polypropylene, polystyrene, polyvinyl alcohol, polyvinyl butyral, polyurethane, saturated polyester, unsaturated polyester, epoxy resin, phenol resin, polycarbonate, and polyamide. Moreover, as what can be hardened | cured using a heat | fever, an ultraviolet-ray, an electron beam, etc., the thing similar to the above can be used and it can harden | cure similarly to the above. The formation method of the intermediate layer 14c is the same as that of the reversible thermosensitive recording layer 14a.

  The intermediate layer 14c may contain a filler, an ultraviolet absorber, and the like as necessary. The content of the filler in the intermediate layer 14c is preferably 1 to 95% by volume, more preferably 5 to 75% by volume. Moreover, it is preferable that content of the ultraviolet absorber in the intermediate | middle layer 14c is 0.5 to 10 weight% with respect to resin.

  The thickness of the intermediate layer 14c is preferably 0.1 to 20 μm, and more preferably 0.3 to 3 μm.

  Further, the intermediate layer 14c and / or the protective layer 14d laminated on the reversible thermosensitive recording layer 14a preferably contains a resin having low oxygen permeability. Thereby, it becomes possible to suppress the oxidation of the leuco dye and the developer in the reversible thermosensitive recording layer 14a.

  An under layer may be provided between the reversible thermosensitive recording layer 14a and the base sheet 14b. Thereby, the coloring sensitivity of the reversible thermosensitive recording layer 14a and the adhesiveness between the reversible thermosensitive recording layer 14a and the base sheet 14b can be improved.

  Moreover, in order to color the reversible thermosensitive recording layer 14a using laser light, the reversible thermosensitive recording sheet may be provided with a photothermal conversion layer that absorbs laser light and converts light into heat.

  The back layer 14e is a surface of the base sheet 14b on which the reversible thermosensitive recording layer 14a is not provided in order to prevent curling due to resin shrinkage on the surface on which the reversible thermosensitive recording layer 14a is provided. Is provided.

  The back layer 14e can contain a resin cured by heat, ultraviolet rays, electron beams, etc., preferably using ultraviolet rays. Moreover, as what can be hardened | cured using a heat | fever, an ultraviolet-ray, an electron beam, etc., the thing similar to the above can be used and it can harden | cure similarly to the above. The back layer 14e is formed in the same manner as the reversible thermosensitive recording layer 14a. At this time, the back layer 14e is preferably applied so that the shrinkage balance between the side on which the reversible thermosensitive recording layer 14a is provided and the side on which the back layer 14e is provided is balanced. Thereby, the reversible thermosensitive recording sheet can be flattened after all the layers are applied.

  In addition to the resin, the back layer 14e can also contain an organic filler, an inorganic filler, a lubricant, a color pigment, an antistatic agent, an ultraviolet absorber, and the like. Examples of inorganic fillers include carbonates, silicates, metal oxides, sulfate compounds, and examples of organic fillers include silicone resins, cellulose resins, epoxy resins, nylon resins, phenol resins, polyurethane resins, urea resins, melamines. Examples thereof include resins, polyesters, polycarbonates, styrene resins, acrylic resins, polyethylene, formaldehyde resins, polymethyl methacrylate, and the like. Examples of the ultraviolet absorber include compounds having a salicylate structure, a cyanoacrylate structure, a benzotriazole structure, a benzophenone structure, and the like. Examples of the lubricant include synthetic waxes, vegetable waxes, animal waxes, higher alcohols, higher fatty acids, higher fatty acid esters, amides and the like.

  The thickness of the back layer 14e is preferably 0.1 to 10 μm.

  Furthermore, in order to prevent heat dissipation, a heat insulating layer such as an air layer may be provided on the reversible thermosensitive recording sheet.

  As the reversible thermosensitive recording sheet 14, 530BD, 430BD, 431FB (manufactured by Ricoh Co., Ltd.), TRCG99CS, TRCG99SS, TRCG99SH, TRCGAACS, TRCGGBBS (manufactured by Mitsubishi Paper Industries Co., Ltd.) can be used.

  FIG. 4 shows an example of a method for producing a reversible thermosensitive recording medium of the present invention. First, the base material sheet 11 having the adhesive layer 15 is supplied by the roller 41 a, and the surface of the inlet 12 that is intermittently supplied by the roller 41 b without the IC chip is bonded to the adhesive layer 15. At this time, the rollers 41a and 41b are pressurized to such an extent that the IC chip is not damaged. The core sheet 13 having the adhesive layer 16 is formed with through holes at intervals in which the IC chips of the inlet 12 adhered to the adhesive layer 15 are accommodated by the through hole forming means 42. Further, a reversible thermosensitive recording sheet 14 having an adhesive layer 17 is supplied, and has a base sheet 11 in which the inlet 12 is bonded to the adhesive layer 15 by rollers 43a and 43b, and an adhesive layer 16 in which a through hole is formed. The core sheet 13 and the reversible thermosensitive recording sheet 14 having the adhesive layer 17 are sequentially bonded. At this time, the rollers 43a and 43b are pressurized to such an extent that the IC chip is not damaged. Further, the three sheets are supplied so that the IC chip of the inlet 12 fits in the through hole of the core sheet 13. The three sheets are bonded and then cut to obtain the reversible thermosensitive recording medium of the present invention.

  In order to form an image using the reversible thermosensitive recording medium of the present invention, the image may be rapidly cooled after being heated to a color development temperature or higher. Specifically, for example, when heating with a thermal head or laser light for a short time, the reversible thermosensitive recording layer 14a locally rises in temperature, so that heat is immediately diffused and rapid cooling occurs, resulting in a colored state. On the other hand, in order to erase the image, it may be heated and cooled for a long time using a heat source, or may be temporarily heated to a temperature slightly lower than the coloring temperature. When heated for a long time, the temperature rises in a wide range of the reversible thermosensitive recording layer 14a, so that the subsequent cooling becomes slow and the color is erased. In this case, a heat roller, a heat stamp, hot air, or the like may be used as the heat source. Further, by adjusting the voltage applied to the thermal head and the pulse width, the applied energy may be slightly reduced from that during image formation. If this method is used, an image can be formed and erased with only a thermal head, and so-called overwriting becomes possible.

  FIG. 5 shows an example of a printer that forms and erases an image on the reversible thermosensitive recording medium of the present invention. In the printer shown in FIG. 5, the reversible thermosensitive recording medium 50 is conveyed in the direction of the arrow, and is discharged out of the system through the ceramic bar 51, the conveying roller 52, the thermal head 23, and the platen roll 54. In this case, the image is erased by the ceramic bar 51 and the image is formed by the thermal head 53 and the platen roll 54.

  FIG. 6 shows another example of a printer that forms and erases an image on the reversible thermosensitive recording medium of the present invention. In the printer shown in FIG. 6, the reversible thermosensitive recording medium 60 is conveyed in the direction of the arrow, and is discharged out of the system through the heat roll 61, the thermal head 62, the platen roll 63, and the conveyance roller 64. In this case, the image is erased by the heat roll 61 and the image is formed by the thermal head 62 and the platen roll 63.

  The conveyance speed of the reversible thermosensitive recording medium is set to, for example, 10 to 100 mm / sec. The conveyance speed at the time of image formation and erasure is adjusted by the inlet according to the thickness of the reversible thermosensitive recording sheet. Is done. For this reason, the reversible thermosensitive recording medium and the printer are configured so that the image formation and erasure are accurately performed by the heat treatment. In addition, when the printer is small, image formation and erasure are performed continuously. Therefore, the image is formed and erased accurately by adjusting the heating energy during the heat treatment. ing.

  Since the reversible thermosensitive recording medium of the present invention has both a reversible thermosensitive recording layer and an IC chip, information can be confirmed by displaying information written on the IC chip on the reversible thermosensitive recording layer, Convenience is improved. The reversible thermosensitive recording medium of the present invention was processed into general document sizes such as entrance / exit tickets, frozen food containers, industrial products, stickers for various chemical containers, logistics management applications, manufacturing process management, document management applications, etc. It can be widely used as a sheet.

(Examples 1-6, Reference Examples 7-10, Examples 11, 12, Reference Examples 13-16 )
Using the method shown in FIG. 4, a reversible thermosensitive recording medium in which an IC chip protrudes from the through hole of the core sheet 13 toward the reversible thermosensitive recording sheet 14 (see Table 1) was manufactured. The substrate sheet 11 is a white PET film having a thickness of 75 μm, the inlet 12 is a card-size inlet, the core sheet 13 is a 130 μm-thick water-resistant paper poem (manufactured by Kishu Paper Co., Ltd.), and the thickness is 125 μm. PET film Lumirror (Toray Industries, Inc.) (hereinafter referred to as PET film A), PET film Lumirror (Toray) (hereinafter referred to as PET film B) having a thickness of 188 μm, Kishu NIP (manufactured by Kishu Paper Co., Ltd.), 630BD 75 μm base as reversible thermosensitive recording sheet 14, and double-sided tape with a thickness of 20 μm as adhesive layers 15, 16 and 17 (core: none, adhesive: acrylic adhesive) ) Yellow Sepanone Support (manufactured by Toho Paper Industries Co., Ltd.) (hereinafter referred to as double-sided tape A), 140 μm thick double-sided tape (core: non-woven) , Adhesive: # 8180 of the acrylic pressure-sensitive adhesive) (manufactured by Dainippon Ink and Chemicals, Inc.) (hereinafter, was used) of double-sided tape B.

（比較例１、２）
粘着層１５、１６及び１７の代わりに、ホットメルト接着剤として、オレフィン系接着剤モレスコメルトＨＲ−１２Ｍ（松村石油研究所社製）を厚さが８５μｍとなるように手塗りで形成し、図４に示す方法において、加圧接着させる代わりに、ホットメルト接着させた以外は、上記実施例及び比較例と同様に、可逆性感熱記録媒体を製造した。
（印字品質）
可逆性感熱記録媒体を感熱プリンタＢ−４３０（東芝テック社製）を用いて、斜線１ドットの印字パターンで印字し、可逆性感熱記録媒体のＩＣチップ領域及びインレット領域の印字状態を目視で評価した。なお、印字抜けが無く、良好な画像であったものを○、ＩＣチップ部分が窪み、窪み部分で印字抜けが観察されたものを×１、ＩＣチップの周辺部において、印字抜けが観察されたものを×２、可逆性感熱記録媒体が反ると共に、印字ヘッドとの当たりが悪くなり、全面に印字カスレが観察されたものを×３として、判定した。
（耐水性）
水中に可逆性感熱記録媒体を３０分間浸漬させた後、可逆性感熱記録媒体の剥離性を評価し、剥離しなかったものを○、剥離したものを×として、判定した。
（評価結果）
表１より、ＩＣチップの突出が−５〜４５μｍ、コアシートとして、耐水紙又はＰＥＴフィルムを用い、粘着層として、両面テープを用いた実施例１〜１０の可逆性感熱記録媒体は、印字品質及び耐水性に優れることがわかる。なお、両面テープＡを用いると、ＩＣチップ領域の印字品質が更に向上し、両面テープＢを用いると、インレット領域の印字品質が更に向上する。両面テープＡは、芯材を有さず薄いため、印字時にＩＣチップ領域がプリンタヘッドに接触することができ、ＩＣチップ領域の印字品質が向上するものと考えられる。両面テープＢは、厚いため、印字時にＩＣチップ領域がプリンタヘッドに接触しにくくなり、ＩＣチップ領域の印字品質が低下するが、芯材の不織布にクッション性があるため、インレット領域の印字品質が向上するものと考えられる。

(Comparative Examples 1 and 2)
Instead of the adhesive layers 15, 16 and 17, as a hot melt adhesive, an olefin-based adhesive Morescommelt HR-12M (manufactured by Matsumura Oil Research Co., Ltd.) was formed by hand coating so as to have a thickness of 85 μm. A reversible thermosensitive recording medium was produced in the same manner as in the above Examples and Comparative Examples except that hot melt bonding was used instead of pressure bonding.
(Print quality)
Using a thermal printer B-430 (manufactured by TOSHIBA TEC), the reversible thermosensitive recording medium is printed with a 1-dot diagonal print pattern, and the printed state of the IC chip area and the inlet area of the reversible thermosensitive recording medium is visually evaluated. did. In addition, there was no printing omission and the image was a good image, ○, the IC chip portion was depressed, and x1 was observed where printing omission was observed in the depression, and printing omission was observed in the peripheral portion of the IC chip. The result was determined as x2, where the reversible thermosensitive recording medium warped and the contact with the print head worsened, and print blurring was observed on the entire surface as x3.
(water resistant)
After the reversible thermosensitive recording medium was immersed in water for 30 minutes, the peelability of the reversible thermosensitive recording medium was evaluated.
(Evaluation results)
From Table 1, the reversible thermosensitive recording media of Examples 1 to 10 in which the protrusion of the IC chip is −5 to 45 μm, the waterproof sheet or PET film is used as the core sheet, and the double-sided tape is used as the adhesive layer, the print quality And it turns out that it is excellent in water resistance. When double-sided tape A is used, the print quality of the IC chip area is further improved, and when double-sided tape B is used, the print quality of the inlet area is further improved. Since the double-sided tape A does not have a core material and is thin, the IC chip area can come into contact with the printer head during printing, and it is considered that the printing quality of the IC chip area is improved. Since the double-sided tape B is thick, the IC chip area is less likely to come into contact with the printer head during printing, and the print quality of the IC chip area deteriorates. However, the core nonwoven fabric has cushioning properties, so the print quality of the inlet area is low. It is thought to improve.

It is a figure which shows an example of the reversible thermosensitive recording medium of this invention. It is a figure which shows an example of the inlet used by this invention. It is a figure which shows an example of the reversible thermosensitive recording sheet used by this invention. It is a figure which shows an example of the manufacturing method of the reversible thermosensitive recording medium of this invention. It is a figure which shows an example of the printer used by this invention. It is a figure which shows the other example of the printer used by this invention. It is a figure which shows an example of the conventional IC card.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Base material sheet 12 Inlet 12a IC chip 12b Base material 13 Core sheet 14 Reversible thermosensitive recording sheet 14a Reversible thermosensitive recording layer 14b Base material sheet 15, 16, 17 Adhesive layer

Claims (7)

Substrate sheet, the inlet having an IC chip, a reversible thermosensitive recording sheet core sheet and the reversible thermosensitive recording layer through hole is formed are formed sequentially bonded through an adhesive layer and a reversible thermosensitive recording A medium,
Together with the IC chip through the through hole, and a surface on the side where the reversible thermosensitive recording layer of the reversible thermosensitive recording sheet is not formed is bonded so as to face the said core sheet,
The reversible thermosensitive recording medium , wherein the core sheet is paper having a layer containing a pigment and a synthetic rubber copolymer formed on both sides . The IC chip is reversible thermosensitive recording medium according to claim 1, characterized in that it is bonded so as to protrude the side to -5μm than 45μm below the reversible thermosensitive recording sheet from the through-hole.   The reversible thermosensitive recording medium according to claim 1, wherein the adhesive layer contains an acrylic resin. The synthetic rubber-based copolymer, a styrene - reversible thermosensitive recording medium according to any one of claims 1 to 3, wherein the butadiene-based copolymer.   The reversible thermosensitive recording medium according to claim 4, wherein the layer containing the pigment and the synthetic rubber copolymer further contains an acrylic copolymer. The reversible thermosensitive recording layer has a structural formula

(In the formula, X and Y are each independently a divalent organic group having a hetero atom , R ¹ is a substituted or unsubstituted divalent hydrocarbon group , and R ² is substituted or unsubstituted. a monovalent hydrocarbon group substituted, a is 1 to 3 an integer, b is 1 to 20 integer, c is is an integer of 0 to 3.)
And / or a structural formula represented by

(In the formula, Z is a divalent organic group having a hetero atom , R ³ is a substituted or unsubstituted divalent hydrocarbon group , and R ⁴ is a substituted or unsubstituted monovalent carbon group. A hydrogen group , and d is an integer of 1 or more and 3 or less.)
A reversible thermosensitive recording medium according to any one of claims 1 to 5, comprising a compound represented by the formula : and a leuco dye. The substrate sheet on which the adhesive layer is formed, the inlet having an IC chip, a reversible thermosensitive recording medium using a reversible thermosensitive recording sheet core sheet及beauty viscosity sealable layer of the adhesive layer is formed is formed a how you manufacture,
The reversible thermosensitive recording sheet has a reversible thermosensitive recording layer formed on the surface on which the adhesive layer is not formed,
The core sheet is paper in which layers containing a pigment and a synthetic rubber copolymer are formed on both sides,
Pressure bonding the surface of the inlet that does not have an IC chip to the base sheet;
Forming a through hole in the core sheet;
The substrate sheet to which the inlet is bonded, the core sheet having the through-hole formed therein, and the reversible thermosensitive recording sheet, and the IC chip penetrates the through-hole and the reversible feeling of the reversible thermosensitive recording sheet. A method for producing a reversible thermosensitive recording medium, comprising a step of sequentially pressing and adhering so that a surface on which a thermal recording layer is not formed faces the core sheet .

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