JP2009048026A - Display body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display body that is as flexible as paper, that hardly gets broken and wrinkled due to folding, with less environmental curling, also, that is repeatedly usable, and does not generate harmful gas upon incinerating after being used, with consideration to environment. <P>SOLUTION: The display body includes at least four layers, that is, a display layer 1, a base material 2 that supports the display layer, an adhesive layer 4 disposed on the side with no display layer of the base material, and a polyester elastomer sheet layer 3 bonded to the base material with the adhesive layer. The thickness of the adhesive layer 4 is 1 to 400 μm, the thickness ratio of the base material 2 to the polyester elastomer sheet layer 3 (polyester elastomer sheet/base material) is in the range of 2.5 to 10 or 0.5 to 1.5, and the glass transition temperature of the polyester elastomer constituting the polyester elastomer sheet layer is in the rage of 0 to 70°C, and the elastic modulus of the polyester elastomer is in the range of 100 to 1,000 MPa. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display body that is unlikely to be cracked or creased, has little environmental curl, and is flexible like paper that can incorporate an identification tag.

  In recent years, due to environmental concerns and increasing interest, when disposing of printed materials and process papers, including display media, not only simply discarding them, but also reusing them that can be used repeatedly, or those that can be separated as raw materials It has come to be separated and generated for reuse. Furthermore, even those that cannot be taken out as raw materials are reused by being burned as energy. However, when it is recycled as a raw material, it is rather expensive to separate and produce, and extra energy is required. On the other hand, at the time of incineration after use, environmental problems such as generation of harmful gases and damage to the incinerator are shortened.

  Therefore, in the display (media) body, if the display method is changed to the thermal rewrite method which can be rewritten many times, the life of the medium is extended and the environment becomes easy because it is used repeatedly. In card media in particular, there is a movement to replace a card material with a material such as polyester that does not contain chlorine, instead of polyvinyl chloride, which has been widely used in the past.

  For example, Patent Document 1 discloses a heat-resistant card with less curling while using a polyester material in consideration of the environment. In this technique, a high heat-resistant sheet layer such as polyester or polycarbonate is laminated on the front and back of an amorphous polyester having a glass transition point of 80 ° C. or higher so that it can withstand thermal deformation at 90 ° C. However, when amorphous polyester having a high glass transition temperature is used, although the rigidity of the entire card is increased and heat resistance is improved, the sheet layer becomes brittle, and there is a problem that cracks and creases are likely to occur. With this technology, the heat resistance and the rigidity of the card can be improved, but the display body does not have the feature of “softness like paper” that is required from the market on the other side.

  On the other hand, Patent Document 2 discloses a display body in which a rewritable display layer and a holding layer made of, for example, a polyester elastomer having a sufficiently lower elastic modulus than the display base material are combined. By using this technique, it is possible to obtain an environment-friendly display body that can be rewritten repeatedly without being broken or folded. However, there is no description about the structural design, and when a display body is obtained only by this technique, a so-called “thermal warp” or “environment curl” phenomenon of the display body warping easily occurs, and this problem is solved. Not reached.

The phenomenon called “thermal warping” and “environmental curl” is caused by the difference in the thermal expansion coefficient and elastic modulus of each layer material constituting the display body according to the change in the usage environment temperature of the display body. This is a phenomenon in which the end of the sheet warps (or curls), impairs the appearance, makes the printer feeding / discharging operation difficult in recording / display operations, and is not preferable in actual use. In the technique of the conventional patent document 2, since the layers having extremely different elastic moduli are combined, this environmental curl is easily generated.
JP 2001-71669 A (pages 1 to 3) JP 2004-226488 A (pages 1 to 3)

  Therefore, the present invention provides a display body that is less likely to be cracked or creased, has less environmental curl, can be used repeatedly, and is compliant with a supple environment such as paper.

The present invention includes the following inventions.
(1) At least four layers of a display layer, a base material supporting the display layer, an adhesive layer disposed on the side of the base material without the display layer, and a polyester elastomer sheet layer bonded to the base material by the adhesive layer The thickness of the adhesive layer is 1 μm to 400 μm, and the thickness ratio of the base material to the polyester elastomer sheet layer (polyester elastomer sheet layer / base material) is 2.5 to 10 or 0. Display in which the glass transition temperature of the polyester elastomer constituting the polyester elastomer sheet layer is in the range of 0 to 70 ° C. and the elastic modulus is in the range of 100 to 1000 MPa. body.
(2) The display body according to (1), wherein the adhesive layer for bonding the base material and the polyester elastomer sheet layer has an elastic modulus of 10 to 500 MPa.
(3) The display according to (1) or (2), wherein the substrate is biaxially stretched polyethylene terephthalate.
(4) The display body according to any one of (1) to (3), wherein the display layer is a thermolite recording type thermal recording layer.
(5) The display according to any one of (1) to (4), wherein an electronic tag is held in an adhesive layer.

  The display body of the present invention does not generate cracks or wrinkles even when it is bent, and has the effect that it is as flexible as paper and at the same time has little curling (warping) against changes in environmental temperature. Further, by using a display layer using a rewritable recording method, it is possible to repeatedly rewrite and extend the life of the media, so that there is also an effect that it is environmentally friendly.

  FIG. 1 is a cross-sectional view of an example of a display body of the present invention. As can be seen from FIG. 1, the display of the present invention includes a display layer 1, a base material 2 that supports the display layer 1, a polyester elastomer sheet layer 3 that is bonded and combined with the base material 2, and a base material 2 and a polyester elastomer. It is mainly composed of an adhesive layer 4 that joins the sheet layer 3.

  As the display layer 1, various display layers such as thermal recording, pressure sensitive recording, thermal transfer recording, and ink jet recording can be selected. In particular, thermal recording is preferable as a display layer because it is suitable for uses such as delivery slips, process management tables, IC cards and IC tags because the printer device is simple and easy to carry. As for the combination of the color former and the color former in the heat-sensitive recording layer, any combination can be used as long as they react to cause coloration. In the case of a heat-sensitive recording layer, it is preferable to form an overcoat layer in order to protect the recording. Further, the display layer includes a multi-color thermal recording layer capable of performing thermal recording with two or more colors and a thermolite recording layer capable of repeated printing such as a reversible type thermal recording layer. Among them, the rewritable method is preferable from the viewpoint of environmental consideration because it can be used repeatedly and the life of the media is extended. Other rewritable recording methods that can be used include generally known rewritable display layers such as a display method using a thermosensitive dye, a polymer, or magnetic particles.

As a representative of the thermolite recording layer, a leuco-type thermal rewritable paper (for example, a patent) formed on a polyethylene terephthalate (PET) film as a polyester base material 2 by melting and mixing a leuco dye and a reversible developer. Reference 3). In this method, after heat is applied to the recording portion, the color is rapidly cooled to develop a color. On the other hand, when the color is to be erased, the display is controlled by slow cooling.
JP-A-10-203016 (pages 1 to 4)

  Another rewritable recording method includes electronic paper, for example. Electronic paper uses agglomeration / diffusion of charged particles in microcapsules, displays by moving or rotating spheres divided into two colors, and packs liquid crystals in microscopic holes in a polymer material. There are known so-called polymer dispersed liquid crystals, electrochromism, or magnetic recording devices that rotate and move magnetically controlled fine particles.

  A display layer using a rewritable recording method represented by the above can be used without limitation, but there are also layers that are weak against bending or the like due to the layer structure. Among these, a reversible type thermal recording method, a polymer A thermolite recording layer using a thermolite method, etc. can be used more preferably because it has a simple structure and is essentially resistant to bending.

As the material of the substrate 2, a polyester resin is preferably used in the present invention. As the polyester-based resin, for example, commercially available polyester resins such as polybutylene terephthalate such as polyethylene terephthalate and modified polyethylene terephthalate (commercialized as PET-G) can be used without limitation. The base material 2 is a film mainly composed of a single resin, a composite or a copolymer of these materials, a foamed film obtained by blending the resin with a foaming agent and foamed, and an inorganic pigment or an organic pigment added to the resin. Examples include films such as porous films in which voids are formed by blending and the like, synthetic papers and nonwoven fabrics, and laminated sheets obtained by bonding these. In the present invention, in particular, a biaxially stretched film of polyethylene terephthalate is most preferable from the viewpoints of high sensitivity and heat resistance during thermal recording.
The thickness is 10 μm to 200 μm, and preferably 30 μm to 150 μm. The polyester base material preferably used for the base material 2 generally has a larger elastic modulus than the polyester elastomer layer 3. Therefore, although depending on the thickness of the entire display body, when the thickness of the base material 2 exceeds 200 μm, the rigidity of the display body increases and the flexibility of paper disappears, and the cracking / folding phenomenon occurs. It is also not preferable because it is likely to occur.

  As the polyester elastomer constituting the polyester elastomer sheet layer 3, a commercially available polyester elastomer can be used without limitation. For example, a hard segment of an aromatic polyester such as tetramethylene terephthalate or polybutylene terephthalate, an aliphatic polyether, etc. The block copolymer comprised from these soft segments is mentioned. Further, when the elastomer is a polyester block copolymer of polyester composed of polyethylene terephthalate as a hard segment and dicarboxylic acids and diols as a soft segment, it is possible to obtain an elastic body having a small residual elongation after elongation.

  Furthermore, it is preferable that the glass transition temperature of the polyester elastomer which comprises a polyester elastomer sheet layer is 0-70 degreeC. Although the glass transition temperature tends to increase the flexibility of the sheet as the glass transition temperature is lower, the glass transition temperature lower than 0 ° C. is not practically preferable because the glass transition temperature that is too low decreases the heat resistance of the entire display body. On the other hand, when the glass transition temperature exceeds 70 ° C., the rigidity of the display body is increased, the flexibility such as that of paper is lost, and there is a concern that the phenomenon of cracking / folding may occur.

  The glass transition temperature according to the present invention can be easily measured without any limitation by a generally known thermal analysis method. For example, a method using a differential scanning calorimeter (DSC), a method using dynamic viscoelasticity measurement (DMA), a method using thermo-mechanical measurement (TMA), a method using specific volume-temperature change measurement using a dilatometer, and thermal diffusion The method of investigating temperature changes such as the rate, heat content, dielectric constant, and refractive index can also be mentioned.

  In the examination of the present invention, a dynamic viscoelasticity measurement (DMA) method, which is one of relatively simple methods, was adopted. For measurement, a dynamic viscoelasticity measuring device DMA6100 manufactured by SII Nano Technology Co., Ltd. is used, and in the tensile measurement mode, the MD (flow) direction of the sheet is set as the longitudinal direction, the static load is 0.04 MPa, the applied strain is The temperature change of the storage elastic modulus and loss tangent tan δ was recorded under the conditions of 0.33%, frequency 1 Hz, temperature increase rate 2 ° C./min, and the peak temperature of loss tangent tan δ was evaluated as the glass transition temperature.

  Furthermore, the elastic modulus of the polyester elastomer constituting the polyester elastomer sheet layer is preferably 100 to 1000 MPa, and more preferably 150 to 600 MPa. If the elastic modulus exceeds 1000 MPa, the paper is not flexible, and there is a concern that a crease or crease phenomenon may occur. On the other hand, when the elastic modulus is lower than 100 Pa, the sheet becomes too soft and the display body becomes soft, but the extreme softness makes it easier to generate environmental curls, which is not suitable for practical use.

The elastic modulus in the above range and the elastic behavior unique to the elastomer, and the glass transition temperature in the range according to the present invention are the optimal range that prevents cracking and crease and does not make the sheet too soft, and is flexible like paper. A gentle texture can be expressed.
The method of measuring the elastic modulus of the polyester elastomer sheet is determined by mechanical property tests such as a tensile test, a compression test, a bending test, etc. according to JIS-K7127: 1999 or JIS-K7181: 1994, There is no particular limitation on the measuring instrument. Moreover, you may use the storage elastic modulus calculated | required by the dynamic mechanical measurement (dynamic viscoelasticity measurement) according to JIS-K7244: 1999.

  In the examination of the present invention, a method by dynamic viscoelasticity measurement according to the above JIS-K7244-4: 1999 was adopted. The measurement was performed under the same conditions as the evaluation of the glass transition temperature described above. That is, using a dynamic viscoelasticity measuring machine DMA6100 manufactured by SII Nano Technology, the sheet is chucked with the MD (flow) direction as the longitudinal direction in a tensile measurement mode, a static load of 0.04 MPa, an applied strain of 0. The storage elastic modulus was recorded under the conditions of 33%, frequency 1 Hz, temperature increase rate 2 ° C./min, and the storage elastic modulus at room temperature (25 ° C.) was defined as the elastic modulus of the polyester elastomer sheet.

  In general, in an amorphous polymer material, the elastic modulus and the glass transition temperature have some correlation, but needless to say, the glass transition temperature is not necessarily uniquely determined by the elastic modulus. . However, in the present invention, both the elastic modulus and glass transition temperature ranges according to the present invention are satisfied at the same time in order to prevent cracks and creases and to express a supple texture like paper more effectively. Is highly preferred.

  The thickness of the polyester elastomer sheet layer 3 is determined by the thickness ratio with the polyester display substrate 2. The thickness ratio (polyester elastomer sheet layer 3 thickness / polyester substrate 2 thickness) ratio is in the range of either (1) 2.5 to 10 or (2) 0.5 to 1.5. If the thickness ratio is outside this range, so-called “environmental curling” occurs violently, which is not preferable in practice.

  Sheets made by laminating a low modulus elastomer (back layer) and a highly elastic polyester-based display substrate (surface layer) as in the present invention have different in-layer stresses on the front and back layers due to temperature changes. In other words, the phenomenon of so-called “thermal warping” and “environmental curling” that the end of the display body warps up (or curls) easily occurs. Such a curl phenomenon not only impairs the appearance but also makes it difficult to supply and discharge the printer in the recording / display operation, which is extremely undesirable in actual use.

However, if it is within the range of the thickness ratio of the layers according to the present invention described above, the stress balance in the front and back layers is balanced, the occurrence of warpage is suppressed, and it is reduced to a range where there is no practical problem.
There are two thickness ratio ranges (1) 2.5 to 10 and (2) 0.5 to 1.5 as described above. In the case of the layer structure according to the invention, the present invention is also characterized based on the fact that there are two places.

  As long as the effects of the present invention are not impaired, any thickness ratio range of (1) to (2) may be used, but it prevents cracking / folding and expresses a supple texture like paper. If importance is attached, the thickness of the polyester elastomer sheet layer 3 becomes thicker. The range of polyester elastomer sheet 3 thickness / polyester substrate 2 thickness = 2.5 to 10 is more preferable.

The adhesive layer 4 is used to join the polyester base 2 and the polyester elastomer sheet layer 3 together. The adhesive layer 4 is formed by sandwiching a thermoplastic film between the polyester substrate 2 and the polyester elastomer sheet layer 3 and heating, or applying an adhesive. Such a bonding process may be performed independently or separated into several processes.
As an adhesive used for the adhesive layer 4 of the present invention, a so-called thermoplastic film, an adhesive, and a commercially available product called an adhesive can be used without any limitation, but when these materials form an adhesive layer, The elastic modulus is preferably 10 to 500 MPa. More preferably, it is 10-200 MPa.

  The elastic modulus of the adhesive layer affects the phenomenon of anti-folding / folding resistance, suppleness and environmental curl. The elastic modulus of the adhesive is as low as possible, and closer to that of the polyester elastomer sheet layer is better than the high elastic modulus of the polyester base material. In the case of the elastic modulus range according to the present invention, the in-layer stress of the adhesive layer located in the “intermediate” layer can be substantially ignored with respect to the “curl” without impairing the “flexibility”. Therefore, the improvement of environmental curl can be controlled by the polyester base (front) and the polyester elastomer sheet layer (back) which are the “front” and “back” layers.

  On the other hand, when the elastic modulus of the adhesive layer exceeds 500 MPa, it becomes close to that of the polyester base material, the rigidity of the entire display body is increased, and it is extremely unsuitable for improvement of cracks / folds and expression of flexibility. Accordingly, as described above, the elastic modulus of the adhesive layer is preferably low. However, if the elastic modulus is lower than 10 MPa, it is too soft, and there is a concern that a layer cannot be formed as a structure. .

Thus, in the present invention, in order to solve the conflicting problems of crack resistance, crease resistance, flexibility and environmental curl reduction at the same time, a polyester base material and a polyester having a specific range of glass transition temperature and elastic modulus It has been proposed that the polyester elastomer sheet layer composed of elastomer can be effectively formed by controlling the layer thickness ratio to a specific ratio. In order to make it even more effective, it is an extremely important requirement that the elastic modulus of the adhesive layer be within the range according to the present invention as described above.
Furthermore, since the polyester base material and the polyester elastomer sheet layer are the main constituent elements, there is little generation of toxic gas when discarded by incineration. In addition, the use of polyester-based materials that are easy to recover as raw materials has little impact on the environment.

  It is considered that the adhesive layer having an elastic modulus according to the present invention only needs to work as an intermediate layer only for the purpose of joining both the polyester base material and the polyester elastomer sheet layer. In this case, the thickness of the adhesive layer may be about 1 μm to 400 μm, and preferably 2 μm to 300 μm.

  Examples of materials for adhesives, pressure-sensitive adhesives, and thermoplastic films are mainly vinyl acetate resins, vinyl chloride resins, acrylic resins, olefin resins, diene resins, natural rubber, gelatin, glue, abietin resins, and cellulose derivative resins. , Polyester resins, modified polyester resins, epoxy resins, vinyl butyral resins, urethane resins, polyamide resins, alkyd resins, melamine resins, urea resins, phenol formalin resins, petroleum resins, maleic acid copolymers, etc. There are a single, a mixture, a copolymer, and the like.

  Materials to be added to the thermoplastic film or adhesive or pressure-sensitive adhesive include dispersants, thickeners, fats and oils, crosslinking agents, curing agents, plasticizers, release agents, antioxidants, stabilizers, UV absorbers, stilts, Foamed particles, conductive agents, fiber fillers, rubber-like particles, colored pigments, opacifying materials, catalysts, and the like are appropriately used within the range where the insulating properties are not impaired.

  You may add a hardening | curing agent within the range in which adhesion | attachment is possible. For example, there are an epoxy resin, an isocyanate compound, a metal crosslinking agent, and the like. The cross-linking reaction proceeds after pasting due to moisture in the air, and moisture curing type isocyanate group-containing urethane resin, etc. obtained by delaying the required hardness in time, provides sufficient fluidity for adhesion, It is preferably used because it can be cured over time to obtain the required strength. Also, a method of partially spraying a curing agent and reinforcing only a specific portion may be used.

These may be used alone or as a mixture, and hot melt coating, water-based or solvent-based coating may be performed, and if necessary, hot air drying may be performed to obtain a film-like thermoplastic film. The coating amount is usually about 1 to 500 g / m ² in terms of dry weight, although it depends on the final total thickness of the target display body and the thickness of the adhesive layer targeted for design.

  If the adhesive layer is made as thin as possible and the adhesive material is selected from polyethylene or polyester, the entire display body can be reused as a chemical raw material, and the environment can be considered.

  Also, RFID (Radio Frequency Identification) tags using IC using the adhesive layer 4 and identification used for theft prevention using EAS (Electronic Article Surveillance) technology. Tags, which are collectively referred to simply as electronic tags, can be integrated with the display body of the present invention. An insulating sheet on which electronic parts such as an antenna and an IC are mounted is generally called an inlet as a whole. For example, the inlet is embedded in an adhesive layer, or an adhesive is applied to the front and back surfaces of a display body. The display body can be an “RFID tag” or an “identification tag”, for example, by using layers.

  As a general manufacturing method of the inlet, a method of attaching a coil made of a wire such as silver or copper to an insulating sheet having a thickness of 20 to 100 μm made of a resin such as polyethylene terephthalate, glycol-modified polyester, polypropylene, or polyethylene. , A method of etching copper or aluminum into a coil shape, a coiled antenna printed in a coil shape using a conductive ink or the like, a conductive ink on an insulating sheet made of resin or paper such as polyethylene terephthalate, polypropylene, polyethylene, etc. For example, a plate antenna or the like on which metal such as copper or aluminum is deposited can be used. Further, various IC chips are mounted as data storage and / or calculation units on the antenna. In addition, it is also possible to arrange a capacitor or the like as appropriate. Of these, a communicable system equipped with an IC chip is read as RFID, and individual product information and distribution information can be conveyed. As such an inlet, what is marketed as SRF55V10P square inlay (dimensions of 48 mm x 48 mm) manufactured by Infineon Co., Ltd. may be mentioned. When such an inlet is actually embedded in an adhesive layer and used as a display body, it is necessary to configure so that the crease avoids the IC chip on the inlet in the case of evaluation of folds as described later. is there.

  In the case of such a display body having a built-in electronic tag, more accurate display can be performed by removing the RFID portion from the actual display / printing range. In general, RFID has many highly elastic components such as antennas and insulating sheets, so even if the display range is not removed from that part, the display function is not significantly impaired and simple display performance is demonstrated. It can be done.

  Since the total thickness of the entire display body depends on the use of the display body, there is no particular limitation as long as the effects of the present invention such as suppleness are not impaired, but generally it is about 100 μm to 2000 μm, preferably It is about 200 μm to 1000 μm.

  Next, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

[Measurement method of characteristic value and evaluation method of effect]
The characteristic value measurement method and the effect evaluation method in the examples are as follows.
(1) Layer thickness measurement of each layer The polyester base material, the polyester elastomer sheet, the adhesive layer, and the thickness of each layer were measured using a micrometer according to JIS-K7130: 1999, Method A. The thickness of the adhesive layer was determined by subtracting the thickness of the display layer + polyester substrate and the thickness of the polyester elastomer sheet from the thickness of the entire display body.

(2) Dynamic Viscoelasticity Measurement Evaluation of the glass transition point and elastic modulus of the polyester elastomer sheet and evaluation of the elastic modulus of the adhesive layer were performed by dynamic viscoelasticity measurement. A dynamic viscoelasticity measuring device DMA6100 manufactured by SII Nano Technology was used as the dynamic viscoelasticity device. A polyester elastomer sheet or a solidified adhesive sheet is cut into a strip shape with a width of 10 mm and a length of 40 mm with the MD (flow) direction of the sheet as the longitudinal direction. In the tensile measurement mode, the distance between chucks is 20 mm, static load The temperature change of the storage elastic modulus and loss tangent tan δ was recorded under the conditions of 0.04 MPa, applied strain of 0.33%, frequency of 1 Hz, and heating rate of 2 ° C./min. The storage elastic modulus at 25 ° C. of the adhesive sheet and the polyester elastomer sheet is the elastic modulus of the adhesive layer and the polyester elastomer sheet layer, respectively, and the peak temperature of the loss tangent tan δ of the polyester elastomer sheet is the glass transition temperature of the polyester elastomer sheet layer. And evaluated.

(3) Evaluation of crease and suppleness The crease was evaluated by the following operation. First, fold the display body into a parallel press device so that there are no creases, press the press plate so that the distance between the press plates is twice the thickness of the display body, immediately release the pressure, Let stand for 1 hour. Sensory evaluation was performed on the state of the crease when it was bent. In addition, the degree of “flexibility” of the display body was also subjected to sensory evaluation. The supple state without any creases was evaluated as “◯”, the supple but creased with “△”, and the supple and notched creased with “×”.

(4) Evaluation of environmental curl The display body is left on the desk for 2 hours or more in the environmental test room (built-in chamber TBR3N1CR, manufactured by Tabai Espec Co., Ltd.) under the specified temperature and humidity conditions, and the warping of the end face is carried out on the desk surface. It was evaluated by the height from. Measure warp height at standard temperature and humidity (25 ° C, 50% RH) and warp height at low temperature (5 ° C, 50% RH), and change amount of warp (warp amount when temperature change is 20 ° C) ) Was used for evaluation of environmental curl. The case where the amount of warpage change was 5 mm or less was evaluated as “◯”, the case where the amount of warpage was 5 to 10 mm was evaluated as “Δ”, and the case where 10 mm or more was evaluated as “×”.

[Example 1]
The display body shown in FIG. 1 was created. Rewrite film TFR85W made by Mitsubishi Paper Industries, which hits the base material 2 and the display layer 1 (a 75 μm thick polyethylene terephthalate film corresponding to the base material 2 was provided with a thermoreversible thermosensitive paint layer serving as the display layer 1 in a thickness of 10 μm. 1), a polyester elastomer sheet layer 3 having a thickness of 300 μm, Nobellan P4135AN manufactured by Teijin Chemicals Limited, and an adhesive manufactured by Toyo Morton Co., Ltd. (main agent AD-577, curing agent 10L mixed in 5: 1) Was used, and the thickness of the adhesive layer 4 was 10 μm. This sample was cut into a size of 10 cm × 10 cm to produce a display.

[Example 2]
In Example 1, instead of TFR85W, which corresponds to the base material and the display layer, a rewrite film TRF60W manufactured by Mitsubishi Paper Industries Co., Ltd. (a 50 μm thick polyethylene terephthalate film provided with a 10 μm thermoreversible thermosensitive paint layer) was used. A display was produced in the same manner as in Example 1.

[Example 3]
In Example 2, instead of the adhesive made by Toyo Morton (a mixture of the main agent D-577 and the curing agent 10L in a ratio of 5: 1) as the bonded adhesive, Cemedine EP-001 (elastic epoxy) manufactured by Cemedine A display body was prepared in the same manner as in Example 2 except that the adhesive layer was used and the thickness of the adhesive layer was 300 μm.

[Example 4]
In Example 3, a display body was prepared in the same manner as in Example 3 except that 300 μm thick Hytrel 2551 manufactured by Toray DuPont was used instead of Tiber Chemical's Nouvelan P4135AN.

[Example 5]
In Example 1, a display body was prepared in the same manner as in Example 1 except that a sheet having a thickness of 100 μm was used instead of the sheet having a thickness of 300 μm of Nobellan P4135AN manufactured by Teijin Chemicals Ltd. which is a polyester elastomer sheet layer.

[Comparative Example 1]
In Example 1, instead of TFR85W which hits the base material and the display layer, a rewrite film TRF135W manufactured by Mitsubishi Paper Industries Co., Ltd. (a polyethylene terephthalate film having a thickness of 125 μm provided with a thermoreversible thermosensitive paint layer of 10 μm), a polyester elastomer A display body was produced in the same manner as in Example 1 except that the thickness of Nobellan P4135AN manufactured by Teijin Chemicals Ltd., which is a sheet layer, was 250 μm.

[Comparative Example 2]
In Example 3, instead of Cemedine EP-001 (Elastic Epoxy Adhesive) manufactured by Cemedine, which is a bonded adhesive, Cemedine High Super 5 (Normal Temperature Curing Epoxy Adhesive) manufactured by Cemedine is used, and the thickness of the adhesive layer is used. A display was prepared in the same manner as in Example 3 except that the film was bonded at 450 μm.

[Comparative Example 3]
In Example 1, a display body was prepared in the same manner as in Example 1 except that 300 μm thick Hytrel 2751 made by Toray DuPont was used instead of Tiber Chemicals Nouvelan P4135AN which is a polyester elastomer sheet layer. .

[Comparative Example 4]
In Example 1, a display body was prepared in the same manner as in Example 1 except that Hytrel 4057 made by Toray DuPont having a thickness of 300 μm was used instead of Nobellan P4135AN made by Teijin Chemicals, which is a polyester elastomer.
Table 1 summarizes the characteristic values and evaluations of the above examples.

As is apparent from Examples 1 to 5, the display body having the ratio of polyester elastomer sheet layer thickness / polyester base material layer thickness according to the present invention is a conflicting problem of anti-cracking / folding, flexibility, and environmental curl reduction. It was found that can be solved simultaneously. Furthermore, it turned out that performance can be improved more effectively by adjusting the elasticity modulus and adhesive layer thickness of an adhesive layer to a specific range (Examples 1-3). Moreover, as long as the elastic modulus and glass transition point of the polyester elastomer constituting the polyester elastomer sheet layer were within a specific range, the effect was not changed compared to Example 3 even if the type of the polyester elastomer was changed (implementation). Example 4).
On the other hand, even if each layer has the same material and configuration as in Comparative Example 1, if the ratio of the thickness of the polyester elastomer sheet / the thickness of the polyester base material is outside the range of the present invention, the environmental curl deteriorated. On the other hand, when the thickness of the adhesive layer was outside the range of the present invention, the anti-cracking / folding and suppleness deteriorated on the contrary, and it was impossible to achieve both characteristics (Comparative Example 2).
Furthermore, when the elastic modulus of the polyester elastomer which comprises a polyester elastomer sheet layer, and a glass transition point remove | deviate from a specific range, it turned out that an effective effect is not acquired (comparative examples 3 and 4).

The display body of the present invention is a supple display body such as paper that is less likely to be broken and creased and has less environmental curl. Further, by providing a rewritable recording layer, it can be used repeatedly, and since it does not generate harmful gases when incinerated after being used, it is suitable as an environmentally friendly display. Further, by incorporating an IC chip or the like, it can be suitably used as an electronic tag.

Sectional drawing of an example of the display body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display layer 2 Base material 3 Polyester elastomer sheet layer 4 Adhesive layer

Claims (5)

  A display body comprising at least four layers of a display layer, a base material supporting the display layer, an adhesive layer disposed on the side of the base material without the display layer, and a polyester elastomer sheet layer bonded to the base material by the adhesive layer The thickness of the adhesive layer is 1 μm to 400 μm, and the thickness ratio of the base material to the polyester elastomer sheet layer (polyester elastomer sheet layer / base material) is 2.5 to 10 or 0.5 to The display body which is in the range of 1.5, the glass transition temperature of the polyester elastomer constituting the polyester elastomer sheet layer is in the range of 0 to 70 ° C., and the elastic modulus is in the range of 100 to 1000 MPa.   The display body according to claim 1, wherein the adhesive layer has an elastic modulus of 10 to 500 MPa.   The display body according to claim 1, wherein the base material is biaxially stretched polyethylene terephthalate.   The display body according to claim 1, wherein the display layer is a thermolite recording layer.   The display body according to claim 1, wherein an electronic tag is held in the adhesive layer.

Images