JP2789660B2 - Information record display card - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording and display card such as an optical card, an IC card, and a magnetic card, and more particularly to an information recording apparatus provided with a visible information display section. It relates to a display card.

[Summary of the Invention] The present invention relates to information recorded on an optical card, an IC card, a magnetic card, or the like, or information based on the content recorded in a card reader / writer or a storage device connected thereto. In an information recording and display card for reversibly displaying and erasing a visible information display portion using a phase transition mode by heating, by laminating an undercoat layer and an overcoat layer as a protective film layer on the visible information display portion, An object of the present invention is to prevent a visible information display portion from being damaged at the time of writing by a thermal head or the like, and to secure a high contrast ratio at the same time.

[Conventional technology]

At present, which is said to be the age of cards, many types of information recording cards, mainly magnetic cards, are used. For example, in addition to the above-mentioned magnetic card, an IC card, an optical card, and the like are also used. These cards have a much larger storage capacity than a magnetic card, and are expected as next-generation cards having more advanced functions.

However, the information recorded on these information recording cards cannot be checked directly by visual observation, regardless of whether the information is recorded on a magnetic card, an IC card, or an optical card. Therefore, if the information recorded on the card or a part of the information is displayed on the card in a state that can be directly viewed, it becomes very convenient for the user. For example,
If the payment date and amount are displayed for a credit card, the balance of an account is displayed for a cash card, and the available balance and expiration date are displayed for a prepaid card, the card performs more advanced functions and benefits the user.

In order to achieve this object, conventionally, there have been proposed an embossing method in which characters are directly pressed against a plastic card substrate to form irregularities, and a method of printing on the surface of the card substrate with a printer each time it is used.

However, with these methods, once displayed information cannot be deleted, the display area is limited,
When printing is performed for a predetermined number of lines, the display function of the card is lost, and the card must be replaced with a new card.

Therefore, an information recording / display card has been proposed that has a simple structure that does not require a built-in power supply, a driving electrode, a polarizing plate, etc., and that can reversibly display and erase visible information such as characters, numerals, and figures with high reliability. ing.

For example, an invisible information recording unit and a polymer nematic having an isotropic phase transition temperature (clearing point) higher than the glass transition temperature for visually displaying information based on the content recorded in the invisible information recording unit. The present applicant has already proposed an information recording / display card configured by arranging a rewritable visible information display unit mainly composed of liquid crystal on a card base.

In this information recording / display card, information based on the content recorded in the invisible information recording unit is transmitted by heat supplied by a thermal head built in the card reader / writer, or by light irradiation of flash light through a negative type mask, for example. Thus, the information is written in the visible information display section provided on the card substrate, and characters, numerals, figures, and the like are displayed in a visible state. The written characters and the like are erased by annealing by heat or light irradiation, and display and erasure can be performed reversibly and repeatedly.

[Problems to be solved by the invention]

However, in the information recording / display card provided with the visible information display unit using the phase transition mode by heating as described above, the visible information display unit may be damaged or cracked when writing or erasing with the thermal head. However, there is a disadvantage that it cannot be used repeatedly many times. Therefore, it is desired that these drawbacks be promptly improved.

Therefore, the present invention has been proposed in view of such a conventional situation, and prevents damage to a visible information display portion which occurs at the time of writing and erasing, secures a high contrast ratio at the same time, and is used repeatedly many times. It is an object of the present invention to provide a possible information record display card.

[Means for solving the problem]

The present invention has been proposed to achieve the above object, and an information recording and display card having a visible information display section using a phase transition mode by heating a polymer material in at least one of recording and erasing is provided. An undercoat layer made of an elastomeric material and an overcoat layer made of a material having excellent heat resistance are sequentially laminated on the visible information display portion.

The overcoat layer serves as a protective film for preventing the visible information display portion from being damaged when writing and erasing by a thermal head or the like. Therefore, a film made of a material having excellent heat resistance is desirable. Examples of such a film include a film made of an ultraviolet curable resin, a film containing silica fine powder, a silica coating film coated by a sol-gel method, and a paraxylylene polymer film. These may be used alone or in combination.

On the other hand, the undercoat layer functions as a stress relieving material for preventing cracks generated at the time of erasing, and has a function of simultaneously improving the contrast ratio. As a material satisfying such a requirement, a film made of an elastomer material such as urethane is preferable.

In addition, since the undercoat layer and the overcoat layer are laminated in this order on the visible information display section, particularly when erasing from the visible information display section side with a thermal head or the like, the visible and erasable information is written and erased. The information display portion can be prevented from being damaged, the undercoat layer can be protected, and the contrast ratio can be secured.

For the visible information display portion, a polymer material whose optical properties such as transmittance and reflectance change due to phase transition by heating can be applied. Examples of such a polymer material include a polymer nematic liquid crystal having an isotropic phase transition temperature higher than a glass transition temperature. When the polymer nematic liquid crystal is heated to the isotropic phase transition temperature and then slowly annealed, small liquid crystal domains are generated and appear to be cloudy. Then, when the temperature of the cloudy and opaque state is raised using a thermal head or a laser beam or the like, the portion becomes transparent beyond the glass transition temperature, and writing of information such as characters and figures becomes possible.

Further, as the polymer material, a smectic polymer liquid crystal in which a cyanobiphenyl-based or phenylester-based mesogen is introduced into a polymethylsiloxane side chain can be used, and further, a main-chain cholesteric liquid crystal or polymethylsiloxane can be used. Cholesteric polymer liquid crystals into which siloxane side chains, phenylbenzoate groups and cholesterol derivatives have been introduced can also be used.

The main-chain cholesteric liquid crystal can be changed from a polydomain state to a monodomain or a laminated structure close to the monodomain by heating and melting in a liquid crystal formation temperature region. By rapidly cooling from this state to a crystallization temperature or lower (or a glass transition temperature or lower in the case of no crystallization), a monodomain state can be maintained at room temperature. Here, the polydomain is a state in which cholesteric liquid crystals in a microcrystalline state are aggregated, the direction of the helical axis of the cholesteric liquid crystal is not constant, and light is scattered at a crystal interface to give an opaque film. In contrast, a monodomain or a laminated structure close to a monodomain is a state in which cholesteric liquid crystals in a microcrystalline state match in a heated and melted state, and eventually the entire surface of the film has a laminated structure close to a single crystal. Good, the helical axis is perpendicular to the film surface and looks transparent, colored or colorless.

On the other hand, a cholesteric polymer liquid crystal in which a phenylbenzoate group and a cholesterol derivative are introduced into the side chain of polymethylsiloxane has a helical arrangement and exhibits the above-described optical characteristics unique to cholesteric, similarly to the above-mentioned main-chain cholesteric liquid crystal. That is, when the cholesteric polymer liquid crystal is rapidly heated by irradiation with a laser beam, a color change (a change in transmittance) occurs due to a change in the selective reflection wavelength corresponding to a change in the helical pitch length or a change in the rotation of the helical axis, and When the color is rapidly cooled by removing the irradiation with light, the color change state is preserved. On the other hand, when gradually cooled, the color change state disappears and returns to the original state.

As described above, the polymer material used for such a visible information display portion may be any of nematic and smectic cholesteric.

Further, in addition to these liquid crystals, for example, a mixture of two or more kinds of polymers combined to form a polymer system having a so-called phase diagram having a temperature region that becomes a compatible system and a temperature region that undergoes phase separation, or such a mixture. A block containing a polymer component forming a phase diagram as a component thereof, or a graft copolymer may be used.

In order to perform recording / reading using such a material, for example, when the polymer system is formed into a plate shape and a polymer system having a lower critical solution temperature is used, the temperature is lower than the cloud point, preferably the cloud point. Treat at a temperature in the range of 5 ° C below the glass transition point of the compatible polymer to make the whole compatible. When recording, locally heat with laser light, high frequency, etc. to cause phase separation and then quench. To fix the phase separation state.

Further, in the case of a polymer system having an upper critical solution temperature, the whole is subjected to a temperature of 5 ° C. or lower below the cloud point, preferably 5 ° C. below the glass transition point of the polymer forming a continuous phase with the cloud point, to bring the entire phase into a state of phase separation, At the time of recording, the temperature is locally raised to the cloud point or higher to make a compatible system and then rapidly cooled. The quenching is performed by rapidly cooling the glass forming temperature of the compatible system or the polymer forming the continuous phase upon separation to 5 ° C or lower, preferably 10 ° C or lower. Reading can be performed by measuring transmitted light or scattered light by applying a laser beam or the like.

In addition, a photochromic material can also be used. Photochromic materials develop color when irradiated with light,
When heated using a thermal head or the like, the color disappears. Recording and erasing of information can be performed using this principle.

[Action]

According to the information recording / display card of the present invention, since the overcoat layer made of a material having excellent heat resistance is laminated on the visible information display portion, the visible information display can be performed even when writing / erasing with a thermal head or the like. There is no damage to the part. Therefore, the information recording and display card can be used even if writing / erasing is repeated many times.

Further, since the undercoat layer made of an elastomeric material is interposed between the overcoat layer and the visible information display section, the undercoat layer absorbs a volume change at the time of phase transition of the polymer material, and The stress generated in the visible information display section is reduced, and cracks, which are likely to occur in the visible information display section during erasing, are prevented. Further, the contrast ratio at the time of writing and at the time of erasing is ensured. Furthermore, since the overcoat layer is laminated on the undercoat layer, the overcoat layer also protects the surface of the undercoat layer, and the function of the undercoat layer is maintained for a long time.

〔Example〕

Hereinafter, a specific embodiment of an information recording / display card to which the present invention is applied will be described. In this embodiment, a drawing (DRAW) type optical card using a polymer nematic liquid crystal for a visible information display portion is taken as an example. This will be described with reference to FIG.

As shown in FIGS. 1 (a) and 1 (b), the optical card (1) has an invisible information recording unit (2) on the card surface and a visible information display unit (3) on the back surface of the card. It is configured.

Further, as shown in FIG. 2, the invisible information recording section (2) and the visible information display section (3) are separately manufactured and then joined and integrated by an adhesive layer (8) made of an adhesive or the like. Things.

The invisible information recording section (2) is arranged on one main surface of a first card substrate (9) made of, for example, a polycarbonate plate. The first card board (9)
Is provided with a protective layer (10) made of an acrylic hard coat film.

Here, the invisible information recording section (2) is formed by, for example, sequentially depositing Sb ₂ Se ₃ and Bi ₂ Te ₃ as write-once optical recording materials on the first card substrate (9). Things. In addition, a Sb ₂ Se ₃ / Bi ₂ Te ₃ / Sb ₂ Se ₃ three-layer write-once optical recording material may be used. Further, tellurium compounds such as TeC and TeOx, cyanine compounds, phthalocyanine compounds, etc. Organic dye-based write-once type recording material. Furthermore, not only write-once optical recording materials but also rewritable types (E-DRAW type)
An optical recording material such as a TbFeCo-based magneto-optical recording material or a chalcogenite-based phase-change recording material may be used as the invisible information recording portion.

On the other hand, the visible information display section (3) is arranged on a second card substrate (4) made of, for example, a polyethylene terephthalate (PET) film via a light-heat reflection layer (5) made of an aluminum vapor-deposited film. It has been done.

For the visible information display section (3), a polymer nematic liquid crystal which reversibly undergoes a phase transition by light or heat and selectively takes a transparent state and an opaque state at room temperature was used. The polymer nematic liquid crystal includes, for example, the following (a)
Side chain type polymer nematic liquid crystals such as cyanobiphenyl-based, azomethine-based, phenylbenzoate-azomethine-based, or copolymers of cyanophenylbenzoate and methoxybiphenylbenzoate having the molecular structures of (d) to (d) are suitable.

In the side chain type polymer nematic liquid crystal of (a) to (d), the phase transition occurs because the thermal motion of the mesogen in the side chain is decoupled by the thermal motion of the carbon-carbon bond portion of the main chain and the methylene bond. Faster behavior is achieved.

Further, the side chain type polymer nematic liquid crystals according to the examples (a) to (d) are characterized in that the isotropic phase transition temperature Tcl exists on the higher temperature side than the glass transition temperature Tg. For this reason,
At room temperature below the glass transition temperature Tg, no phase transition occurs and the displayed information is stably stored.

In addition, the isotropic phase transition temperature Tc of the above polymer nematic liquid crystal
An infrared absorber or a low-molecular liquid crystal may be added in order to lower the l and the glass transition temperature Tg.

Examples of the infrared absorbent include compounds having the following molecular structures (e) and (f).

(R is hydrogen or a lower alkyl group, X is any one of hexafluoroarsenate ion, hexafluoroantimonate ion, fluorinated borate ion, and perchlorate ion, and m represents an integer of 0 to 2.) These are commercially available, for example, under the trade name PA-1006 (manufactured by Mitsui Toatsu) and trade name IRG-003 (manufactured by Nippon Kayaku).

For example, if a predetermined amount of the compound (e) (trade name PA-1006) is added to the polymer nematic liquid crystal, the isotropic phase transition temperature Tcl can be arbitrarily lowered as shown in FIG. . For example, without addition, the isotropic phase transition temperature Tcl
Is 114 ° C., but isotropic phase transition temperature Tcl is 10
The temperature becomes 8 ° C., and the isotropic phase transition temperature Tcl becomes 102 ° C. by adding 2%. The amount of the infrared absorber added can be up to 20%, but is more preferably 10% or less.

Further, in addition to the infrared absorbing agent and the like, for example, a dye that absorbs ordinary visible light may be used. For example, Sudan I having the following molecular structure (g) can be used.

On the other hand, low-molecular liquid crystals include cyanobiphenyl-based, cyanophenylcyclohexane-based, cyanophenyl ester-based, benzoic acid phenyl-ester-based, cyclohexylcarboxylic acid phenyl-based, and phenyl phenyl-based compounds having the following molecular structures (h) to (m): Examples of the liquid crystal include pyrimidine-based liquid crystals.

Any of the low-molecular liquid crystals may be of any type or phase series, and it is important that the isotropic phase transition temperature at which the liquid crystal becomes isotropic is lower than the isotropic phase transition temperature of the polymer nematic liquid crystal.

By adding a predetermined amount of the low-molecular liquid crystal to the high-molecular nematic liquid crystal, as shown in FIG.
l can be reduced. Further, as shown in FIG. 6, between the isotropic phase transition temperature of the high molecular nematic liquid crystal and the isotropic phase transition temperature of the low molecular liquid crystal, an arbitrary isotropic phase transition temperature can be obtained depending on the composition. However, in order not to lower the glass transition temperature Tg of the polymer nematic liquid crystal, it is better to use a small amount of liquid crystal having a low isotropic phase transition temperature.

Here, the principle of operation of initialization, writing and erasing of the visible information display section (3) mainly composed of the polymer nematic liquid crystal will be described with reference to FIGS. 3 and 4. FIG. These figures show the phase transition behavior of the polymer nematic liquid crystal, with the horizontal axis representing temperature and the vertical axis representing free energy.

Initialization Initially, initialization will be described with reference to FIG.

The visible information display part (3) mainly composed of a polymer nematic liquid crystal immediately after coating and drying has an isotropic amorphous glass phase F
In addition, optically transparent, information cannot be written as it is. For this reason, first, the isotropic amorphous glass phase F is heated to a temperature near or above the isotropic phase transition temperature Tcl, and then slowly annealed to produce small liquid crystal domains, which scatter light of 600 nm or less. Therefore, it becomes cloudy. Hereinafter, this phase is referred to as a liquid crystal glass phase A. This phase is a background phase for characters, numbers, figures, etc. displayed on the visible information display section (3). Therefore, by making the entire visible information display section (3) opaque and opaque liquid crystal glass phase A, preparation of information display, that is, initialization, was completed.

Writing Next, writing will be described with reference to FIG.

When a thermal head or a light beam is applied to the visible information display portion (3) in the cloudy opaque liquid crystal glass phase A and the temperature is raised, the portion becomes a liquid crystal phase B when the glass transition temperature Tg is exceeded, and further becomes an isotropic phase. If the temperature exceeds the transition temperature Tcl, it enters the region of the unstable liquid crystal phase C. However, since the C phase is in an unstable state with a high free energy, it immediately transitions to the isotropic liquid phase D which is a low energy phase. When this D phase is rapidly cooled, it becomes an unstable isotropic phase E. Since this phase passes through in a very short time, the transition to the more stable liquid crystal phase B is suppressed, and the transparent isotropic non-phase is instantaneously (several msec or less). Then, the display information is frozen and stored.

Erasing Next, erasing will be described with reference to FIG.

The display information in the transparent isotropic amorphous glass phase F described above becomes unstable isotropic phase E when the temperature exceeds the glass transition temperature Tg when the temperature is increased by irradiating a thermal head or a light beam, and further, the isotropic phase transition temperature Reach Tcl. When annealing is performed by gradually cooling from a temperature near this temperature, the liquid crystal phase B is fixed to the liquid crystal glass phase A at room temperature through the liquid crystal phase B having a small free energy. At this time, the visible information display section (3) returns to the cloudy and opaque initialization state within several seconds, the past display information is completely erased, and the next writing can be performed again.
Note that these writing and erasing can be repeated repeatedly.

In particular, in the optical card (1) of this embodiment, an undercoat layer (6) and an overcoat layer (7) are sequentially laminated as protective films on the visible information display section (3). The undercoat layer (6) is a film made of an elastomeric material such as urethane, while the overcoat layer (7) is a film made of a material having excellent heat resistance such as an ultraviolet curable resin. I have.

Writing and erasing information on the visible information display section (3) of the information recording / display card (1) configured as described above can be performed using, for example, a thermal head.

That is, the invisible information recording unit (2) records, for example, the amount of payment, the balance of the account, and the like as a dot row by a laser beam device built in a card reader / writer each time the device is used. On the other hand, the visible information display unit (3) has information based on the content recorded in the invisible information recording unit (2) or the content recorded in the card reader / writer or a storage device connected thereto, for example, the balance. Are written by a printer having a thermal head built in the card reader / writer.

On the other hand, the written information can be erased by thermal annealing of the thermal head.

In the present embodiment, the visible information display section is provided on the card surface opposite to the invisible information recording section. However, if the function of the invisible information recording section is not impaired, the visible information display section and the invisible information recording section can be placed on the same surface of the card substrate. May be arranged.

Further, in the present embodiment, the visible information display portion was provided at the stage of manufacturing the information recording display card, but separately from this, the visible information display portion mainly composed of polymer nematic liquid crystal was provided on the substrate surface of the already completed information recording card. You may make it adhere | attach the adhesive film provided with.

In addition, the present invention is not limited to an optical card, and a card having another invisible information recording unit, for example, a magnetic card, a visible information display unit provided on a card substrate such as an IC card at a place where the information recording function is not impaired, and a magnetic stripe It is also possible to display contents based on contents recorded in an IC memory or the like, and further information based on contents recorded in a card reader / writer or a storage device connected thereto.

Here, after actually producing six types of information recording / display cards based on the following conditions, writing / erasing was performed using a flash light and a thermal head. Experimental Example 1
Indicates that there was no protective film, the protective films were one layer in Experimental Examples 2 and 3, and two protective films were used in Experimental Examples 4 to 6.

Experimental Example 1 Aluminum was deposited on a polyethylene terephthalate film to form a light-heat reflective layer. Thereafter, a cyanobiphenyl-based polymer nematic liquid crystal having the above-described molecular structure and an infrared absorbing agent (Mitsui Toatsu PA-1006) 2
% By weight was dissolved in a solvent such as cyclohexane, and this solvent was coated on the light-heat reflecting layer to form a visible information display portion.

Then, writing with flash light was performed from the visible information display portion side, and then erasing was performed by applying heat from the film side.

As a result, the contrast ratio at the time of writing and at the time of erasing is 5.0, 16 at 5.0 and 9.0 μm when the thickness of the visible information display portion is 5.0 μm.
It was 4.0 in μm.

Next, the same sample was written and erased by a thermal head.

As a result, the contrast ratio obtained almost the same value as in the case of the flash light, but the visible information display portion was damaged during writing.

For this reason, in order to prevent the visible information display portion from being damaged, 10 wt% of aerosil was added to the polymer nematic liquid crystal, and this was coated on the light-heat reflection layer by 9.0 μm to prepare an information recording / display card. The Aerosil used was 300 mm diameter manufactured by Degussa.

Then, when writing was performed on this sample by flash light, the contrast ratio was 3.4, which was lower than that without Aerosil. Next, when writing was performed on this sample by a thermal head, the damage at the time of writing was reduced, but was not completely eliminated.

Experimental Example 2 A UV-curable acrylic hard coat agent was coated on the visible information display section at 2 μm to prepare a UV-cured sample. The UV-curable acrylic hard coat agent used was HO-7946 (trade name, manufactured by Fujikura Kasei Co., Ltd.).

This sample was prepared by depositing aluminum on a polyethylene terephthalate film to form a light-heat reflective layer in the same manner as in the first experimental example, and then forming a cyanobiphenyl-based polymer nematic liquid crystal and an infrared absorbing agent (Mitsui Toatsu). PA-1
006) Dissolve 2% by weight in a solvent such as cyclohexane,
This solvent was coated on the light-heat reflection layer to form a visible information display portion.

The sample was written with flash light from the visible information display side, and then erased by applying heat from the film side.

As a result, the contrast ratio at the time of writing and at the time of erasing was 3.0 when the thickness of the visible information display portion was 9.0 μm and 3.6 and 16 μm. Thus, the contrast ratio was reduced to about 70% by providing the protective film using the ultraviolet-curable acrylic hard coat agent as compared with the case where the protective film was not provided.

Next, the same sample was written and erased by a thermal head.

As a result, no damage was found on the surface of the visible information display portion at the time of writing, but a crack was generated at the time of erasing, and repeated writing / erasing could not be performed near the cracked portion. Further, it was found that since the liquid crystal layer was formed into a mono-domain, light scattering was not performed, and a part that would remain undisturbed was found.

Next, a sample in which a visible information display portion was formed by adding 10% by weight of Aerosil to the above-mentioned UV-curable acrylic hard coat agent was prepared, and writing and erasing were performed in the same manner. However, there was no damage on the surface of the visible information display portion at the time of writing by the thermal head, and no crack was generated at the time of erasing.

This is probably because the addition of Aerosil suppresses thermal expansion and contraction.

Experimental Example 3 Two thermosetting urethane coating agents were applied on the visible information display.
The sample of Experimental Example 3 was prepared by coating with μm and thermally curing at 80 ° C. for 6 hours. The thermosetting urethane coating agent used was ET-5406 (trade name, manufactured by Fujikura Kasei Co., Ltd.).

As in the case of Experimental Example 1 above, this sample was formed by evaporating aluminum on a polyethylene terephthalate film to form a photothermal reflection layer, and then forming a cyanobiphenyl polymer nematic liquid crystal and an infrared absorbent (Mitsui Toatsu product) PA-1006) 2% by weight was dissolved in a solvent such as cyclohexane, and this solvent was coated on the light-heat reflecting layer to form a visible information display portion.

Then, writing and erasing were performed on the sample from the visible information display side using a flash light and a thermal head.

As a result, when the thickness of the visible information display portion is 9.0 μm,
The contrast ratio at the time of writing and erasing was increased to 4.4. In addition, the surface of the visible information display portion was hardly damaged during writing with the thermal head, and no crack was generated during erasing. Furthermore, stress relaxation was caused by the elastomeric properties, and no alignment of the polymer nematic liquid crystal was caused.

However, the damage at the time of writing and erasing by the thermal head is somewhat seen as compared with the protective film made of the ultraviolet-curable hard coat agent, and thus the film has lower resistance than the hard coat agent of the ultraviolet hardener.

Experimental Example 4 A silica fine powder was coated on the protective film of the sample used in Experimental Example 3 with a thermosetting urethane-based coating agent through a primer.
μm was coated. Then, the above silica fine powder is 90 ° C at 90 ° C.
Heated for a time to thermally cure.

In addition, the above silica fine powder is trade name Ceramate C-503
(Manufactured by Catalyst Chemical Industry Co., Ltd.). This Ceramate C-503
Is a silica fine powder having a diameter of 100 mm, which is coated with SiO ₂ gel by heating after coating.

Then, when writing and erasing were performed on this sample using a flash light and a thermal head, the contrast ratio was unchanged from that in Experimental Example 3 above, and there was no damage on the surface of the visible information display portion during writing or erasing. .

When this silica fine powder was directly coated on the visible information display portion, the protective layer was made of a UV-curable acrylic hard coat agent having a high contrast ratio (Experimental Example 2).
It was only about 3.5 which was the same as the sample provided with.

Experimental Example 5 Parylene N, Parylene C and Parylene D (trade names) were coated on the protective film of the sample used in Experimental Example 3 with a thermosetting urethane-based coating agent at 2 μm and 5 μm, respectively, to form a protective film.

Parylene (UCC) can be polymerized by radical polymerization of monomers on a substrate by CVD, and as a result, a polymer thin film having a uniform thickness, a solvent-insoluble property and a high crosslinking density can be formed. Things. Although the glass transition temperature Tg of this parylene is about 100 ° C., it has a high elastic modulus of about 10 ¹⁰ dyn / cm ² even at a high temperature (for example, 200 ° C.).

When writing and erasing were performed on this material using a flash light and a thermal head, the contrast ratio was the same as that in Experimental Example 3. When the thickness of the protective film was 2 μm or 5 μm, no damage was observed on the surface of the visible information display portion at the time of writing or erasing, no crack was generated, and no disappearance was observed.

However, the sharpness of the characters at the time of writing with the thermal head was better when the thickness of the protective film was 2 μm.

Experimental Example 6 A sample was prepared by coating the UV-curable acrylic hard coating agent used in Experimental Example 2 on the protective film of the sample used in Experimental Example 3 with the thermosetting urethane coating agent.

When writing and erasing were performed on this sample using a flash light and a thermal head, the contrast ratio was as high as 4.4, and no damage was observed on the surface of the visible information display portion during writing. In addition, no cracks were generated at the time of erasing and no disappearance was observed.

As is clear from the above experimental results, in all of Experimental Examples 4 to 6, since the visible information display portion was free from scratches and cracks at the time of writing and erasing, and the contrast ratio was good, the protective film was formed. Has a two-layer structure, whereby an information recording / display card showing more excellent characteristics can be obtained.

〔The invention's effect〕

As is clear from the above description, according to the information recording and displaying card of the present invention, an undercoat layer made of an elastomer-based material for relaxing stress on the visible information display portion and ensuring a contrast ratio, Since the overcoat layer made of a heat-resistant material for preventing the surface of the display unit from being damaged is overlaid and laminated, it is necessary to prevent the visible information display unit from being damaged when writing and erasing with a thermal head or the like. And the contrast ratio is ensured, so that it can be used many times.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 (a) and 1 (b) are plan views showing the appearance of an information recording / display card to which the present invention is applied, and FIG. 1 (a) shows the card surface. FIG. 1B is a plan view showing the back surface of the card. FIG. 2 is an enlarged sectional view of a main part of the information recording and displaying card. 3 and 4 are explanatory diagrams of the operation of initializing, writing, and erasing the visible information display section using the polymer nematic liquid crystal. FIG. 3 is an explanatory diagram of the operation of writing, and FIG. It is operation | movement explanatory drawing of FIG. FIG. 5 is a characteristic diagram showing the relationship between the amount of the infrared absorber added and the isotropic phase transition temperature. FIG. 6 is a characteristic diagram showing the relationship between the amount of low-molecular liquid crystal added and the isotropic phase transition temperature. DESCRIPTION OF SYMBOLS 1 ... Optical card 2 ... Invisible information recording part 3 ... Visible information display part 4 ... 2nd card board 5 ... Light heat reflection layer 6 ... Undercoat layer 7 ... Overcoat layer 9 ... 1st Card board

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masato Yamamura 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-62-290579 (JP, A) 61-105178 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B42D 15/10 B41M 5/26

Claims (1)

(57) [Claims] 1. A visible information display section using a phase transition mode by heating of a polymer material for at least one of recording and erasing, wherein an undercoat layer made of an elastomeric material is provided on the visible information display section. An information recording and display card characterized in that an overcoat layer made of a material excellent in quality is sequentially laminated.