JPH05294092A - Card permitting rewriting - Google Patents

Abstract

PURPOSE:To provide a card permitting rewriting in which writing and extinction of the indication on the card can be conducted by the operations for applying heat and electric field repeatedly. CONSTITUTION:A card 1 permitting rewriting consists of a composite film layer 3 which is composed of a polymer-liquid crystal material containing a substrate sheet 2, a polymer material with a film-forming property formed on the surface of the substrate sheet, and a liquid crystal material and a protective resin layer 4 which is formed on the surface of the composite film layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card for recording information, and erasing and re-recording of the display recorded on the card can be performed by repeating a heating operation and an electric field passing operation. Provide a rewritable card that can.

[0002]

2. Description of the Related Art A liquid crystal substance changes the directionality of internal molecules when external conditions such as temperature, electric field, and magnetic field change, and exhibits optical changes such as color and transparency.
It is applied to display devices such as instrument panels, calculators, watches, and ultra-thin TVs.

[0003]

In recent years, prepaid cards and the like have been widely used in which the date and time of use of the card and the amount of money can be written each time. A prepaid card or the like in which the date and time of use and the amount of money of this card can be written each time has the convenience that the user of the card can check the balance at any time. However, with this type of card, the recording area is limited by itself, so the recorded portion of the card often fills before the entire amount of the amount attached to the card is consumed, and another new card However, this is not preferable in terms of resource saving as well as the trouble of reissuing a card according to the balance.

On the other hand, the present invention comprises a card using a composite film layer of a polymer substance and a liquid crystal substance containing a polymer substance and a liquid crystal substance as a recording layer, and requires a heating operation and a strong electric field. Provided is a so-called rewritable card capable of repeatedly erasing a record and re-recording by repeating an operation of applying an electric field.

[0005]

A rewritable card according to the first aspect of the present invention comprises a base material sheet, a polymer material having film-forming performance and a liquid crystal material formed on the surface of the base material sheet. A composite film layer composed of a polymer substance and a liquid crystal substance contained therein,
It is a punched product of a laminated sheet having a protective resin layer formed on the surface of the composite film layer.

The rewritable card according to the second aspect of the present invention is the rewritable card according to the first aspect of the present invention, wherein the rewritable card contains a polymer substance having a film-forming performance and a liquid crystal substance. The composite film layer made of the liquid crystal material has 10 parts by weight of the liquid crystal material with respect to 100 parts by weight of the polymer material having film forming performance.
.About.500 parts by weight.

The rewritable card of the third invention is
In the structure of the rewritable card according to the first invention or the second invention, in a composite film layer of a polymer substance / liquid crystal substance containing a polymer substance having film forming performance and a liquid crystal substance, It consists of containing dichroic dye molecules that match the molecules of the liquid crystal material in the composite film layer and perform the same optical function as the liquid crystal material.

In the rewritable card of the present invention having the above structure, the base sheet is a sheet having rigidity required for carrying, for example, a polyester film such as polyethylene terephthalate film or polybutylene terephthalate film, or polymethacrylic acid. Methyl,
Acrylic resin films such as poly (methyl acrylate) and poly (ethyl methacrylate), as well as polystyrene films, acrylonitrile / butadiene / styrene copolymer films, cellulose triacetate films, polycarbonate films, etc. having a thickness of about 100 to 1000 μ used. In addition to these, general paper such as art paper, coated paper, high-quality paper, synthetic paper, metal foil, ceramic sheet and the like may be used according to the purpose.

The composite film layer composed of a polymer substance / liquid crystal substance containing a liquid crystal substance and a polymer substance having film forming ability formed on the surface of the base sheet is a high-performance liquid crystal substance having a film forming ability. A composite membrane layer in which a molecular substance is dispersed substantially uniformly by a method such as a microencapsulation method, a solvent evaporation method, a suspension polymerization method, an ionizing radiation curing method, and the presence of the composite membrane layer , The recording characteristic and the characteristic capable of erasing recorded information are provided to the card of the present invention.

In the composite film layer composed of this polymer substance / liquid crystal substance, the polymer substance preferably has good film-forming ability and heat resistance, for example, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer Vinyl chloride resin such as coalesce, vinylidene chloride resin such as polyvinylidene chloride,
Polyester resins, polyamide resins, polyacrylates, polymethacrylates, acrylic resins such as acrylate / methacrylate copolymers, polyurethane resins, etc. are used. At this time, the acrylic monomer or prepolymer may be mixed and then cured by ionizing radiation.

The liquid crystal substance is a smectic liquid crystal polymer having a memory property, for example, BDH chemistry (BDH Chemica) of Pool, England.
"Smectic A phase material S2" commercially available from l)
And Darmstadt in West Germany
E. Merck Chemicals (E. Merck Chemical
s) commercially available K24, K30, K36, ZL
I1840, CB15, etc. are used.

Of course, nematic liquid crystals, cholesteric liquid crystals, discotic liquid crystals, polymer liquid crystals, and mixed systems thereof can also be used. Further, it is possible to cause a state transition during heating to facilitate writing.

For example, since 4,4'-di-heptyloxyazoxybenzene causes a state transition to a smectic C phase at 74 ° C and a nematic phase at 95 ° C, a thermal printer can raise the temperature to 75 ° C or higher. It is also possible to disturb the orientation by heating to cause color development, and then similarly to heat at 74 to 95 ° C. and re-orient by applying an electric field to erase the color.

Examples of liquid crystal compounds include Schiff base compounds, benzoic acid ester compounds, biphenyl compounds, cyclohexylcarboxylic acid ester compounds, phenylcyclohexane compounds, pyridine compounds, dioxane compounds, cyclohexyl cyclohexane compounds, etc. for the above-mentioned purposes. It is preferable to use a suitable molecular weight.

In a composite film layer made of a polymer substance and a liquid crystal substance having film forming performance, when the liquid crystal substance is less than 10 parts by weight with respect to 100 parts by weight of the polymer substance, the printing sensitivity of recording in the composite film layer. Is likely to be low, making it difficult to obtain clear recording. Further, when the amount of the liquid crystal material exceeds 500 parts by weight with respect to 100 parts by weight of the polymer material, the amount of liquid crystal seeping out to the surface of the composite film layer increases, so It is easy to form a protective resin layer. Therefore, in the composite film layer of the polymer substance / liquid crystal substance having film forming performance, the liquid crystal substance 10 to 100 parts by weight of the polymer substance having film forming performance is used.
It is preferable to use 500 parts by weight, more preferably about 50 to 200 parts by weight of the liquid crystal substance.

Further, in the composite film layer of the polymer substance / liquid crystal substance, dichroic dye molecules that match the molecules of the liquid crystal substance in the composite film layer and perform the same optical function as the liquid crystal substance are provided. By including it, the color of the recording portion can be made more clear. As this dichroic dye molecule, for example,
Indore Blue, Sudan Black B, Sudan 3, Sudan 2, and E.I. Merck Chemicals (E. Mer
D-3 commercially available from K Chemicals)
7, D-43, D-85 and the like can be used.

A composite film layer composed of a polymer substance / liquid crystal substance containing a polymer substance having film forming performance and a liquid crystal substance,
A coating agent composed of a composition prepared as a coating agent for forming the composite film layer was applied to the surface of the substrate sheet by, for example, a blade coating method, a reverse coating method, a gravure coating method, or the like. After that, this is dried to form a thickness of about 1 to 50 μm.

The composite film layer may be formed by mixing an ionizing radiation curable material and a liquid crystal material so that the composite film layer becomes a substantially dispersed layer when cured. In addition, the composite membrane layer, for example,
Of course, it may be partially provided by silk screen printing, offset printing, or the like.

The protective resin layer formed on the surface of the composite film layer of the polymer substance / liquid crystal substance containing the polymer substance having the film forming performance and the liquid crystal substance is a composite film of the polymer substance / liquid crystal substance. It is for the purpose of protecting the layer, and it is necessary to have an action having excellent robustness. The protective resin layer is, for example, an ionizing radiation curable resin made of a mixed resin composition of a silicone resin or a prepolymer having a polymerizable unsaturated bond or an epoxy group in the molecule, an oligomer, and / or a monomer. It is formed to a thickness of about 0.5 to 10 μm by a coating agent using the above.

Further, after the above-mentioned composition and the protective resin are simultaneously coated in multiple layers, or immediately after the above-mentioned composition is coated and the protective resin is overlaid, it is usually dried or irradiated with ionizing radiation to be cured. Alternatively, a method of closing with a protective layer before bleeding of liquid crystal can be used. At this time, of course, a similar effect may be obtained by using, for example, a polyethylene terephthalate film having a thickness of 3 μm as a material for the protective layer from the beginning.

The rewritable card of the present invention having the above-described structure is heated by using, for example, a thermal printer, a thermal head, an optical means, or the like. The recording part in the film layer is confirmed through the protective resin layer. When using optical means, it becomes easy to heat while applying an electric field.

[0022]

The rewritable card of the present invention comprises a base material sheet, a polymer material / liquid crystal material formed on the surface of the base material sheet and containing a polymer material having a film-forming performance and a liquid crystal material. It has a composite film layer and a protective resin layer formed on the surface of the composite film layer, and the state of the composite film layer of the polymer substance / liquid crystal substance before heat-sensitive recording on the card is [ 2]. That is, when the card is passed through an electric field such as corona charging, the liquid crystal molecules in the liquid crystal particles dispersed in the composite film layer of the polymer substance and the liquid crystal substance in the card are aligned in the same direction, Since the materials and the liquid crystal material have the same refractive index, the composite film layer exhibits a transparent state.

Of course, an electric field may be applied directly by using an electrostatic roller. By using an electrostatic roller, a relatively strong electric field can be applied at high speed.

When heat sensitive recording is applied to the card in such a state, as shown in FIG. 3, the liquid crystal in the liquid crystal particles dispersed in the composite film layer of the polymer substance and the liquid crystal substance in the card is used. Since the molecules are randomly arranged and the refractive index of the polymer substance and the liquid crystal substance are different, only the heated part is visible as an opaque turbid state from the outside, and this is seen through the protective resin layer. Recognized as a recording unit. At this time, if a dichroic dye is added, it is visually recognized as a colored state.

When the dichroic dye is oily, when an aqueous polymer or an aqueous prepolymer is used as the high molecular material, the dye concentrates on the liquid crystal layer to form a composite film layer having a highly transparent background. can do. At this time, of course, the contrast also becomes large. The aqueous prepolymer can improve physical properties such as film strength by being cured after film formation.

Then, the thermosensitively recorded card is passed through the electric field again, so that in the composite film layer of the polymer substance and the liquid crystal substance in the card, the polymer substance and the liquid crystal in the composite film layer. Since the molecular directions of the substance and the substance are aligned in the same direction, the high refractive index of the polymer substance and the liquid crystal substance are matched and a transparent state is exhibited, so-called thermal recording is erased.
Then, a card which can be similarly subjected to thermal recording is obtained, and "writing-erasing" can be freely performed by repeating the thermal recording operation and the operation of applying an electric field.

In the above description, regarding the rewritable card of the present invention, the "writing-erasing" on the card was described based on the combined operation of "thermal recording-passing through an electric field". In the case of "writing-erasing" on the card based on the "Recording-erasing by heating" method, the recording part is visually confirmed by the transparent part and the erased state is visually recognized as a turbid state. You can do it. That is, when the arrangement of liquid crystal molecules in the liquid crystal particles is in a random state (turbid state), by partially applying an electric field with an ion head or the like, the portions where the liquid crystal molecules are aligned in the same direction and become transparent are recorded portions. When erasing the recording portion, the liquid crystal molecules are disturbed by heating with a thermal head or the like to form a turbid state. "Write-erase" on the card by such a mechanism
Since the recorded part is visually recognized as a transparent part, it is possible to improve the visibility of the recorded part by forming a colored layer under the composite film layer of the polymer substance and the liquid crystal substance. You can

[0028]

EXAMPLES The concrete structure of the rewritable card of the present invention will be described below with reference to manufacturing examples.

Example 1 In FIG. 1, the surface of a base sheet 2 made of a biaxially stretched polyethylene terephthalate film having a thickness of 200 μ is coated on a surface of a base material sheet 2 with a polymer / liquid crystal substance having the following composition to form a composite film layer. (1) was applied by a blade coating method and then dried by heating to form a composite film layer 3 of a polymer substance / liquid crystal substance having a thickness of 10 μm.

Coating agent (1) Methyl methacrylate polymer: 100 parts by weight BDH of Pool, UK "Liquid crystal substance S2 based on smectic A phase substance" commercially available from Kagaku (BDH Chemical): 100 parts by weight Methyl ethyl ketone: 300 parts by weight Toluene ... 300 parts by weight

Next, a coating agent by UV curable resin "SEICA BEAM; Dainichiseika Kogyo" having a viscosity of 100 cps / 25 ° C. is applied to the entire surface of the composite film layer 3 made of the above-mentioned polymer substance / liquid crystal substance by the comma coat method. Coated and then 160W /
Irradiation of ultraviolet rays by a high pressure mercury lamp of 10 cm conveyer speed 10
By carrying out at m / min., a protective resin layer 4 having a thickness of 5 μm was formed to obtain a sheet having a laminated structure corresponding to the laminated structure of the rewritable card according to one embodiment of the present invention. Subsequently, this laminated sheet was punched and molded into a card of 85 mm × 54 mm to obtain a rewritable card 1, which is one embodiment of the present invention and is indicated by reference numeral 1 in FIG.

[Experiment] The card 1 obtained in the embodiment is set to 5K.
0.3m with a thermal head after V corona charging
When subjected to heat-sensitive recording of J / dot, the recorded print was visually recognized as a cloudy state through the protective resin layer. Further, when this thermosensitively recorded card was subjected to corona charging of 5 KV, the recording was erased, and the card was returned to the same state as the state before the thermosensitive recording was applied.

[0033]

The rewritable card of the present invention is capable of erasing the recorded display and re-recording by repeating the heating operation and the operation of applying the electric field. For recent prepaid cards that require the acquisition of various information such as the amount of money, if the first recorded portion becomes full before the total amount of money attached to the card is finished After erasing, new recording can be performed. Therefore, even if the first recording part becomes full before the total amount of money attached to the card is finished, there is no need to recreate another new card, and a new card is created. The complexity and financial burden of reworking are reduced, and there is an advantage in resource saving.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a laminated structure of an embodiment of a rewritable card of the present invention.

FIG. 2 illustrates a state where liquid crystal molecules in liquid crystal particles dispersed in a composite film layer of a polymer substance and a liquid crystal substance are aligned in the same direction, and the refractive indices of the polymer substance and the liquid crystal substance are the same. It is a model cross section.

FIG. 3 shows a random arrangement of liquid crystal molecules in liquid crystal particles dispersed in a composite film layer of a polymer substance and a liquid crystal substance, which causes a difference in refractive index between the polymer substance and the liquid crystal substance. It is a model cross section explaining the state visually recognized from the outside as an opaque turbid state.

[Explanation of symbols]

1 rewritable card 2 base sheet 3 composite film layer of polymer substance / liquid crystal substance containing polymer substance and liquid crystal substance having film forming performance 4 protective resin layer n, n polymer substance / liquid crystal substance Liquid Crystal Material in Composite Membrane Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G11B 7/24 571 H 7215-5D

Claims (3)

[Claims] 1. A base material sheet, and a polymer / liquid crystal material composite film layer containing a liquid crystal material and a polymer material having film-forming performance formed on the surface of the base material sheet,
A rewritable card having a protective resin layer formed on the surface of the composite film layer. 2. A composite film layer of a polymer substance / liquid crystal substance containing a polymer substance having film forming performance and a liquid crystal substance, wherein the liquid crystal substance 10 to 100 parts by weight of the polymer substance having film forming performance. A rewritable card according to claim 1 containing 500 parts by weight. 3. A dichroic dye molecule in which a composite film layer of a polymer substance / liquid crystal substance containing a polymer substance having film forming performance and a liquid crystal substance is aligned with molecules of the liquid crystal substance in the composite film layer. A rewritable card according to claim 1 or claim 2, which comprises: