JPH08333444A - Thermally recording card - Google Patents

Abstract

PURPOSE: To obtain a thermally recording card having gate characteristics such as rigidity necessary in mechanical read and write, a thermal printing function and the decomposability of the whole card constituion by using a specified support. CONSTITUTION: This thermal recording card is one prepared by laying a coloring layer, a thermal recording layer made of a thin low-melting metal film and a heat-resistant protectie layer on at least either surface of a support in the given order, wherein the support is made of a material based on a decomposable resin. As the decomposable support, a biodegradable resin selected from among microbially produced polyesters, chemically synthetized polyesters, natural- product-derived resins and aliphatic polyesters comprising lactic-acid-based polymeric materials is used. Their examples include aliphatic polyesters comprising hydroxyalkanoate units, chemically synthesized polyesters represented by formulas I and II (wherein R1 and R2 are each a 2-10C alkylene, a cyclo-ring or a cycloalkylene; and R3 is a di- or poly-isocyanate group), composite starch/ PVA resins and polylactic acid (copolymers).

Description

Detailed Description of the Invention

[0001]

The present invention relates to a tag label, tape,
Used for forms such as prepaid cards, pass tickets, entrance tickets, tickets, computer output paper, etc., and disposable type of OA materials, the entire structure of the thermal recording medium is biodegradable, thermal head and laser beam The present invention relates to a heat-sensitive recording card in which image information is recorded by heating with heat.

[0002]

2. Description of the Related Art Conventionally, thermal recording media for recording image information such as characters and figures by causing chemical or physical changes by thermal energy from a thermal head or laser beam have been used in a wide range of fields. ing. In particular, what is most used in the card field is a so-called prepaid card in which a fixed amount of money is paid in advance and the value information for that amount is recorded. Polyethylene terephthalate is used as the base material for these general cards,
Polyvinyl chloride and the like are known. Usually, this type of card is sold or rented to the user, and then discarded when the user finishes using the card. And
The plastic card of this material is currently disposed of by incineration or landfill as waste after the treatment after use, but the plastic waste has a durability of the incinerator due to high combustion temperature by incineration. problem,
It has pollution problems such as combustion gas, and it is not complete, but it is incomplete. In addition, in the landfill as a waste, since it remains in its original form without being decomposed in the landfill, it remains semi-permanently as waste, which has a problem of affecting the natural environment, and there is a problem of disposal after use.

On the other hand, conventionally, a card using paper as a base material has been made and used. In particular, paper is considered to be the best card for solving environmental problems such as dust, because it is easy to dispose of such as incineration and landfill, and the manufacturing cost is low.

Further, Japanese Patent Application Laid-Open No. 57-150393,
JP-A-59-220192, JP-A-51-939
As described in JP-A-91, JP-A-63-260912, and JP-A-57-150393, plastics that can be decomposed in the natural environment such as light or underground have been developed, and particularly disposable products. It is used in packaging and is now partly commercialized.

[0005]

However, when paper is used as the substrate, the durability, bending resistance, water resistance, and
Since it is poor in chemical resistance, waterproofness, surface smoothness, glossiness, workability, etc., the use of paper alone is limited to temporary use such as pass tickets, admission tickets, boarding tickets, etc. for a certain period of time. Not suitable for prepaid cards used. In addition, it is conceivable that a synthetic resin such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, or an aluminum foil and an outer layer other than plastic are laminated as a protective layer on a paper base material, but these are not excellent in discardability, and plastic cards It does not change anything. Therefore, an object of the present invention is to provide a medium having gate characteristics such as rigidity required for machine reading / writing and a heat-sensitive printing function, and having the entire card structure decomposable.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been studied and devised in view of the above-mentioned problems, and provides a thermosensitive recording card which has a decomposability of the entire card and enables thermosensitive recording and has excellent mechanical characteristics. It is intended to provide a configuration. That is, the invention according to claim 1 is a heat-sensitive recording card in which a colored layer, a heat-sensitive recording layer, and a heat-resistant protective layer are sequentially laminated on a support, and the support forming the card is made of a degradable resin. A thermal recording card comprising a base material as a main component.

According to a second aspect of the present invention, the support having degradability is a hydroxyalkanoate such as 3-hydroxyvalerate, 3-hydroxybutyrate, 3-hydroxycaprolate or 3-hydroxyheptanoate. A heat-sensitive recording card, which is an aliphatic polyester having an ate unit and is a microorganism-produced polyester.

The invention according to claim 3 is the heat-sensitive recording card, wherein the decomposable support is a chemically synthesized polyester represented by [Chemical Formula 1] or [Chemical Formula 2].

According to a fourth aspect of the present invention, there is provided a heat-sensitive recording card in which the degradable support is a composite resin of starch and polyvinyl alcohol.

According to a fifth aspect of the present invention, the support having decomposability comprises a thermoplastic resin containing, as a main component, a polylactic acid or oxycarboxylic acid copolymer having a number average molecular weight of 10,000 to 1,000,000. It is a thermosensitive recording card characterized by comprising a decomposable polylactic acid resin formed by axial stretching.

According to a sixth aspect of the present invention, the support is formed by laminating the decomposable resin according to any one of the first to fifth aspects on one or both sides of a paper base material made of a naturally degradable material. Is a heat-sensitive recording card.

According to a seventh aspect of the present invention, there is provided a heat-sensitive recording card, wherein the colored layer is made of a magnetic material and colored with the magnetic material for the purpose of magnetic recording.

An eighth aspect of the present invention is the heat-sensitive recording card, wherein the resin of the colored layer is a biodegradable resin.

[0014]

According to the present invention, a card base material is biaxially stretched with a microorganism-produced polyester, a chemically synthesized polyester, a natural product-derived resin, a polylactic acid or a thermoplastic resin mainly containing a copolymer of lactic acid and oxycarboxylic acid. By using the degradable resin, the mechanical properties such as durability, rigidity, forming processability, mechanical strength, hardness, impact strength, dimensional stability, and bending resistance of the card base material are maintained. The gate characteristics for reading / writing on a machine can be improved, and even if it is left after being discarded, it can be sufficiently decomposed naturally. Further, since it has a low melting point metal thin film layer, it is possible to record image information such as characters and figures by causing a chemical change or a physical change by thermal energy from a thermal head or a laser beam.

The present invention will be described below in detail with reference to the drawings. In FIG. 1, a colored layer (12) is formed on the decomposable support (11) as required, a low melting point metal thin film layer (13) is formed on the colored layer, and a low melting point metal thin film layer is further formed. 1 is a cross-sectional view of a thermosensitive recording card according to an embodiment, which has a heat-resistant protective layer (14) formed thereon and is a basic constitution of the present invention.

In FIG. 2, a magnetic recording layer (15) colored with a magnetic material is formed on the decomposable support (11), and the magnetic recording layer and the low melting point metal are adhered to each other on the magnetic recording layer. Thermal sensitizing layer (16) to improve and further enhance thermal sensitivity
Forming a low-melting-point metal thin film layer (13) on the heat-sensitized layer.
FIG. 6 is a cross-sectional view of a thermal recording card in another example in which a heat resistant protective layer (14) is formed on the low melting point metal thin film layer. Further, the vapor deposition anchor layer and the intermediate layer may or may not be provided as the case requires.

In FIG. 3, a base material (1
A degradable resin is provided on one side or both sides of 7), and a colored layer (12) or a magnetic recording layer (1) is provided on the upper layer as necessary.
FIG. 5 is a cross-sectional view of a thermosensitive recording card according to another embodiment, in which the low melting point metal thin film layer (13) and the heat-resistant protective layer (14) are formed in this order by forming 5).

In FIGS. 1, 2 and 3, a degradable support (1
1) uses a biodegradable resin consisting of a microorganism-produced polyester, a chemically synthesized polyester, a natural product-derived resin, and an aliphatic polyester composed of a polymer material containing lactic acid as a main component, and these are completely degradable. . Also,
The decomposable resin can be laminated on one side or both sides of a base material such as paper that naturally decomposes. Resins that can be used include microorganism-produced polyesters such as 3-hydroxybutyric acid / 3-hydroxyvaleric acid copolymers, aliphatic polyesters such as polyglycolic acid, polylactic acid and polycaprolactone,
Polyvinyl alcohol (PVA), PVA modified resin, starch modified resin and the like can be used alone or in combination according to the required characteristics.

Particularly, lactic acid is a copolymer of D-lactic acid, L-lactic acid or a mixture thereof, D-lactic acid, L-lactic acid or a mixture thereof and glycolic acid or an oxycarboxylic acid represented by 6-hydroxycaproic acid. A thermoplastic decomposable resin whose main component is coalescence is used. This resin preferably has a number average molecular weight of 10,000 to 1,000,000. Lactic acid includes D-lactic acid and L-lactic acid, and oxycarboxylic acid is
Examples include glycolic acid and 6-hydroxycaproic acid. However, since the thermoplastic resin alone does not have sufficient rigidity, by further biaxially stretching, rigidity, durability, molding processability, mechanical strength, hardness, impact strength, dimensional stability, It has mechanical properties such as bending resistance and the same properties as conventional polyester materials and vinyl chloride materials in terms of surface smoothness, glossiness, water resistance and waterproofness.

The term "biodegradable" as used herein means that a polymer is decomposed into an oligomer, a monomer, or even a low-molecular substance by the action of an enzyme produced by a microorganism existing in the environment such as mold, bacteria, yeast and the like. It is desirable that the product be finally decomposed into water, carbon dioxide gas, methane and the like.

The heat-sensitive recording card of the present invention provides a card which does not remain as dust even after being used without being incinerated and landfilled or scattered in a natural environment.

If necessary, various additives such as 0.05 to 3 parts by weight of a coloring inhibitor and 0.05 to 3 parts by weight of an antioxidant are added to the above decomposable resin so long as the characteristics of the resin are not lost. It is possible to add 0.05 to 0.5 parts by weight of a lubricant, an organic pigment, an inorganic pigment and the like. However, it is not preferable to add a non-decomposable material in an amount of 50% or more because the decomposability is remarkably reduced and a processing problem occurs.

In particular, as fillers, inorganic fillers such as calcium carbonate, mica, calcium silicate, white carbon, asbestos, porcelain clay (calcined), and glass fibers are added, kneaded and biaxially stretched to obtain rigidity, Mechanical properties such as forming workability, mechanical strength, hardness, impact strength, dimensional stability, and bending resistance can be further improved.

Card substrate (11) which is the support of the present invention
The production of the thermoplastic resin obtained as described above,
The sheet is formed into a sheet shape by a known extrusion method, further biaxially stretched, and then this sheet is subjected to calendar treatment.
In addition to the single-layer structure, the card base material (11) is formed by stacking sheets made of the same material or resins having different characteristics.
There is no problem even if they are laminated by a known thermocompression bonding method or heat lamination method to form a multilayer structure.

Printing and processing on the card base material (11) produced by the above method can be carried out in the same manner as in the case of the conventional paper / plastic card, and the card base material (11) is offset. A card is manufactured by printing visible information / design such as characters and patterns by a printing method such as printing, screen printing, and gravure printing, and processing into a card size using a punching machine.

Further, the coloring layer (12) is a layer for imparting black, indigo, red or other hues to this support in order to distinguish it from the hue of the unrecorded portion of metallic luster tone or white matte tone. Gravure ink, offset ink, screen ink, paints for various coatings, etc. can be directly printed or coated, or can be applied by being attached to a support in the form of transfer foil or laminate. As the colorant, various color tones such as inorganic pigments and organic pigments can be used according to the application. As the polymer material, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, polyester resin, polyurethane resin, acrylic resin, polyvinyl alcohol, or other synthetic resin, or chitosan, natural rubber, or the like can be used. Natural resins are used alone or as a mixed system. Here, when the pigment component is increased in order to increase the concentration, the coloring layer (12) is liable to be absorbed by heat during recording of the metal melting type, and the recording sensitivity tends to decrease, and the coloring layer (12) is also reduced. When a conductive material is used for the colored layer, it cannot be said to be a stable recording medium because it causes metal corrosion. To remedy these drawbacks,
A heat-sensitive melt recording which provides a metal corrosion preventing function between the colored layer (12) and the low melting point metal layer (13) and improves the adhesiveness between the colored layer (12) and the low melting point metal layer (13). For the purpose of increasing the sensitivity at the time of, the heat sensitizing layer (16) (see FIG. 2) made of a thermoplastic resin may be provided. The resin that can be used as the heat-sensitive sensitizing layer is
Considering the adhesiveness to the base material and the low melting point metal layer, the same thermoplastic resin as that for the colored layer is used alone or in a mixed system.

Further, the colored layer (12) may be colored with a magnetic material and may be used as the magnetic recording layer (15). The magnetic recording layer (15) is formed of a magnetic ink in which a magnetic material is dispersed in a polymer material by a printing method or a coating method as a magnetic film having a residual magnetic flux density of 300 gauss to 5000 gauss and a film thickness of 5 to 20 μm. Polymer materials include vinyl chloride, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, polyester resin, polyethylene resin, polyurethane resin, acrylic resin, polyvinyl alcohol, degradable poly-ε-caprolactone. , Synthetic resins such as lactic acid, or natural resins such as chitosan and natural rubber are used alone or as a mixed system,
Preferably, polyvinyl chloride, polyvinyl chloride-vinyl acetate copolymer, polyester, degradable polyester, polyvinyl alcohol, chitosan, degradable poly-ε-caprolactone and lactic acid are used. Further, as the magnetic material, magnetite having a coercive force of 100 Oe or more, γ-iron oxide, C
Powders of metals and alloys such as deposited γ-iron oxide, barium ferrite, strontium ferrite, and chromium dioxide, and metal compounds can be used. Further, the magnetic recording layer (15) may be formed by a thin film forming method such as a vapor deposition method, a sputtering method, a plating method or the like other than the coating method and the printing method.

As the low melting point metal thin film layer (13), S
A simple metal such as n, Te, In, Pb or an alloy or compound of these metals can be formed by a method such as vacuum deposition, sputtering, plating, transfer, laminating, etc., but is easily melted by heat of a thermal head or the like. For this purpose, it is advantageous that the melting point is low, and in particular, a simple substance of Sn or an alloy of Sn is a practical and easy-to-use material. When the thickness of the metal thin film layer is about 100 to 5,000 liters, it is possible to have a concealing property of the colored layer and a recording function, but if the thickness is too thin or too thick, the printing sensitivity is lowered.
Before and after is desirable.

The heat-resistant protective layer (14) is an important constituent element that influences the use conditions of the heat-sensitive recording medium of the present invention, and usually comprises a heat-resistant resin, a lubricant and various fillers. Resins that can be used include thermoplastic acrylic resins,
Hard resin with heat resistance such as thermosetting acrylic resin, heat resistant acrylic emulsion resin, fluorine resin, various UV curable resins, OP varnish for offset printing and heat resistant polyester is used, especially for water-based paints. Acrylic emulsion with an average molecular weight of 1 considering heat resistance
Those containing 50,000 or more and those having a glass transition temperature of 90 ° C. or more as the main component give a sufficient protective function and a repeating function. Further, as the lubricant, silicone-based, metal stearate such as zinc stearate, or fluorine-based one can be used, but a wax-based lubricant should be used in consideration of abrasion resistance, coating film protection at heating, and sliding performance. Paraffin wax, microcrystalline wax, carnauba wax, rice wax, montan wax, low molecular weight polyethylene wax, oxidized polyethylene wax, low molecular weight polypropylene wax, various fatty acids, monoamide type, and bisamide having a melting point of 30 to 150 ° C. Various natural and synthetic waxes such as syrup, beef tallow, etc. are added alone or in a mixed system. Further, as additives, fillers such as calcium carbonate, talc, silica and alumina, various surfactants, stabilizers, curing agents and the like are used as necessary. The paints and inks composed of these can be used in various coating methods such as gravure coating, reverse roll coating, knife coating and blade coating, and printing methods such as gravure printing and screen printing.
It is provided with a film thickness of about 0 μm. Generally, water-based coating materials are more advantageous than solvent-based coating materials in terms of ease of handling and safety.Emulsion-based coating materials are particularly advantageous in coating and processing suitability because of low viscosity coating materials. It is used in various forms as a coating agent or adhesive for various paper processing, various building materials, industrial materials, etc. As described above, the use of the acrylic emulsion in the present invention is achieved by using particles having a stable and large molecular weight.
In addition to providing the physical strength of the coating film, the heat resistance of the coating film is provided by using a material having a high glass transition point (Tg) and a minimum film forming temperature (MFT), which exhibit heat resistance. As a measure of heat resistance, the minimum film forming temperature (MFT) is 60 ° C or higher, but preferably 100 ° C or higher.

[0030]

【Example】

<Embodiment 1> As Embodiment 1, the configuration of FIG. 1 will be described below. A thermosensitive recording card having the following layer structure was formed on a support (11) made of a degradable 3-hydroxybutyric acid-3-hydroxyvaleric acid copolymer film having a thickness of 200 μm. First, as the coloring layer (12), a coloring paint having the following composition was dried by a gravure method at a drying temperature of 130 ° C.
The coating was performed with a coating thickness of 3 μm. Chitosan 100 parts Black dye 30 parts Fine particle silica powder 2 parts Water 200 parts Acetic acid 10 parts As the metal thin film layer (13), the resistivity on the surface of Sn is 1.5Ω / □ by the vacuum deposition method. A low melting point metal thin film layer having a film thickness of about 1200Å was formed by a control method. Further, as the heat-resistant protective layer (14), an ultraviolet-curable offset OP varnish (Dicure ROP varnish: manufactured by Dainippon Ink and Chemicals, Inc.) was used in an offset printing machine to have a thickness of about 1.5 μm.
To obtain a thermosensitive recording card.

Example 2 As Example 2, a degradable polylactic acid film having a thickness of 200 μm and an average molecular weight of 150,000 was used as the degradable support (11). A thermal recording card was obtained with the same configuration as in Example 1 except for the above.

Example 3 As Example 3, a degradable lactic acid / oxycarboxylic acid copolymer having a thickness of 200 μm was used as the degradable support (11). A thermal recording card was obtained with the same configuration as in Example 1 except for the above.

<Embodiment 4> As Embodiment 4, the configuration of FIG. 2 will be described below. The colored layer (12) of Examples 1, 2 and 3 was used as a magnetic recording layer (15) using a magnetic material,
A thermal sensitizing layer (16) was formed under the low melting point metal thin film layer (13) in order to enhance the thermal sensitivity. Example 2 other than that
A thermosensitive recording card was obtained with the same structure as described above. For the magnetic recording layer (15), an ink having the following composition was formed by a gravure method at a drying temperature of 110 ° C. and a coating amount of φr = 1.4 Mx / cm.
After coating with, the coating was aged at 60 ° C. for 48 hours. Barium ferrite (coercive force 2750 Oe) 100 parts Polyvinyl alcohol 100 parts Isocyanate curing agent 5 parts Further, the heat sensitizing layer (16) was prepared by gravure coating the ink of the following composition with a drying temperature of 110 ° C. and a coating film thickness of 1.5 μm.
To obtain a heat-sensitive sensitizing layer (16). Polyurethane resin 30 parts Methyl ethyl ketone 50 parts Toluene 50 parts

Example 5 As Example 5, a magnetic recording layer (15) was prepared by using decomposable poly-ε-caprolactone as the resin in which the magnetic material was dispersed. A thermal recording card was obtained with the same structure as in Example 4 except for the above.

<Sixth Embodiment> A sixth embodiment having the configuration shown in FIG. 3 will be described below. The support is formed on a paper base material (17) having a thickness of 500 μm by an extrusion method known to those skilled in the art.
A degradable 3-hydroxybutyric acid-3-hydroxyvaleric acid copolymer having a thickness of 100 μm was laminated on both sides of a paper base material to obtain a support (11). Next, the colored layer (12), the metal thin film layer (13) and the heat-resistant protective layer (14) described in Example 1 were sequentially laminated on one surface of the support to form a thermosensitive recording card.

<Comparative Example 1> As Comparative Example 1, as a support, polyethylene terephthalate (PET) having a thickness of 200 μm is used.
Was used. The other configurations are the same as those described in the first embodiment.

The thermal recording cards produced in Examples 1 to 6 were capable of thermal destruction printing, and further, cards having good color development sensitivity were obtained. Moreover, this thermosensitive recording card was easily decomposed in an active state such as compost and field soil. Further, in the support of Example 1, in the field soil, after 6 months, the shape was not retained and only about half remained. On the other hand, the thermal recording card manufactured in Comparative Example 1 was capable of thermal destruction printing, but
The shape of the curd was not changed at all even after 6 months in the active state of field soil or the like.

[0038]

The heat-sensitive recording card produced by the present invention has a print-preserving property of a low-melting-point metal thin film recording medium, and is easily decomposed in a microbial active state such as compost and upland field soil, and is stored in a natural environment. Even if it scatters on the card, the card is decomposed by the action of microorganisms in the environment. Even if it is burnt and discarded, the heat of combustion is low and no toxic gas is generated. Therefore, the card of the present invention is a card having far less adverse effect on the environment than the conventional card.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a thermal recording card of the present invention.

FIG. 2 is a sectional view showing another embodiment of the thermosensitive recording card of the present invention.

FIG. 3 is a sectional view showing another embodiment of the thermal recording card of the present invention.

[Explanation of symbols]

 11 ... Decomposable support 12 ... Colored layer 13 ... Low melting point metal thin film layer 14 ... Heat resistant protective layer 15 ... Magnetic recording layer 16 ... Thermal sensitizing layer 17 ... Paper base material

Claims (8)

[Claims] 1. A thermal recording card in which a colored layer, a thermal recording layer made of a low melting point metal thin film, and a heat-resistant protective layer are sequentially laminated on at least one side of a support, and a decomposable resin is the main component of the support. A heat-sensitive recording card characterized by using a base material. 2. An aliphatic polyester in which the degradable support has a hydroxyalkanoate unit such as 3-hydroxyvalerate, 3-hydroxybutyrate, 3-hydroxycaprolate, or 3-hydroxyheptanoate. The heat-sensitive recording card according to claim 1, wherein 3. The degradable support is represented by the following formula: Embedded image The thermosensitive recording card according to claim 1, which is the chemically synthesized polyester shown in. 4. The heat-sensitive recording card according to claim 1, wherein the degradable support is a composite resin of starch and polyvinyl alcohol. 5. The support having the degradability has an average molecular weight.
A thermoplastic resin containing 10,000 to 1,000,000 polylactic acid or a copolymer of lactic acid and oxycarboxylic acid as a main component,
The thermosensitive recording card according to claim 1, which is composed of decomposable polylactic acid formed by biaxial stretching. 6. The degradable resin according to claim 1 is laminated on one or both sides of a card substrate made of a naturally degradable material such as paper. Thermal recording card. 7. The colored layer is made of a magnetic material, and
The heat-sensitive recording card according to any one of claims 1 to 6, which is colored with a magnetic material. 8. The thermal recording card according to claim 1, wherein the resin of the colored layer is a biodegradable resin.