JP2000136259A - Biodegradable foam sheet for IC card, non-contact type IC card and method for manufacturing the same - Google Patents

Abstract

(57) [Problem] There is a need for a biodegradable foam sheet for an IC card that can be manufactured without damaging an IC chip or the like incorporated therein and that can use a PVC card manufacturing facility as it is. SOLUTION: A biodegradable foam sheet for an IC card mainly comprising crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable foam sheet for an IC card, a non-contact type IC card, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various types of plastic cards have been used in a wide range, and most of them are used for a relatively short time, and are incinerated or discarded. Therefore, from the viewpoint of environmental problems, various cards made of biodegradable plastic have been proposed. This flow is the same for a so-called “IC card” containing an IC chip that has recently attracted attention.

[0003] IC cards are roughly classified into a "contact type IC card" in which contacts with a reader / writer for reading and writing information of the IC chip are exposed on the card surface, and an antenna coil and an IC chip are built in the card. There are two types of "non-contact type IC cards" that can read and further rewrite information of an IC chip with an induced current generated in a coil when the card passes through a magnetic field.

The conventional method of manufacturing a non-contact type IC card is mainly based on an injection molding method in which an IC chip and a lube coil for an antenna are fixed in a card-shaped mold, and then resin is injected and integrated. Had been manufactured. However, when an IC card is manufactured by this method, the IC chip is damaged by the pressure and temperature at the time of injecting the resin, and the cost increases due to the necessity of printing each IC card after molding. ing.

When a non-foamed sheet is used, an IC
In order to avoid damage to the chip, etc., the recess for loading the IC chip, etc. was cut (hereinafter referred to as "scratch processing") and then the IC chip was loaded into the recess, or a window of the size of the IC chip was punched. Later, an IC chip is loaded into the punching window, a sheet for concealing the IC chip is overlapped on one or both sides of the core sheet, and heat-sealed and integrated by a hot press to form a sheet in which the IC chip and the like are embedded. A way to be taken. Even these methods require time and effort. Furthermore, in order to load an IC chip or the like, a recess slightly larger than the size of the IC chip or the like must be formed or a window must be punched out. And the smoothness of the card deteriorates. If the non-foamed sheet is not subjected to counterboring or the like, the IC chip or the like is crushed in the hot pressing step, and the IC chip or the like is damaged.

[0006] On the other hand, many PVC-based magnetic cards currently in use are printed on one or both sides of a core sheet if necessary, and a magnetic tape is sandwiched between transparent oversheets temporarily attached to the front side. A method is used in which a large-sized laminated sheet is hot-pressed at 100 to 180 ° C. and then cut to a required size. The same method can be used for the production of non-contact type IC cards, especially if the production equipment for PVC-based cards can be used as it is, and it is possible to suppress the production cost without installing a new production apparatus.

[0007]

As described above, an IC that can be manufactured without damaging the IC chip or the like incorporated therein and that can use the PVC card manufacturing equipment as it is.
There has been a need for a biodegradable foam sheet for cards.

[0008]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the gist of the present invention resides in a biodegradable foam sheet for an IC card containing crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less as a main component.

In a preferred embodiment of the present invention, the biodegradable foam sheet for an IC card as described above, comprising at least crystalline polylactic acid and an aliphatic polyester having a glass transition temperature of 0 ° C. or less; The ratio between the crystalline polylactic acid and the aliphatic polyester having a glass transition temperature of 0 ° C. or lower is such that crystalline polylactic acid: the aliphatic polyester having a glass transition temperature of 0 ° C. or lower = 90: 10 to 0: 100. The biodegradable foam sheet for an IC card described above.

In another embodiment of the present invention, a non-contact type IC card in which an antenna loop coil and an IC chip are embedded in the biodegradable foam sheet (A); an antenna loop coil and an IC chip A non-contact type IC card in which the above-mentioned biodegradable foamed sheet (A) having embedded therein is used as a core layer and a biodegradable oversheet (B) is laminated on one or both sides thereof; a loop coil for an antenna and an IC chip; Wherein the non-contact type IC card is disposed on a biodegradable sheet; the biodegradable oversheet (B) comprises crystalline polylactic acid as a main component. Contact type IC card; wherein the biodegradable oversheet (B) contains 0 to 40% by weight of an aliphatic polyester having a crystalline polylactic acid as a main component and a glass transition temperature of 0 ° C. or less. The non-contact type IC card that;
A biodegradable sheet on which an antenna loop coil and an IC chip are arranged, wherein the biodegradable sheet is mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. Card; a biodegradable sheet on which an antenna loop coil and an IC chip are arranged, mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less; The non-contact type IC card as described above, wherein the ratio with the aliphatic polyester of 0 ° C. or less is crystalline polylactic acid: the aliphatic polyester having a glass transition temperature of 0 ° C. or less = 80: 20 to 0: 100. (A) / (c)
/ (A), (b) / (a) / (c) / (a), (b) /
(A) / (c) / (a) / (b), (b) / (c) /
(A), (b) / (c) / (a) / (a), (b) /
(C) / (a) / (b), (b) / (c) / (a) /
(A) / (b), (c ') / (a), (c') / (a)
/ (A), (c ') / (a) / (b), or (c')
The non-contact type IC card having a layer structure of / (a) / (a) / (b) ((a): biodegradable foam sheet (A),
(B): biodegradable oversheet (B), (c): biodegradable sheet in which antenna loop coil and IC chip or antenna loop coil and IC chip are arranged, (c ′): antenna A biodegradable sheet on which a loop coil and an IC chip are arranged).

Further, as another embodiment of the present invention, there is provided a biodegradable foam sheet for a non-contact type IC card containing crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less as a main component; A biodegradable sheet on which a loop coil and an IC chip or an antenna loop coil and an IC chip are arranged is sandwiched between biodegradable foam sheets (A) containing crystalline polylactic acid as a main component, and sucked up to a vacuum state. Manufacturing the non-contact type IC card, wherein the air bubbles are crushed by applying heat and pressure in a heated atmosphere, and then the biodegradable foam sheet (A) is cooled while maintaining the crushed air bubbles. Method; Antenna loop coil and IC
A biodegradable sheet on which a chip or a loop coil for an antenna and an IC chip are arranged is made of a biodegradable foamed sheet mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less (A). The biodegradable foamed sheet (A) is provided with a biodegradable oversheet (B) on one or both sides of the biodegradable foamed sheet (A), and heated and pressurized in an atmosphere sucked to a vacuum state to crush bubbles, Cooling the biodegradable foam sheet while maintaining the crushed air bubbles;
The biodegradable sheet on which the antenna loop coil and the IC chip or the antenna loop coil and the IC chip are arranged is biodegraded mainly from crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. After sandwiching the biodegradable foam sheet (A) and the biodegradable oversheet (B) and applying heat and pressure in an atmosphere sucked to a vacuum state to crush bubbles, the biodegradable foam sheet (A) A method for manufacturing a non-contact type IC card, characterized in that cooling is performed while maintaining a state in which bubbles are crushed; a biodegradable sheet on which an antenna loop coil and an IC chip or an antenna loop coil and an IC chip are arranged A biodegradable foam sheet (A) containing crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less as a main component.
And a biodegradable oversheet (B), and a biodegradable oversheet (B) is provided on the remaining surface of the biodegradable foam sheet (A), and heating and pressurizing are performed in an atmosphere sucked to a vacuum state. And then cooling the biodegradable foam sheet (A) while maintaining the crushed state of the air bubbles;
A biodegradable sheet on which an antenna loop coil and an IC chip are arranged and a biodegradable foam sheet (A) containing crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less as a main component are laminated. Applying heat and pressure in an atmosphere sucked up to a vacuum state to crush the air bubbles, and then cooling the biodegradable foam sheet (A) while maintaining the crushed air bubbles. Method for producing contact type IC card; crystalline polylactic acid or glass transition temperature of 0 ° C.
The following biodegradable foamed sheet mainly composed of an aliphatic polyester (A) is sandwiched between a biodegradable sheet on which an antenna loop coil and an IC chip are disposed and a biodegradable oversheet (B), and a vacuum state is obtained. A non-contact type IC wherein the air bubbles are crushed by applying heat and pressure in an atmosphere sucked until the air is absorbed, and then the biodegradable foam sheet (A) is cooled while maintaining the crushed air bubbles. Card manufacturing method.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable foam sheet for an IC card of the present invention uses a foamed aliphatic polyester. Aliphatic polyesters include polylactic acid (60 ° C.) and polyglycolic acid (37 ° C.) having a glass transition temperature of 0 ° C. or higher, specifically, room temperature or higher.
The following aliphatic polyesters include polyhydroxybutyrate and polyhydroxybutyrate / valerate (copolymer) biosynthesized by microorganisms, and polyesters that can be produced by dehydration polymerization of aliphatic dicarboxylic acids and aliphatic diols. For example, there is polybutylene succinate (a polymer of 1,4-butanediol and succinic acid). The biodegradable foam sheet for an IC card of the present invention preferably contains crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less as a main component.

When the biodegradable foam sheet for an IC card of the present invention is hot-pressed at the time of molding a card, the foam becomes a layer in which most of the foamed portion is lost or reduced. However, since the hot pressing is not performed below the thickness of the loop coil for the antenna and the IC chip or the like, the foamed portion remains in the thickness portion. That is, the biodegradable foam sheet (A) of the non-contact type IC card of the present invention is also in the above state when hot pressed. Since the physical properties of the card when formed into a card are derived from the core layer after the disappearance or reduction of the foam together with the over layer, the physical properties of the core sheet after the disappearance of the foam portion or the reduced size are important.

When the polymer constituting the biodegradable foam sheet for an IC card of the present invention, which is the core sheet, is made of only polylactic acid, the rigidity of the polylactic acid which does not crystallize rapidly decreases when the temperature exceeds the glass transition point. However, the card begins to flow and becomes a drawback in use. In order to solve this, it is preferable that the polylactic acid component is crystallized. The crystallized polylactic acid slightly softens even in a temperature range exceeding the glass transition point, but retains rigidity and does not flow.
The crystallinity differs depending on the type and ratio of lactic acid constituting polylactic acid. Poly lactic acid is poly L-lactic acid whose structural unit is L-lactic acid, poly D-lactic acid whose structural unit is D-lactic acid,
There are copolymers containing both L-lactic acid and D-lactic acid.
Poly-L-lactic acid or poly-D-lactic acid has high crystallinity. Copolymers range from amorphous polymers to crystalline polymers depending on the ratio of L-lactic acid and D-lactic acid, and the degree of crystallinity also varies.

The ratio of L-lactic acid to D-lactic acid in the polylactic acid polymer is 100: 0 to 94: 6 or 6:94 to 0: 1.
Outside the range of 00, no crystallization occurs even when heat treatment is performed. Therefore, the crystalline polylactic acid is one in which the ratio of the constituent lactic acid falls within the above range. A sheet having excellent heat resistance can be obtained by the crystalline polylactic acid.

Further, it is preferable from the viewpoint of impact resistance that a biodegradable aliphatic polyester having a glass transition temperature of 0 ° C. or less is mixed with the sheet made of crystalline polylactic acid. A component that is flexible at least at room temperature is required to improve brittleness, and a melting point of at least 80 ° C. or more is required to suppress a decrease in rigidity due to components mixed even when the temperature exceeds the glass transition temperature of polylactic acid. Having an aliphatic polyester is more preferred. Examples of a material that can bring about such an effect include a crystalline aliphatic polyester.

The amount of the above-mentioned aliphatic polyester having a glass transition temperature of 0 ° C. or lower is determined from the viewpoint of impact resistance in terms of crystalline polylactic acid: aliphatic polyester having a glass transition temperature of 0 ° C. or lower.
Preferably, the ratio is 90:10 to 0: 100 (weight ratio). That is, an aliphatic polyester having a glass transition temperature of 0 ° C. or lower may be the main component of the biodegradable foam sheet for an IC card. If the content is too small, the effect of impact resistance cannot be sufficiently exhibited.

As described above, it has been described that the biodegradable foam sheet for an IC card of the present invention contains polylactic acid.
There is no particular limitation, and it may be composed only of an aliphatic polyester having a glass transition temperature of 0 ° C. or less. However, aliphatic polyesters having these properties generally have a low elastic modulus and lower the overall waist of the card,
This must be taken into account. Further, when a transparent oversheet is bonded to the surface of the core sheet as described later, the oversheet is preferably composed mainly of polylactic acid from the viewpoint of transparency, unless an adhesive is used. It is necessary to perform heat fusion with a hot press. Therefore, since the main component of the oversheet is polylactic acid, it is more advantageous to include the polylactic acid component also in the core sheet (the biodegradable foamed sheet for an IC card of the present invention) from the viewpoint of heat-fusing property. It is preferable to contain 20% by weight or more. If it is less than this, sufficient heat-sealing strength cannot be obtained, and bonding cannot be performed only by hot pressing. In that case, it is recommended to use an adhesive or the like.

The biodegradable foam sheet for an IC card of the present invention incorporates an antenna loop coil, an IC chip, and the like. Therefore, the expansion ratio of the foam sheet is set so that the antenna loop coil, the IC chip, and the like can be embedded. The value of the foaming ratio is specifically, as long as the foamed sheet is foamed such that the thickness of the foamed sheet is equal to or greater than the thickness of the antenna loop coil or the chip, etc., but it is not particularly limited.
Usually, it is 1.5 or more, preferably twice or more. If the expansion ratio of the sheet is low, the sheet is hard, and if the thickness of the IC chip or the like to be used is large, there is a risk of damaging the IC chip or the like during pressing. In addition, the surface of the card may be distorted by the IC chip, resulting in poor smoothness. The upper limit is not particularly limited, but is determined by the kind of the aliphatic polyester used, the melt viscosity thereof, the kind and amount of the foaming agent, and the like, as long as the physical properties do not deteriorate.

The type of the foaming agent to be added is not particularly limited, and any compound used in ordinary resin processing can be used. The amount of the foaming agent is selected so that a desired expansion ratio can be obtained. Ammonium carbonate, azodicarboxylic acid amide-based compounds, dinitrosopentamethylenetetramine and the like are used as the pyrolytic foaming agents, and lower alkanes such as propane, butane, n-pentane and isopentane and dichlorodifluorocarbon are used as the volatile foaming agents. Halogenated hydrocarbons such as methane, tetrafluoroethane, trichlorofluoromethane, and methyl chloride, and carbon dioxide and nitrogen can be used. Further, the sheet may be foamed by forcibly injecting an inert gas into the molten resin by an extruder. In addition, it is also possible to use a foaming assistant such as a metal oxide or a cell regulator such as calcium silicate.

In addition, a plasticizer, a heat stabilizer, an anti-blocking agent, an ultraviolet absorber, a concealing material, a filler and the like may be contained as long as the characteristics of the sheet of the present invention are not hindered.
The non-contact type IC card of the present invention is obtained by embedding a loop coil for an antenna and an IC chip in the biodegradable foam sheet for an IC card.

The embedding of the antenna loop and the IC chip may be performed according to a known method. For example, the IC chip or the like is temporarily attached and fixed on a biodegradable sheet or a biodegradable foam sheet for an IC card with an adhesive. Then, a biodegradable foam sheet for an IC card and / or an oversheet are stacked thereon and hot-pressed. The adhesive is not particularly limited as long as it can be temporarily fixed, but in consideration of biodegradability, it has biodegradability from natural rubber-based, starch-based and protein-based natural products. Synthetic polymer polyvinyl alcohol and the like are preferred. The configuration of the hot press and the card will be described later.

In the present invention, the antenna loop and I
The C chip or the like may be directly incorporated in the biodegradable foam sheet for an IC card. However, the C chip or the like is adhered to or incorporated in advance in the biodegradable sheet, and is combined with the biodegradable foam sheet for an IC card. May be. If the antenna loop and the IC chip are bonded to the biodegradable sheet, the antenna loop and the IC chip
It is preferable to combine them so as to be in contact with the biodegradable foam sheet for C card.

Further, in the present invention, the number of foamed sheets may be one, but may be two or more. If there are two or more layers,
The biodegradable sheet having the antenna loop and the IC chip or the like or the antenna loop and the IC chip or the like may be incorporated between two or more biodegradable foam sheets for an IC card. The non-contact type IC card of the present invention may be provided with an oversheet outside the foam sheet. The oversheet may be provided on one side or both sides of the foam sheet.

It is preferable that the biodegradable sheet on which the loop coil for the antenna and the IC chip are arranged is mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. The ratio of crystalline polylactic acid to the aliphatic polyester having a glass transition temperature of 0 ° C. or less is such that the ratio of the crystalline polylactic acid to the aliphatic polyester having a glass transition temperature of 0 ° C. or less is 80:20 to 0: 100 (weight ratio). ) Is more preferable. That is, an aliphatic polyester having a glass transition temperature of 0 ° C. or lower may be the main component of the biodegradable sheet. If the content of the aliphatic polyester resin is too small, the impact resistance is not excellent, and cracks and cracks are easily caused by impact.

The oversheet is preferably made of polylactic acid from the viewpoint of transparency, and particularly preferably crystalline polylactic acid. Further, it is preferable to mix the aliphatic polyester contained in the core sheet from the viewpoint of increasing the heat bonding strength with the core sheet. By the mixing, the fusion of the polylactic acid contained in the over layer and the core layer and the fusion of the aliphatic polyester contained in the over layer and the core layer occur simultaneously, so that the fusion strength can be increased. When the polylactic acid is not stretched (oriented), it is preferable to mix an aliphatic polyester from the viewpoint of improving impact resistance as described above.
The mixing amount of the aliphatic polyester is 0 to 40% by weight.
Above 40% by weight, transparency is lost.

In the case where the aliphatic polyester is not contained in the oversheet or in the region where the aliphatic polyester is small, the polylactic acid is preferably oriented and crystallized. Polylactic acid is disclosed in JP-A-7-205278,
Stretching increases the strength of the sheet and improves its brittleness. Further, by crystallizing, the heat resistance is improved, and a film having a small heat shrinkage is obtained, which is superior in a bonding process by a hot press. Furthermore, since other aliphatic polyesters do not need to be contained or can be suppressed to a small amount, a sheet excellent in transparency can be obtained.

The method for producing polylactic acid used for the biodegradable foam sheet for an IC card of the present invention, the biodegradable sheet of the present invention (a biodegradable sheet in which an antenna loop coil and an IC chip are arranged) and an oversheet are particularly limited. However, there are optional methods such as a polymerization method and a ring-opening polymerization method. As the monomer, L-lactic acid, D-lactic acid or a mixture thereof is used in the polymerization method and the cyclic dimerization of lactic acid. L-lactide, D-lactide, DL-lactide or mixtures thereof, which are in the form of a body, are used in the ring-opening polymerization process. Also, for the purpose of increasing the molecular weight, a small amount of a chain extender during polymerization,
For example, a diisocyanate compound, an epoxy compound, an acid anhydride and the like can be used.

The preferred weight average molecular weight of polylactic acid is 6
If it is too small, it will be difficult to develop practical physical properties, and if it is too large, the melt viscosity will increase and molding workability will be poor. The polylactic acid has a glass transition temperature of 60 ° C. and the melting point varies depending on the ratio of L-lactic acid and D-lactic acid, but has no melting point or is in the range of 100 to 200 ° C.

In the non-contact type IC card of the present invention, a crystalline aliphatic polyester having a low glass transition temperature, which is another component constituting the core layer or the over layer, is one capable of improving the impact resistance of polylactic acid, 60 ° C. There is no particular limitation as long as the rigidity is exceeded, and two or more kinds may be mixed. Usually, the glass transition temperature is 0 ° C. or lower, preferably −
Those having a temperature of 20 ° C. or less are used. In order to maintain rigidity exceeding 60 ° C., the melting point (flow starting temperature) is 80 ° C.
Having the above is effective.

The above-mentioned aliphatic polyesters which are currently under development include polyhydroxybutyrate and polyhydroxybutyrate which are biosynthesized by microorganisms.
Valerate (copolymer) and the like. Further, there is a polyester which can be produced by dehydration polymerization of an aliphatic dicarboxylic acid and an aliphatic diol, for example, polybutylene succinate (a polymer of 1,4-butanediol and succinic acid).

As the aliphatic polyester produced by microorganisms represented by polyhydroxybutyrate, an aliphatic polyester biosynthesized by acetyl coenzyme A (acetyl CoA) in cells such as alkaligenes eutrophas is known. I have. This aliphatic polyester
It is mainly poly-β-hydroxybutyric acid (poly 3HB), but in order to improve the practical properties as a plastic, the fermentation process is devised and the valeric acid unit (H
V), and the copolymerization ratio of poly (3HB-co-3HV) is generally 0 to 40%, and Tm is 1 in this range.
30-165 ° C. Instead of HV, 4HB may be copolymerized, or long-chain hydroxyalkanoate may be copolymerized.

A polymer comprising an aliphatic carboxylic acid component and an aliphatic alcohol component represented by polybutylene succinate is composed of the following units. The aliphatic diol unit, which is one of the structural units of the polymer, is selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. The aliphatic dicarboxylic acid unit, which is one of the structural units, includes succinic acid, adipic acid, suberic acid, sebacic acid,
It is selected from dodecane diacid and the like.

There is no particular limitation on the method for producing the above-mentioned polymer comprising an aliphatic diol unit and an aliphatic dicarboxylic acid unit.
Any method such as a housing polymerization method, a ring-opening polymerization method, or a biological method can be performed. As the monomer, a mixture of at least one of the above-mentioned diols and dicarbic acids is used for the housing polymerization method. And a mixture of at least one or more diols and dicarboxylic acids, respectively,
Examples of oxiranes that are ring-closing compounds of diols and carboxylic acids include, for example, ethylene oxide, propylene oxide, tetrahydrofuran, and the like.
Examples of the acid anhydride include succinic anhydride and adipic anhydride. At the time of the polymerization, a crystalline aliphatic polyester having an arbitrary composition can be obtained by selecting a mixing ratio of the monomers. For the purpose of increasing the molecular weight, a small amount of a chain extender, for example, a diisocyanate compound, an epoxy compound, an acid anhydride or the like can be used during the polymerization.

The preferred weight average molecular weight of the above aliphatic polyester is 50,000 to 1,000,000. If it is too small, the melt tension is low, and it is difficult to take out the sheet when melt extruded. If it is too large, the melt viscosity is too high. Poor workability.
The glass transition point and melting temperature of the aliphatic polyester are:
Although it varies depending on the composition and molecular weight, it is usually −60 to 0 ° C.
And about 80 to 170 ° C.

The method for forming a sheet to be used as a core layer or an over layer of the non-contact type IC card of the present invention is carried out by using polylactic acid and / or an aliphatic polyester having a glass transition point of 0 ° C. or lower, if necessary. Or together with additive ingredients
It is also possible to adopt a method in which an extruder is used to directly produce a sheet, or a method in which the extruder is once extruded and cut into strands to form pellets, and then is again introduced into the extruder to produce a sheet. Actually, in consideration of the molecular weight reduction due to decomposition in the extruder, the polylactic acid and the aliphatic polyester are sufficiently dried in advance to remove water, and then melted in the extruder. The melt extrusion temperature is appropriately selected in consideration of the melting temperature and composition of the polymer in the composition.
It is selected from the range of 250 ° C. The production method of foam sheet is
As described above, a predetermined amount of the blowing agent is mixed and melted in the extruder, and at the same time, an inert gas is generated. In the extruder, the bubbles are suppressed and small because they are under high pressure, but they are placed under atmospheric pressure where the molten resin is discharged from the die, so that the bubbles become large in the molten resin and a foam can be obtained.

The polymer composition melt-formed into a sheet, including a foam sheet, is cooled by contact with a rotating casting drum. The temperature of the casting drum varies depending on the type and composition of the polymer in the composition, but is usually preferably 60 ° C. or lower. At higher temperatures, the polymer sticks to the casting drum and cannot be pulled off. When the sheet is stretched, it is preferable that the polylactic acid portion be made substantially amorphous by rapid cooling so that crystallization of the polylactic acid portion is promoted and spherulites do not develop.

Next, the case where the sheet is stretched and heat-treated will be described. The stretching ratio of the sheet is, for example, longitudinal (longitudinal).
The stretching temperature is appropriately selected in the range of 1.5 to 5 times, preferably 2 to 4 times in the direction and the lateral (width) direction, and the stretching temperature is appropriately in the range of 50 to 90 ° C, preferably 55 to 80 ° C. The stretching step is a roll stretching in which the sheet is stretched between two rolls having a difference in peripheral speed, and / or a tenter stretching in which the gap between the rows of the clips is extended while the sheet is gripped with a clip using a tenter. Done by In the case of biaxial stretching, either simultaneous or sequential stretching method may be used. In the case of the sequential biaxial stretching method, the in-plane orientation degree Δn of the sheet after the first-stage stretching is 3.0 × 10 ⁻³ to 30.
× 10 ⁻³ , preferably 5.0 × 10 ⁻³ to 30 × 10
^-3 is preferred. If it is smaller than this range,
If the tensile strength and elongation are insufficient or large, problems such as breakage of the sheet during the second-stage stretching occur.

The tenter stretching method is advantageous because the sheet can be heat-set in the tenter after the sheet is stretched by the tenter. In the heat setting, for example, the heat shrinkability of the sheet can be controlled (suppressed) by performing a heat treatment within a temperature range from the glass transition point to the melting point (Tm) for 3 seconds or more.

The non-contact IC card of the present invention comprises: (1) two or more biodegradable sheets on which an antenna loop coil and an IC chip or an antenna loop coil and an IC chip are arranged; In a state where the foamed sheet is sandwiched and sucked in a vacuum, the foam is heated and pressed to crush bubbles in the foamed sheet, cooled to room temperature, and punched out in a card shape. (2) Loop coil for antenna and IC chip or antenna The biodegradable sheet on which the loop coil and the IC chip are arranged is sandwiched between two or more biodegradable foam sheets, and a biodegradable oversheet is provided on one or both sides of the biodegradable foam sheet. In the state of being sucked,
Heat and apply pressure to crush bubbles in the foamed sheet, cool to room temperature, and punch out into a card shape. (3) Biodegradation with antenna loop coil and IC chip or antenna loop coil and IC chip arranged The biodegradable foam sheet and the biodegradable oversheet,
In the state of being sucked in a vacuum, heating and applying pressure to crush bubbles in the foamed sheet, cool to room temperature, and punch out into a card shape. (4) Loop coil for antenna and IC chip, or loop coil for antenna and IC The biodegradable sheet on which the chip was placed was sandwiched between the biodegradable foam sheet and the biodegradable oversheet, the biodegradable oversheet was provided on the remaining surface of the biodegradable foam sheet, and the vacuum was sucked. In the state, heat and pressure are applied to crush bubbles in the foamed sheet, cool to room temperature, and then punch out into a card shape. (5)
The biodegradable sheet on which the loop coil for the antenna and the IC chip are arranged and the biodegradable foam sheet are stacked, and in a state of being suctioned by vacuum, heating and pressure are applied to crush bubbles in the foam sheet. After cooling down, punch into a card shape,
Or (6) sandwich the biodegradable foam sheet between the biodegradable sheet and the biodegradable oversheet on which the antenna loop coil and the IC chip are arranged, and apply heat and pressure while being sucked in vacuum. Crush bubbles in the foam sheet,
It is obtained by punching into a card shape after cooling to room temperature.

The loop coil for the antenna, the IC chip, and the like may be made into one set, and a large number of sets of IC chips may be arranged on the polymer layer at equal intervals in consideration of a desired card size and the like. The loop diameter of the coil and the number of windings of the loop coil for the antenna can be appropriately selected according to the usage of the card.

The thickness of the card base material of the present invention varies depending on the application, but in the case of a cash card or a credit card, a thick one of about 500 μm to 900 μm, and in the case of a telephone card or a prepaid card. Used is as thin as about 50 to 350 μm.
The thickness of the over layer is 20 to 140 μm in a thick one,
Even a thin one is preferably about 20 to 100 μm, but there is no particular limitation.

[0043]

The present invention will be described below in detail with reference to examples. The measurements and evaluations shown in the examples were performed under the following conditions. (1) Measurement of glass transition temperature Tg and melting point Tm of polylactic acid and aliphatic polyester were measured using a differential scanning calorimeter DSC-7 manufactured by Perkin Elmer. 10 mg of the sample was set, and the heating rate was 10
The temperature was raised to 200 ° C. at a rate of ° C./min, and the temperature was maintained for 2 minutes to completely melt the sample. At that time, the temperature drop rate is 10 ° C
The endothermic peak temperature of the melting that appears on the DSC curve when the temperature was decreased at a rate of / m was defined as the melting point Tm, and determined based on JIS K7122. The temperature was further lowered, lowered to -60 ° C. once, kept for 2 minutes, and raised again at 10 ° C./min.
21, the intermediate value of the transition curve is calculated as the glass transition temperature T.
g. In addition, liquid nitrogen was used as a cooling medium for performing the measurement at 0 ° C. or lower.

(2) Damage to IC Chips, etc. The IC chips and the like in the card laminated and bonded by the hot press are correctly installed, bent or broken, and the IC chips and the like are taken out and visually observed. did.良好 indicates good, and × indicates damage.

(3) Sharpness of the Printed Part After the characters / patterns printed on the surface (back surface) of the over layer which is in contact with the core layer were formed into a card, it was visually observed whether or not it was clearly visible through the over layer. Those that are clearly visible are represented by ○, and those that tend to be cloudy are represented by x.

(4) Heat resistance Credit card standard with magnetic stripe JISX63
When immersed in warm water at 60 ° C. for 5 minutes according to No. 10, the surface of the card was observed to change and shrink. Further, the same evaluation was performed in warm water at 80 ° C. This test is an indicator of the heat resistance of the card. Good results were indicated by ○, and problems were indicated by ×.

(5) Impact strength Credit card standard with magnetic stripe JISX63
The impact strength was measured according to 10. When the card was placed on a solid horizontal plate and a 500 g steel ball was dropped from a height of 30 cm onto the card, the card was marked with "O" if the card did not crack or crack, and "X" was marked.

(6) Fusing property of the over layer and the core layer The card laminated and bonded by the hot press is cut out, hooked with a nail, peeled off, and pulled with both hands.
The condition of peeling was checked. A substance that was firmly fused was represented by ○, a slightly weak substance was represented by Δ, and a substance that could be easily peeled was represented by X.

(7) Comprehensive Evaluation From the evaluation results of the above (2) to (6), those having at least one item marked with x are marked with x, and those other than those are marked with o. The ones marked with X are those with low practicality, and those with ○ represent high practicality.

[Production of Sheet] Production Example 1: Sheet No. Production of 1 Polylactic acid (trade name: Lacti 100) obtained by ring-opening polymerization of lactide of L-lactic acid (D-lactic acid content: 1% or less)
0, manufactured by Shimadzu Corporation) after sufficiently drying to remove moisture, cylinder temperature 210 ° C., die temperature 200 ° C.
Was extruded onto a cooling roll having a surface temperature of 58 ° C. using a T-die extruder to obtain a sheet having a thickness of 100 μm.

Production Examples 2, 3: Sheet No. Manufacture of 2, 3 Polylactic acid (Lacty 1000) and polybutylene succinate / adipate copolymer (trade name: Bionole # 30)
01, manufactured by Showa Polymer Co., Ltd.) to be 20% by weight and 50% by weight. It was cut into chips with a blade. After thoroughly drying this chip to remove water,
Using a T-die extruder at a cylinder temperature of 210 ° C. and a die temperature of 200 ° C., the sheet was extruded onto a cooling roll having a surface temperature of 58 ° C. to obtain a sheet having a thickness of 100 μm.

Production Example 4: Sheet No. Production of Sheet No. 4 A transparent sheet made of polylactic acid and having a thickness of about 700 μm was obtained in the same manner as in the production of Example 1. This sheet was preheated by a metal roll, and then stretched 2.5 times in the longitudinal direction between rolls having a difference in peripheral speed while being heated by an infrared heater. Subsequently, the sheet was transversely stretched 3.0 times with a tenter and subsequently heat-treated in the tenter to obtain a stretched and heat-set sheet having a thickness of 100 μm. The conditions for stretching and heat treatment were as follows. Longitudinal stretching: stretching temperature 75 ° C., stretching ratio 2.5 times Transverse stretching: stretching temperature 72 ° C., stretching ratio 3.0 times Heat treatment: heat treatment temperature 130 ° C., heat treatment time 20 seconds

Comparative Example 1: Sheet No. Production of 5 80% by weight of polylactic acid (Lacty 1000) was mixed with 20% by weight of Bionole # 3001, and further rutile-type titanium dioxide (trade name: TR-700) Fuji Titanium Industry Co., Ltd.
Was extruded into a strand shape while being melt-kneaded with a coaxial twin screw extruder at a cylinder temperature of 210 ° C. and a die temperature of 200 ° C., and cut into chips by a rotary blade. After sufficiently drying the chips to remove water, the chips were extruded onto a cooling roll having a surface temperature of 50 ° C. using a T-die extruder at a cylinder temperature of 210 ° C. and a die temperature of 200 ° C. to obtain a sheet having a thickness of 280 μm. Was.

Examples 1-4: Sheet No. Production of 6-9 Polylactic acid (Lacty 1000) and Bionole # 300
1, and titanium oxide were mixed in the proportions shown in Table 2, extruded into a strand shape while melting and kneading with a coaxial twin screw extruder at a cylinder temperature of 210 ° C and a die temperature of 200 ° C, and cut into chips with a rotary blade. did. After the chips were sufficiently dried to remove water, they were put into an extruder together with the number of blowing agents shown in Table 2, and the cylinder temperature was set to 200.
Surface temperature of 4 ° C using a T-die at a die temperature of 190 ° C.
The sheet was extruded on a cooling roll at 5 ° C. to obtain a 550 μm thick sheet. The expansion ratios were all set to be approximately twice.

Example 5: Sheet No. Production of Lacty 1000 Instead of Lacty 1000, as shown in Table 1, polylactic acid containing 8% of D-lactic acid in the polymer component was used. A foam sheet was produced in the same manner as in No. 6. This polylactic acid is a polymer that does not crystallize.

Examples 6 to 13 and Comparative Example 2: Molding (stacking) of card The obtained foamed core sheet was cut into a width of 30 cm and a length of 40 cm, and a copper wire having a wire diameter of 0.15 mm was turned four times four times. A loop coil for a wound antenna and an IC chip having a size of 5 m × 5 mm and a thickness of 0.35 mm are arranged at regular intervals in consideration of a desired card size, and temporarily fixed with a cyanoacrylate instant adhesive. A foam core sheet of the same size was placed so as to sandwich the IC chip and the like. 30cm x 4 with an image printed on the back using a silk printing machine
These foamed core sheets were sandwiched between two 0 cm oversheets, and one sheet on each of both sides thereof, and a total of two chromium-plated steel sheets were sandwiched. Then, in an atmosphere evacuated to a vacuum, at a temperature described in Table 3 and a pressure of 10 kg / c.
under the condition of m ^2, air bubbles in the foam sheet was maintained in this state until collapsing completely.

Thereafter, while keeping the state in which the bubbles were crushed, the mixture was cooled to room temperature, cut into a card shape, and a non-contact type IC card having a three-layer structure of over layer / core layer / over layer shown in Table 3 was obtained. Was. Crystallization of the polylactic acid in the over layer and the core layer proceeds in this hot pressing step, resulting in a card having substantially improved heat resistance. Combinations of the oversheet and the core sheet are as shown in Table 3. Table 3 also shows the evaluation results of the obtained cards.

However, in Examples 7 and 9, an adhesive is used for laminating the oversheet and the core sheet. In the core sheet used in Example 7, the main component resin is Bionole #
At a temperature exceeding 100 ° C., a sheet made of 3001 alone melts and the core layer starts to flow, so that the temperature cannot be increased. At a temperature of 100 ° C. or less, sufficient adhesive strength could not be obtained, so an adhesive was used. Further, in Example 9, when the temperature was raised to 160 ° C. at which the fusion was possible, the heat shrinkage of the oversheet was increased, and an adhesive was used in order to obtain a card having large distortion.

8 parts by weight of polyisocyanate compound Desmodur L-75 (manufactured by Bayer) is mixed with 100 parts by weight of a copolymer polyester hot melt adhesive Vylon 300 (manufactured by Toyobo Co., Ltd.) on both sides of the core layer. The toluene / MEK solution was applied and dried sufficiently at room temperature to evaporate the solvent, and the thickness of the adhesive was adjusted to about 3 μm. Next, a card was obtained by sandwiching the two overlayers shown in Examples 2 and 4 at a press temperature of 90 ° C. and 110 ° C., respectively, and a pressure of 5 kg / cm ² .

[0060]

[Table 1]

[0061]

[Table 2]

* 1: Polylactic acid (C) containing about 8% of D-lactic acid and Bionore # 3001 (B) in a ratio of 80/20. * 2: Biaxially stretched and oriented sheet 1 to 4, ratio 1, and actual 1 to 5 in Table 2 mean Production Examples 1 to 4, Comparative Example 1, and Examples 1 to 5, respectively. The blowing agent in Table 2 is azodicarboxylic amide.

[0063]

[Table 3]

In Table 3, Reals 6 to 13 represent Examples 6 to 13, and a ratio of 2 means Comparative Example 2. As shown in Table 3, in Comparative Example 2, since the IC chip and the like were sandwiched between the hard core sheets, the IC chip and the like in the completed card were slightly bent and damaged. When the foamed sheet was used, the IC chip and the like were not damaged. From the above results, it was proved that the biodegradable foam sheet for an IC card of the present invention can be manufactured without damaging an IC chip or the like.

[0065]

According to the biodegradable foam sheet for an IC card of the present invention, an IC card can be manufactured without damaging an IC chip and the like, and a PVC card manufacturing facility can be used as it is.

Continued on the front page F term (reference) 2C005 MA10 NA09 PA01 PA18 PA40 RA04 TA22 4F074 AA68A AB02 BA04 BA13 BA16 BA36 BA37 BA38 BA39 BA53 BA55 BA57 BA58 CA24 CA29 CC04Z CC32Z CC34Y CC34Z CC62 CD01 CE02 DA24 DA54 DA59 4F41 BA41BA06 BA13BA06 DJ01A DJ01C EC14 EH012 EJ172 EJ242 EJ422 EJ502 GB43 JA05A JA05C JA11A JA11C JC00 JC00B YY00A YY00C 5B035 AA04 AA08 BA03 BB09 BB12 CA01 CA03 CA23

Claims (17)

[Claims] 1. A biodegradable foam sheet for an IC card comprising crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or lower as a main component. 2. The biodegradable foam sheet for an IC card according to claim 1, comprising at least crystalline polylactic acid and an aliphatic polyester having a glass transition temperature of 0 ° C. or less. 3. A crystalline polylactic acid having a glass transition temperature of 0 ° C.
The ratio with the following aliphatic polyester is crystalline polylactic acid: an aliphatic polyester having a glass transition temperature of 0 ° C. or less =
3. The biodegradable foam sheet for an IC card according to claim 1, wherein the ratio is 90:10 to 0: 100. 4. A non-contact type IC card in which an antenna loop coil and an IC chip are embedded in the biodegradable foamed sheet (A) according to claim 1. 5. The biodegradable foam sheet (A) according to claim 1, wherein a loop coil for an antenna and an IC chip are embedded as a core layer, and a biodegradable oversheet is provided on one or both surfaces thereof. Non-contact IC with (B) laminated
card. 6. The non-contact type IC card according to claim 4, wherein the loop coil for the antenna and the IC chip are arranged on a biodegradable sheet. 7. The biodegradable oversheet (B) comprises crystalline polylactic acid as a main component.
7. The non-contact IC card according to any one of 6. 8. The biodegradable oversheet (B) contains 0 to 40% by weight of an aliphatic polyester whose main component is crystalline polylactic acid and whose glass transition temperature is 0 ° C. or lower. 7. A non-contact IC according to any one of items 4 to 6.
card. 9. The biodegradable sheet on which an antenna loop coil and an IC chip are arranged is mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. Item 9. A non-contact IC card according to any one of Items 4 to 8. 10. A biodegradable sheet on which an antenna loop coil and an IC chip are arranged, wherein the biodegradable sheet is mainly composed of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less, and is composed of crystalline polylactic acid and glass. The ratio with the aliphatic polyester having a transition temperature of 0 ° C. or lower is crystalline polylactic acid: the aliphatic polyester having a glass transition temperature of 0 ° C. or lower = 80:
20: 0: 100: 9-4.
A non-contact IC card according to any one of the above. 11. (a) / (c) / (a), (b) /
(A) / (c) / (a), (b) / (a) / (c) /
(A) / (b), (b) / (c) / (a), (b) /
(C) / (a) / (a), (b) / (c) / (a) /
(B), (b) / (c) / (a) / (a) / (b),
(C ') / (a), (c') / (a) / (a),
(C ') / (a) / (b) or (c') / (a) /
The non-contact IC card according to any one of claims 1 to 9, having a layer structure of (a) / (b). (A): a biodegradable foam sheet (A) (b): a biodegradable oversheet (B) (c): a raw sheet in which an antenna loop coil and an IC chip or an antenna loop coil and an IC chip are arranged. Degradable sheet (c '): Biodegradable sheet on which the antenna loop coil and IC chip are arranged 12. A biodegradable sheet on which an antenna loop coil and an IC chip, or an antenna loop coil and an IC chip are arranged, is mainly made of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. After sandwiching the biodegradable foam sheet (A) as a component and applying heat and pressure in an atmosphere sucked to a vacuum state to crush bubbles, the bubbles of the biodegradable foam sheet (A) are crushed. A method for manufacturing a non-contact type IC card, wherein cooling is performed while maintaining a state. 13. A biodegradable sheet on which an antenna loop coil and an IC chip, or an antenna loop coil and an IC chip are arranged, is made of crystalline polylactic acid or aliphatic polyester having a glass transition temperature of 0 ° C. or lower. A biodegradable foam sheet (A) as a component is sandwiched between the biodegradable foam sheets (A), and a biodegradable oversheet (B) is provided on one or both sides of the biodegradable foam sheet (A). A method for manufacturing a non-contact type IC card, comprising: applying pressure to crush air bubbles; and cooling the biodegradable foam sheet while maintaining the crushed air bubbles. 14. A biodegradable sheet on which an antenna loop coil and an IC chip, or an antenna loop coil and an IC chip are arranged, is made of crystalline polylactic acid or aliphatic polyester having a glass transition temperature of 0 ° C. or lower. After sandwiching the biodegradable foam sheet (A) and the biodegradable oversheet (B) as components and applying heat and pressure in an atmosphere sucked to a vacuum state to crush bubbles, the biodegradable foam A method for manufacturing a non-contact type IC card, characterized in that the sheet (A) is cooled while maintaining a state in which bubbles are crushed. 15. A biodegradable sheet on which an antenna loop coil and an IC chip, or an antenna loop coil and an IC chip are arranged, is mainly made of crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or less. A biodegradable foam sheet (A) as a component is sandwiched between a biodegradable oversheet (B) and a biodegradable oversheet (B) is provided on the remaining surface of the biodegradable foam sheet (A) to form a vacuum. A non-contact type IC wherein the air bubbles are crushed by applying heat and pressure in an atmosphere sucked until the air is absorbed, and then the biodegradable foam sheet (A) is cooled while maintaining the crushed air bubbles. Card manufacturing method. 16. A biodegradable sheet on which an antenna loop coil and an IC chip are arranged, and a biodegradable foam sheet containing crystalline polylactic acid or an aliphatic polyester having a glass transition temperature of 0 ° C. or lower as a main component. A) is superimposed on, and after applying heat and pressure in an atmosphere sucked up to a vacuum state to crush the air bubbles, cooling the biodegradable foam sheet (A) while maintaining the crushed air bubbles. A method for producing a non-contact type IC card. 17. A biodegradable foamed sheet (A) containing crystalline polylactic acid or an aliphatic polyester having a glass transition point of 0 ° C. or less as a main component is biodegraded by disposing an antenna loop coil and an IC chip. After sandwiching between the biodegradable sheet and the biodegradable oversheet (B) and applying heat and pressure in an atmosphere sucked to a vacuum state to crush bubbles, the cells of the biodegradable foam sheet (A) are crushed. A method for manufacturing a non-contact type IC card, wherein cooling is performed while maintaining a state.