JPH0896421A - Optical card - Google Patents

Abstract

PURPOSE: To obtain an optical card not causing warpage or cracking due to bending and excellent in scuffing and wear resistances while using polycarbonate resin as the material of the transparent protective layer. CONSTITUTION: Polycarbonate resin is used as the material of a transparent protective layer 1 and a middle layer 6 of >=20μm thickness made of a radiation- curing resin having <=12% shrinkage is formed on the protective layer 1. Since the radiation-curing resin having <=12% shrinkage can suppress the warpage of the protective layer 1 even in the case of thick coating, coating in >=20μm thickness required to make the middle layer 6 independent of the under protective layer 1 at the time of a pencil hardness test is enabled and pencil hardness of H to 2H is ensured by coating in >=20μm thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical card used for credit cards, cash cards, medical cards and the like.

[0002]

2. Description of the Related Art Conventionally, as a card-type recording medium, an optical card having a storage capacity larger than that of a magnetic card or an IC card has been developed. The recording method of this optical card includes a read-only (ROM) type, a write-once (DRAW) type,
There is an erasing and writing (E-DRAW) type, and a recording medium and a configuration are being studied for each.

Such an optical card basically has a layer structure as shown in FIG. In the figure, 1 is a transparent protective layer as a support, which has a high transmittance in the wavelength range of the light source used for recording and reproduction, and does not cause deformation or deterioration in the subsequent steps, and has a mechanical strength and an optical characteristic. There is no particular limitation as long as it satisfies the requirements, and generally, a polycarbonate resin, an acrylic resin, a urethane resin, an epoxy resin, a polyvinyl chloride resin, a polyolefin resin, a styrene polycarbonate blend resin or the like is used.
Reference numeral 2 is a pattern layer provided on the lower surface of the transparent protective layer 1 by the 2P method, and is provided with concave and convex grooves to be tracks.
Reference numeral 3 is an optical recording material layer provided so as to cover the concave and convex grooves of the pattern layer 2. For example, in the DRAW type, an inorganic material made of a low melting point metal such as tellurium, bismuth, or aluminum, and an alloy thereof, an anthraquinone-based material, a naphthoquinone-based material,
Triphenylmethane type, carbocyanine type, merocyanine type, xanthene type, azo type, azine type, thiazine type,
It is generally formed of an organic dye including an organic dye such as an oxazine-based or phthalocyanine-based dye. In the case of the ROM type, it is formed in a form in which information is recorded in advance by a highly reflective metal such as aluminum. 4 is a card substrate, and an adhesive layer 5
The optical recording member having the above-mentioned structure is supported via the.
As described above, the optical card has a structure in which the optical recording material layer 3 is sandwiched between the transparent protective layer 1 on the front side and the card base material 4 on the back side. In addition, in order to prevent the surface from being scratched when carrying or using the card, and to improve the durability of the card and the reliability of writing and reading accuracy, the transparent protective layer 1 may be used as necessary. The surface hardened layer is provided on the front side. The surface-cured layer is usually formed of a radiation-curable resin in most cases.

[0004]

By the way, in the optical card as described in the prior art, it is desired to use a polycarbonate resin for the transparent protective layer which is the support of the optical recording material layer. That is, the polycarbonate resin is low in price, has no water absorbency, and has advantages such as excellent bending suitability without warping or cracking. However, since the polycarbonate resin has a low hardness against scratches (pencil hardness), when it is used as a transparent protective layer, it is necessary to provide a surface-hardened layer in order to improve scratch resistance. In this case, when a surface-cured layer is formed on the transparent protective layer using a normal radiation-curable resin having a large shrinkage ratio, shrinkage and warpage may occur during curing by radiation, and further cracks due to bending may occur. 15 μm because there is
It cannot be formed with the above thickness. As described above, when the thickness of the surface-hardened layer is at most about 15 μm, it is affected by the underlying transparent protective layer when a pencil hardness test is performed, and only a hardness of F to HB is obtained, and the scratch resistance is sufficient. There is a problem that a surface hardened layer having a hardness of H or higher cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is an optical card using a polycarbonate resin for a transparent protective layer, which has excellent scratch resistance. The purpose of the present invention is to provide an optical card that does not warp or crack when bent.

[0006]

In order to achieve the above object, an optical card according to the present invention is an optical card obtained by laminating an optical recording member having at least a transparent protective layer and an optical recording material layer laminated on a card base material. In the card, a polycarbonate resin is used for the transparent protective layer, and the shrinkage rate is 12%.
A surface-cured layer having a thickness of 20 μm or more made of the following radiation-curable resin is provided on the transparent protective layer.

[0007]

The radiation curable resin having a shrinkage of 12% or less can suppress the warp of the transparent protective layer even if it is thickly coated, so that it is not affected by the underlying transparent protective layer when a pencil hardness test is performed. 20 μm required to do
The above coating is possible, and it is 20μm like this.
By coating with the above thickness, a pencil hardness of H to 2H can be obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing an embodiment of the optical card according to the present invention. As shown in the figure, in the optical card of the present embodiment, the optical recording material layer 3 is provided on the lower surface of the transparent protective layer 1 made of polycarbonate resin so as to cover the pattern layer 2 and the concave and convex grooves of the pattern layer 2. The card base material 4 has the adhesive layer 5 so that the optical recording material layer 3 is sandwiched therein.
And the surface-hardened layer 6 is further laminated on the transparent protective layer 1.

The polycarbonate resin (PC) used for the transparent protective layer 1 is preferably one having abundant optical characteristics. Specifically, the light transmittance is 90% or more (780 nm, 830 n).
m), refractive index 1.59 or less (780 nm, 830 n
m), birefringence of 100 nm or less (single pass) or optical elastic axis ± 5% or less is preferably used. The thickness is
It is preferably about 380 ± 20 μm including the surface hardened layer. Specifically, when the 2P method is used for forming the pattern layer 2, extruded "Teijin-made Panlite film", "GE-made, Lexan film" or the like can be used.

The surface hardened layer 6 is formed to a thickness of 20 μm or more using a radiation curable resin containing a functional monomer and / or a functional oligomer and having a shrinkage ratio of 12% or less. For example, when a radiation curable resin having a shrinkage ratio of 12.3% is formed on a PC sheet of 200 × 200 mm and a thickness of 0.4 μm with a thickness of 20 μm and placed on a desk, the warp of the PC sheet is 4.5 mm. However, when a single-wafer process is used, a warp of 4 mm or more as described above is not preferable because it interferes with a subsequent process. Further, when the card is formed into a card form, the warp of the card inherits the warp of the PC sheet and becomes 2.2 mm, which is out of the specification as a card, and further the optical characteristics are deteriorated. Similarly, when a radiation curable resin having a shrinkage of 11.9% is formed to a thickness of 20 μm and placed on a desk, the warp of the PC sheet is 4.0 mm, and the warp when the optical card is 1.8 mm. It is within specifications. Therefore, in the present invention, a radiation curable resin having a shrinkage ratio of 12% or less is used.

As the functional monomer, monofunctional acrylates (2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, etc.), bifunctional acrylates (1,3-butanediol diacrylate, 1,4-butane) are used. Diol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, etc.), trifunctional acrylate (pentaerythritol triacrylate, trimethylolpropane triacrylate, etc.), tetrafunctional acrylate (pentaerythritol tetraacrylate) Etc.) 5-functional acrylates (dipentaerythritol pentaacrylate, etc.), 6-functional acrylates (dipentaerythritol hexaacryl) Etc.), 5 as such multifunctional acrylates or more functional acrylate (dipentaerythritol penta and hexaacrylate, etc.) can be used.

As the functional oligomer, epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, silicone acrylate, unsaturated polyester, polyene / thiol and the like can be used.

N-vinylpyrrolidone as a polycarbonate adhesion-imparting agent and reaction diluent, and an initiator (benzoin-based, acetophenone-based, thioxanthone-based, peroxide-based, etc.) Irgacure is added to the above-mentioned functional monomer and / or functional oligomer. By combining 651, 184 and the like, a radiation curable resin is produced so that the shrinkage rate is 12% or less. Depending on the case, a photoinitiator aid (amine-based, quinone-based, etc.), a thermal polymerization inhibitor, a filler (inorganic or organic), a thixotropic agent, a plasticizer, a non-reactive polymer, a colorant and the like may be added. Generally, when a polyfunctional acrylate is used, it tends to be hard, but the shrinkage ratio tends to increase. Since a surface-hardened layer having a thickness of 20 μm or more is provided so as not to be influenced by the base, a shrinkage rate of up to 12% is an allowable range in order to reduce warpage and maintain hardness. In order to satisfy the warp and hardness, the shrinkage rate is 10% and the thickness is 25 to 3
0 μm is most suitable.

The surface-cured layer 6 may be mixed with 0.01 to 10 parts by weight of an internally curable silicone, silicone or the like as a leveling agent with respect to 100 parts by weight of the functional monomer or functional oligomer. When the leveling agent is mixed in an amount exceeding 10 parts by weight, the adhesion to the transparent protective layer 1 becomes poor. Further, an antistatic agent may be added to the surface hardened layer 6 in order to prevent electrification.

The surface hardened layer 6 is applied by a gravure coating method, a roll coating method, a comma coating method, a spin coating method, a knife coating method, a silk screen method, a T-die coating method, a slide coating method, a slit reverse method or the like. . in this case,
The coating may be performed by appropriately diluting with a solvent. The surface hardened layer 6 may be overprinted to form a multi-layered state. In this case, a leveling agent and / or an antistatic agent may be mixed with the uppermost radiation curable resin.

The pattern layer 2 formed on the lower surface of the transparent protective layer 1 is formed as a pattern layer by the generally known 2P method, injection method, casting method or the like.
At this time, when the pattern layer is formed by the 2P method, a UV-curable resin is used, and by the injection method or the casting method, the same transparent protective layer is used.

As the optical recording material layer 3, in addition to the commonly used metal-based optical recording materials such as tellurium-based and bismuth-based materials, dye-based optical recording materials such as phthalocyanine-based materials and naphthoquinone-based materials can be used. Further, not only the write-once type but also the ROM type may be used.

As the card substrate 4, polyvinyl chloride,
Polyethylene terephthalate, AS, polycarbonate, polypropylene and the like can be used. When polyvinyl chloride is used, the composition is 0.05 / 0.
20 / 0.05mm, 0.05 / 0.24 / 0.05m
m, 0.05 / 0.26 / 0.05 mm, 0.05 /
3 layers of 0.30 / 0.05mm, 0.20 / 0.10
mm, 0.24 / 0.10 mm, 0.26 / 0.10 m
m, two layers of 0.30 / 0.10 mm, 0.30 mm,
Any layer structure is possible, such as one layer of 0.34 mm, 0.36 mm, and 0.40 mm. In addition, 0.10m
m and 0.05 mm are transparent polyvinyl chloride,
Those with 0.20 mm or more are opalescent polyvinyl chloride.
Then, in order to increase the abrasion resistance of printing, printing is performed on opal white polyvinyl chloride, and heat fusion is performed with transparent polyvinyl chloride. 2
Layers or three layers are preferred.

As the adhesive used for the adhesive layer 5, conventionally known ones such as urethane type, epoxy type, acrylic type, vinyl type and amide type can be used. However, since the adhesive is in direct contact with the optical recording material layer, It is preferable that the recording sensitivity is good and the temperature and humidity are excellent. The film thickness is preferably about 10 to 100 μm, and is applied by a gravure coating method, a spin coating method, a knife coating method, a silk screen method, a Miyabar coating method, a T-die coating method, etc., and a flat press method, a roll press method, etc. Heat press to bond.

When the recording sensitivity of the optical recording material layer is low, a sensitizing layer is formed between the optical recording material layer and the adhesive layer, but this is not necessary if the recording sensitivity is sufficient. Further, the adhesive layer is in contact with the optical recording material layer, but if the adhesive deteriorates the sensitivity of the optical recording material layer, a transparent protective layer is provided to avoid this. When the sensitizing layer is provided, the transparent protective layer is formed between the transparent protective layer and the adhesive layer, but it can also serve as the sensitizing layer. However, when a material that does not deteriorate the optical recording material layer is selected, it is not necessary to provide this transparent protective layer.

In order to diversify the use of the card, a magnetic stripe may be provided on the same surface as the optical recording member or on the opposite surface or both surfaces of the card substrate, or an IC may be provided on the same surface as the optical recording member or on the opposite surface. A module should be provided.

Next, a specific example will be described together with a comparative example.

(Specific Example 1) 200 × 2 with a thickness of 0.4 mm
Extrusion-molded polycarbonate of 00 mm size was used as a transparent protective layer, and a radiation curable resin having the following composition was applied on one side of the transparent protective layer with a miya bar to a thickness of 30 mm, and then UV lamp (made by Fusion, microwave method) ) Was irradiated and hardened to form a surface-hardened layer. The shrinkage ratio of this radiation-curable resin during UV curing was 9.6%, and the warp at the time when the surface-cured layer was formed on the transparent protective layer was 2.5 mm. Further, Taber abrasion was CS-10, 1 kg load, 100 rotations, haze value was 15.0%, and pencil hardness was H. Urethane acrylate oligomer (Nippon Gosei Kagaku Kogyo, Gocerac UV7500B) 100 parts by weight Hexamethylene diacrylate (Nippon Kayaku, Kayarad HDDA) 3 parts by weight Pentaerythritol triacrylate (Toagosei Kagaku, Aronix M-305) 3 parts by weight Dipentaerythritol hexaacrylate (Nippon Kayaku, Kayarad DPHA) 3 parts by weight N-vinylpyrrolidone (Toagosei Kagaku, Aronix M-150) 50 parts by weight 1-hydroxycyclohexyl phenyl ketone (Ciba Geigy, Irgacure 184) 10 Parts by weight

Next, a guide track pattern layer was formed by the 2P method on the opposite surface of the transparent protective layer having the surface hardened layer, and TeOx was sputtered on the guide track pattern layer to form an optical recording material layer. On the other hand, double-sided silk offset printing is performed on a 0.20 mm opalescent vinyl core sheet,
It was sandwiched between two 0.05 mm oversheets and heat-bonded to prepare a three-layer card base material. A magnetic tape of 650 Oersted was formed on one surface of the oversheet. Then, the card base material and the transparent protective layer were adhered to each other using an adhesive (manufactured by Toray, TU-4210). After the adhesive was cured, it was punched out into a card size (85.5 × 54 mm) to produce an optical card.

In contrast to the optical card obtained as described above, an optical card R / W (manufactured by OMRON, 3B3H-DJ-0
When data of 100 tracks was written and read in 1), the error rate was 1 × 10 ⁻⁴ or less, which was good. Further, there were no problems in bending strength, adhesiveness, permeability, and warpage, and the temperature and humidity storability was good, and the card was sufficiently durable to use.

(Specific Example 2) The same extruded polycarbonate as in Specific Example 1 was used as a transparent protective layer, and a radiation curable resin having the following composition was applied to one side of the transparent protective layer with a bar to a thickness of 20 mm. A UV lamp (manufactured by Fusion, microwave system) was irradiated to the above to cure and form a surface-hardened layer. The shrinkage factor of this radiation-curable resin during UV curing was 11.9%, and the warp at the time when the surface-cured layer was formed on the transparent protective layer was 4.0 mm. The Taber abrasion was CS-10, 1 kg load, 100 rotations, haze value was 15.8%, and pencil hardness was H. Urethane acrylate oligomer (Nippon Gosei Kagaku Kogyo, Gocelac UV7500B) 100 parts by weight pentaerythritol triacrylate (Toagosei Kagaku, Aronix M-305) 10 parts by weight pentaerythritol tetraacrylate (Toagosei Kagaku, Aronix M-450) 10 Parts by weight dipentaerythritol hexaacrylate (Nippon Kayaku, Kayarad DPHA) 3 parts by weight N-vinylpyrrolidone (Toagosei Kagaku, Aronix M-150) 50 parts by weight 1-hydroxycyclohexyl phenyl ketone (Ciba Geigy, Irgacure 184) ) 10 parts by weight Reactive Silicone (X-22-5002, manufactured by Shin-Etsu Silicone) 1 part by weight

Thereafter, in the same manner as in Example 1, a pattern layer,
An optical recording material layer was formed, bonded to a card base material, and then punched into a card size to prepare an optical card. Then, an optical card R / W (manufactured by OMRON, 3B3H-DJ-01) was used for 100
When the data of the track was written and read, the error rate was 1 × 10 ⁻⁴ or less, which was good. Also,
There were no problems with respect to bending strength, adhesion, permeability, and warpage, and the temperature and humidity storage properties were good, and the card was sufficiently durable to use.

(Comparative Example 1) 200 × 2 with a thickness of 0.4 mm
Extrusion-molded polycarbonate of 00 mm size was used as a transparent protective layer, and a radiation curable resin having the following composition was applied on one side thereof with a miya bar to a thickness of 10 μm, and a UV lamp (made by Fusion, microwave method)
Was irradiated and cured to form a surface-cured layer. The shrinkage factor of this radiation-curable resin during UV curing is 1
It was 3.5%. Dipentaerythritol hexaacrylate (Nippon Kayaku, Kayarad DPHA) 10 parts by weight Pentaerythritol tetraacrylate (Toa Gosei Kagaku, Aronix M-450) 10 parts by weight Urethane acrylate oligomer (Nippon Gosei Chemical UV7500B) 2 parts by weight Parts N-vinylpyrrolidone (Toagosei Kagaku, Aronix M-150) 5 parts by weight 1-hydroxycyclohexyl phenyl ketone (Ciba-Geigy, Irgacure 184) 0.5 parts by weight

When only the surface-hardened layer was formed to a thickness of 10 μm in this manner, Taber abrasion was CS-10, 1k.
The haze value was 9.5% at g load and 100 rotations, but the pencil hardness was HB. The warpage was 3.5 mm. If the thickness is insufficient as described above, sufficient pencil hardness cannot be obtained.

Comparative Example 2 In Comparative Example 1, when the surface effect layer was formed to a thickness of 25 μm, the Taber abrasion had a haze value of 9.5% and the pencil hardness was H. However, the warp at this time was 4.8 mm, and cracks were generated in the bending test. As described above, when a material having a large shrinkage ratio is used, the warp becomes large as the thickness becomes large, resulting in inferior bending properness.

[0032]

As described above, in the optical card of the present invention, a polycarbonate resin is used for the transparent protective layer, and a thickness of 20 μm or more made of a radiation curable resin having a shrinkage rate of 12% or less is formed on the transparent protective layer. Since it has a surface-hardened layer, it is low in price and excellent in bendability, but while using polycarbonate with a low pencil hardness for the transparent protective layer, it makes use of its characteristic of less warp and also has scratch resistance. An excellent optical card can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a general optical card.

FIG. 2 is a sectional view showing an embodiment of an optical card according to the present invention.

[Explanation of symbols]

 1 Transparent Protective Layer 2 Pattern Layer 3 Optical Recording Material Layer 4 Card Base Material 5 Adhesive Layer 6 Surface Hardening Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G06K 19/08

Claims (8)

[Claims] 1. An optical card in which an optical recording member having at least a transparent protective layer and an optical recording material layer laminated together is laminated on a card substrate, and a polycarbonate resin is used for the transparent protective layer, and a shrinkage rate is 12%. An optical card, characterized in that a surface-cured layer having a thickness of 20 μm or more made of the following radiation-curable resin is provided on the transparent protective layer. 2. The optical card according to claim 1, wherein a leveling agent is mixed with the radiation curable resin. 3. The optical card according to claim 1, wherein the radiation curable resin is mixed with an antistatic agent. 4. The optical card according to claim 1, wherein an IC module and / or a magnetic stripe is provided on a part of the card base material. 5. The optical card according to claim 1, wherein the surface-hardened layer is formed in multiple layers. 6. The optical card according to claim 5, wherein a leveling agent is mixed with the uppermost radiation-curable resin in the surface-cured layers formed in multiple layers. 7. The optical card according to claim 5, wherein an antistatic agent is mixed with the uppermost radiation curable resin in the surface-cured layers formed in multiple layers. 8. The optical card according to claim 4, 5, 6 or 7, wherein an IC module and / or a magnetic stripe is provided on a part of the card base material.