JP2001176135A - Optical card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical card which lessens the limitation on the color tones of printing layers visually observed through an optical recording layer and has an excellent design characteristic and visibility. SOLUTION: The optical card 10 has a card substrate 1, the optical recording layer 3 laminated via an adhesive layer 2 on the card substrate 1 and a transparent protective layer 4 laminated on the card substrate 1 so as to cover the optical recording layer 3. A card substrate of a three-layered structure laminated with an over-sheet 1a, a core sheet 1b and an over-sheet 1c is used for the card substrate 1. The card substrate 1 is provided with the printing layers (visible information layers) 8a and 8b in regions overlapping on the optical recording layer 3. The optical recording layer 3 contains tellurium oxide (TeOx) and the degree of oxidation X thereof ranges from 1.3 to 1.7. The thickness of the optical recording layer 3 ranges from 300 to 800 angstrom. The transparent protective layer 4 has a light transparent base material 5, a transparent substrate 6 laminated on the light transparent base material 5 and a hard- coating layer 7 laminated on the transparent substrate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical card for optically recording information, and more particularly to an optical card in which a visible information layer provided on a card substrate can be viewed through the optical recording layer.

[0002]

2. Description of the Related Art Hitherto, as an optical recording medium for optically recording information, an optical card having a card substrate and an optical recording layer laminated on the card substrate has been known. Generally, in such an optical card, the optical recording layer occupies most of the card substrate, which affects the design selectivity of the entire optical card.

[0003] For this reason, conventionally, a printed layer formed of a pattern, a character, and the like provided on a card substrate is made visible through a transparent optical recording layer, thereby improving the design selectivity of the entire optical card. Attempts have been made.

Specifically, for example, an optical card (see Japanese Patent No. 2754215) in which a logo or the like printed on a card substrate is made visible through a transparent optical recording layer made of a polymethine-based organic material or the like, , Tellurium oxide (T
There has been proposed an optical card (see Japanese Patent Application Laid-Open No. 6-55886) in which characters, patterns, and the like printed on a card substrate can be viewed through a transparent optical recording layer made of eOx).

[0005]

However, among the conventional optical cards described above, the optical card described in Japanese Patent No. 2754215 uses a polymethine-based organic material for the optical recording layer. The recording layer itself has a blue color, and there is a problem that when the printing layer provided on the card substrate is visually observed through such an optical recording layer, the printing layer is not expressed in the original color tone. Specifically, since the optical recording layer has a blue color, the blue color tone is emphasized and the expression of the red color tone is restricted. In addition, because of the visibility when viewed through the blue optical recording layer, the expression of a logo or the like is limited (the logo or the like is expressed in white on a dark background such as black), and the overall It becomes a dark image.

On the other hand, in the optical card described in JP-A-6-55886, the transparency of the optical recording layer is low. In addition, there is a problem that the color tone of the print layer viewed through the optical recording layer is significantly different from the color tone of the actual print layer.

The present invention has been made in view of the above points, and provides an optical card having excellent design and visibility by reducing the restriction on the color tone of the print layer viewed through the optical recording layer. The purpose is to:

[0008]

According to the present invention, there is provided a card substrate, an optical recording layer provided on the card substrate, and a transparent protective layer provided on the card substrate so as to cover the optical recording layer. Wherein the card substrate has a visible information layer in a region overlapping the optical recording layer, and the optical recording layer has a degree of oxidation x of 1.3 to 1.7 in tellurium oxide (TeOx).
An optical card is provided. In the present invention, the optical recording layer has a thickness of 300 to 8
It is preferably in the range of 00 Angstroms. Preferably, the visible information layer is a printed layer on which visible information is printed.

According to the present invention, the degree of oxidation x of tellurium oxide (TeOx) constituting the optical recording layer is in the range of 1.3 to 1.7, so that the optical recording / reading characteristics can be assured while ensuring the information reading / writing characteristics. The transparency of the layer can be improved to the maximum, so that the visible information layer provided on the card substrate can be satisfactorily viewed through the optical recording layer while maintaining its color tone.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of an optical card according to the present invention. In the present embodiment, WORM (Write Once
This will be described using an example of a read many) type optical card.

FIG. 1 is a sectional view showing an optical card according to the present embodiment (a sectional view taken along line II in FIG. 2A). In the present embodiment, the optical card shown in FIG.
% Standard width optical card) as an example.
An optical card having a narrow width as shown in FIG. 2B (an optical recording layer occupies about 33% on the card substrate) or FIG.
The present invention can be similarly applied to a wide-width optical card as shown in (1) (an optical recording layer occupies about 90% on a card substrate).

As shown in FIG. 1, an optical card 10 includes a card substrate 1, an optical recording layer 3 laminated on the card substrate 1 via an adhesive layer 2, and a card substrate so as to cover the optical recording layer 3. 1 and a transparent protective layer 4 laminated on the transparent protective layer 4.

The card substrate 1 has a three-layer structure in which an oversheet 1a, a core sheet 1b, and an oversheet 1c are laminated. The card substrate 1 is provided with printing layers (visible information layers) 8a and 8b in a region overlapping with the optical recording layer 3. Specifically, a print layer 8a is provided between the oversheet 1a and the core sheet 1b, and a print layer 8b is provided between the oversheet 1c and the core sheet 1b.

The optical recording layer 3 is made of tellurium oxide (TeO
x), and the degree of oxidation x is in the range of 1.3 to 1.7. The oxidation degree x of tellurium oxide (TeOx)
Has a predetermined relationship with the refractive index, and can be determined by measuring the refractive index of light of a predetermined wavelength with an ellipsometer. Specifically, an X-ray photoelectron spectrometer (XPS
/ ESCA) or an Auger electron spectrometer (AES) can measure the value of the degree of oxidation x.

The thickness of the optical recording layer 3 is 300 to 800.
It is preferably in the range of Angstroms. Also,
The size of the optical recording layer 3 along the substrate surface is the card substrate 1.
It is preferable that the size is such that it is not exposed from the end of the substrate.

Further, the transparent protective layer 4 comprises a light-transmitting substrate 5
And a transparent substrate 6 laminated on the light-transmitting substrate 5 and a hard coat layer 7 laminated on the transparent substrate 6. In addition, on the surface of the light transmissive substrate 5 opposite to the surface on which the transparent substrate 6 is laminated, a high reflectivity portion 5a for optical recording is provided.
An optical recording layer 3 is formed on the surface of the light-transmitting substrate 5 so as to cover the high-reflectance portion 5a and the low-reflectance portion 5b. ing.

In such an optical card 10,
Writing and reading of information to and from the optical recording layer 3 are performed by the reader / writer from the transparent protective layer 4 side as follows. That is, information is written by opening a pit (optical recording portion 9a) with a laser beam in a region of the optical recording layer 3 that overlaps with the high reflectivity portion 5a of the light transmitting base material 5. On the other hand, the information written in this way is
Reading is performed based on the contrast of the reflectance of the optical recording layer 3 between the optical recording portion 9a and the non-recording portion 9b.

Next, the optical card 1 having such a configuration will be described.
0 will be described.

(1) First, as an original plate for producing the light-transmitting substrate 5 of the transparent protective layer 4, a low-reflectance portion roughened in accordance with the shape of a guide track for information recording is provided. A roughened master is prepared.

Specifically, first, a transparent substrate (thickness 400
(μm acrylic plate) was uniformly coated with a photoresist to a thickness of 5000 angstroms by a rotary photoresist coating machine to form a photoresist layer.
Note that as the photoresist, Microposit 1400 (manufactured by Shipley Co., Ltd.) which is a positive resist (quinonediazide system) can be used.

Next, after a photomask was overlaid on the photoresist layer thus formed, the first exposure (patterning exposure) was performed with ultraviolet rays. In addition,
As the pattern of the photomask, a pattern corresponding to the shape of the guide track for information recording (width about 2.5 μm,
A linear pattern having a pitch of about 12 μm) was used.

Thereafter, exposure (roughening exposure) was performed again using a glass plate (an average roughness of 0.3 μm, # 3000 polished glass) having one surface roughened into fine irregularities.

After exposure in this manner,
By developing the photoresist layer, the photoresist in the UV-irradiated portions was removed, and the photoresist in the UV-irradiated portions was left, and the pattern of the photomask was transferred onto a transparent substrate.

(2) Next, the mother mask is duplicated by a mold press using the roughened original plate manufactured as described above.

Specifically, the step (1) is carried out on a transparent base material (acrylic plate having a thickness of 1.2 mm) via a molding agent made of an ionizing radiation-curable resin or a thermosetting resin. Were laminated and pressed by a press machine. In this state, after irradiation with ultraviolet rays, the roughened original plate and the transparent substrate were released from the mold, and a pattern was duplicated on the transparent substrate side to form a mother mask. As the molding resin, a UV curable resin (manufactured by The Inktec, SEL-
XA (mainly composed of a polyester acrylate oligomer and neopentyl glycol diacrylate monomer and added with Irgacure 184 (photopolymerization initiator)) was used.

(3) On the other hand, a hard coat layer 7 is formed on a base material to be the transparent substrate 6 of the optical card 10.

Specifically, a hard coat agent was applied by spinner coating on the base material to be the transparent substrate 6, and was irradiated with ultraviolet rays to be cured to form a hard coat layer 7.

Here, as the base material to be the transparent substrate 6,
Polycarbonate (PC) having a thickness of 400 μm was used.
In addition, polymethyl methacrylate (PMMA),
Acrylonitrile-styrene copolymer (AS resin), cellulose propionate (CP), cellulose acetate butyrate (CAB), polyvinyl chloride (PVC), polyester, and the like can also be used. Here, polycarbonate having low birefringence is used. It is preferable to use Further, as a hard coat agent to be the hard coat layer 7, an acrylic UV curable hard coat agent (UH-001, manufactured by Toray Industries, Inc.) can be used. Besides, UV curable resin (oligomer, monomer initiator)
Alternatively, a thermosetting resin such as a melamine resin can be used.

(4) Next, using the mother mask prepared in the above step (2) as a duplication master for mass duplication, the back side of the transparent substrate 6 (opposite to the hard coat layer 7) by a mold press. The light transmissive substrate 5 is formed on the (surface side).

More specifically, a duplicating resin was sandwiched between the back surface of the transparent substrate 6 and the pattern surface of the mother mask, and pressed by a press. In this state, after irradiating ultraviolet rays, the transparent substrate 6 and the mother mask are released, and the transparent substrate 6 is released.
The pattern was duplicated on the side to form a light-transmitting substrate 5. In addition, as a resin for duplication, an ultraviolet curable resin (SS-120, a urethane acrylate system, manufactured by Three Bond Co., Ltd.) was used.

(5) Subsequently, one of the light-transmitting substrates 5 is formed so as to cover the high-reflectance portions 5a and the low-reflectance portions 5b of the light-transmitting substrate 5 formed in the step (4). The optical recording layer 3 is laminated on the part.

More specifically, tellurium oxide (TeOx) is converted to 300,500,
The optical recording layer 3 was formed by vapor deposition with three different thicknesses of 800 angstroms.

(6) Aside from the series of steps (1) to (5), the card substrate 1 is manufactured.

Specifically, the card substrate 1 is provided with printed layers 8a and 8b on both sides of the core sheet 1b, and over the over-sheet layers 1a and 1b for protecting the printed layers 8a and 8b.
c.

Here, as the core sheet 1b, milky white vinyl chloride, polycarbonate, cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP), or the like can be used.
It can be about 0 to 220 μm. Further, as the oversheet layers 1a and 1c, transparent vinyl chloride, transparent CAB, transparent CAP, or the like can be used.

The printed layers 8a and 8b provided on both sides of the core sheet 1b are made of acrylic, soft vinyl chloride,
Silk ink for hard vinyl chloride etc. (for example, SS-8
Printing is performed using a series (manufactured by Toyo Ink Manufacturing Co., Ltd.) or a Sericol CAD series (manufactured by Teikoku Ink), and a desired pattern or character can be printed on the entire surface of the core sheet 1b by, for example, silk screen printing.

(7) Then, the card substrate 1 produced in the step (6) is placed on the light-transmitting substrate 5 on which the optical recording layer 3 is formed in the step (5) by an adhesive layer. Laminate through 2.

Specifically, a two-component curing type adhesive (UH-1260C, manufactured by Toray) is used as the adhesive layer 2.
At room temperature, they were adhered with a thickness of 60 μm. In this case, since the adhesive layer 2 is in direct contact with the oversheet 1a (transparent polyvinyl chloride) of the card substrate 1 over the entire surface, the adhesive layer 2 is firmly adhered.

The original plate manufactured as described above is stamped into a predetermined size on a card substrate, whereby
The optical card 10 shown in FIG.

The information writing characteristics and the visibility of the printed layers 8a and 8b were evaluated for four types of optical cards 10 manufactured by changing the material and thickness of the optical recording layer. As shown in FIG. As apparent from the following Table 1, the visibility of the print layers 8a and 8b was determined with respect to the degree of oxidation (x) of tellurium oxide forming the optical recording layer 3.
The larger the value, the better the results obtained.
The better the results were obtained, the smaller the thickness was. Here, the thickness of the optical recording layer 3 is 300 to 8 in consideration of the reading performance (recording sensitivity) of the optical card 10 and the manufacturing cost.
The thickness is preferably in the range of 00 angstrom. To ensure the visibility of the printed layers 8a and 8b within this range, the following Table 1 is used.
As can be seen from FIG. 4, it is necessary to set the lower limit of the degree of oxidation (x) to about 1.3. Regarding the information writing characteristics, the writing performance is degraded as the oxidation degree (x) of tellurium oxide is increased. Therefore, as can be seen from Table 1 below, it is necessary to set the upper limit of the degree of oxidation (x) to about 1.7 in order to ensure the information writing characteristics.

[0041]

[Table 1] As described above, according to the present embodiment, the degree of oxidation x of tellurium oxide (TeOx) forming the optical recording layer 3 is in the range of 1.3 to 1.7, so that information read / write characteristics are guaranteed. The transparency of the optical recording layer 3 can be improved to the maximum while the printing layers 8a and 8b provided on the card substrate 1 and composed of pictures, characters, and the like are kept in a state where the color tone is maintained. Can be seen easily through

More specifically, with the improvement of the transparency of the optical recording layer 3, even in the case of a pattern or character whose color tone has not been clarified conventionally, red appears to be red and yellow appears to be yellow. The color can be visually observed in a form close to the color tone. Therefore, the optical recording layer 3 of the card substrate 1
Even in the portion where is provided, it is possible to adopt a colorful design, or to change the color of items to be emphasized such as cautionary notes, thereby further improving the design. In addition, with the improvement in the transparency of the optical recording layer 3, the visibility of a picture, a character, or the like can be improved. For this reason, even in the portion of the card substrate 1 where the optical recording layer 3 is provided, it is possible to print fine characters and the like for explaining precautions and the like, and it is possible to substantially increase the printable area. it can.

In the above-described embodiment, the oversheet 1a and the core sheet 1
b, a printing layer 8a is provided between the oversheet 1c and the core sheet 1b, but the printing layer 8b is not limited to this, and the front and back sides of the core sheet 1b are opposite to the transparent protective layer 4. It is also possible to provide print layers 8a and 8b for each of the print sheets (see FIG. 3A) and to omit the oversheets 1a and 1c (see FIG. 3B).

[0044]

As described above, according to the present invention, since the degree of oxidation x of tellurium oxide (TeOx) forming the optical recording layer is in the range of 1.3 to 1.7, information reading / writing is performed. It is possible to improve the transparency of the optical recording layer to the maximum while guaranteeing the characteristics, so that the visible information layer provided on the card substrate can be visually observed through the optical recording layer while maintaining its color tone. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an optical card according to the present invention.

FIG. 2 is a plan view of the optical card shown in FIG.

FIG. 3 is a view for explaining a modification of the optical card shown in FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Card board 1a, 1c Oversheet 1b Core sheet 2 Adhesive layer 3 Optical recording layer 4 Transparent protective layer 5 Light transmissive base material 5a High reflectivity part 5b Low reflectivity part 6 Transparent substrate 7 Hard coat layer 8a, 8b Printing Layer 10 Optical Card

Claims (3)

[Claims] A card substrate, an optical recording layer provided on the card substrate, and a transparent protective layer provided on the card substrate so as to cover the optical recording layer. An optical card having a visible information layer in a region overlapping a recording layer, wherein the optical recording layer contains tellurium oxide (TeOx) having an oxidation degree x in a range of 1.3 to 1.7. 2. The optical recording layer has a thickness of 300 to 800.
2. The optical card according to claim 1, wherein the optical card is in the range of Angstroms. 3. The optical card according to claim 1, wherein the visible information layer is a printed layer on which visible information is printed.