JPH0524386A - Optical card - Google Patents

Abstract

PURPOSE:To obtain an optical card not deteriorated by UV rays. CONSTITUTION:A transparent protecting layer 5 for protecting an optical recording layer 4 recording data is covered with a UV absorbing layer 7. Therefore, the UV rays are absorbed by the UV absorbing layer 7 and the transparent protecting layer 5 comes not to absorb the UV rays, thus causing no deterioration of the transparent protecting layer 5.

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 as a cash card, a credit card, an ID card or the like.

[0002]

2. Description of the Related Art Optical cards are large-capacity recording media characterized by portability and flexibility, and have recently been expected to be used in cash cards, credit cards, and ID cards. However, since it is in the form of a card, it is exposed to a severe environment incomparable to a floppy disk or the like in which a recording medium is stored in a cartridge.

For this reason, what protects an optical recording layer with a transparent protective layer is disclosed in Japanese Patent Application Laid-Open No. 62-289938. As shown in FIG. 3, an optical recording layer 4 composed of a metal thin film layer for recording an optical information pattern 3 is formed on a card substrate 1 via an adhesive layer 2 and the optical recording layer 4 is protected by the optical recording layer 4. The transparent protective layer 5 is laminated. Then, a cured resin layer 6 having antistatic treatment applied to the front surface and the back surface is provided.

The formation of the above-mentioned information pattern 3 is carried out by etching the photoresist layer at once, or writing is carried out by a laser beam one by one. The transparent protective layer 5 is a material that retains the portability and flexibility of the optical card and needs to be optically transparent. Therefore, for example, a polycarbonate (PC) resin, a polymethylmethacrylate (PMM) is used.
A) A transparent plastic material such as resin is selected.

[0005]

However, since these resins absorb ultraviolet rays, destruction of molecular bonds progresses over time, white turbidity, cracks, etc. occur, and information pattern reproduction errors occur, and There was a problem that the card itself would be mechanically damaged.

The present invention has been made in view of such circumstances, and an object thereof is to obtain an optical card which is not deteriorated by ultraviolet rays.

[0007]

In order to solve such problems, the present invention provides an optical card having a transparent protective layer for protecting an optical recording layer on which information is recorded, in which at least the transparent protective layer is an ultraviolet absorbing layer. It is characterized by being covered.

[0008]

Since the ultraviolet absorbing layer absorbs the ultraviolet rays, the transparent protective layer does not absorb the ultraviolet rays, and therefore the transparent protective layer does not deteriorate.

[0009]

EXAMPLE FIG. 1 is a diagram showing an example of an optical card to which the present invention is applied, in which an epoxy or acrylic adhesive layer is formed on a card substrate 1 made of polyvinyl chloride resin as a backing layer. An optical recording layer 4 on which an information pattern 3 is recorded is provided via 2.

The optical recording layer 4 is made of a metal having excellent light reflectivity.
For example, Al, Ni, Cr, Au, Pt, etc., and alloys mainly of these, or Te, S which are low melting point metals.
e, Bi, Sn, Pb and alloys containing these as the main components, such as Te-Se, Te-Se-Sb, etc., or organic dye materials, etc. are used, and they are deposited by means of vapor deposition, sputtering, spin coating, etc. It is formed.
In addition, magneto-optical recording materials such as TbFeCo and DyFeC
o, NdFeCo, NdDyFeCo, etc. can also be used.

The transparent protective layer 5 protects the optical recording layer 4 of the optical card, and the characteristics required for the transparent protective layer 5 are high light transmittance, smoothness, and uniform thickness. It has uniform optical properties, is hard, and is flexible. For this purpose, for example, polycarbonate resin, polyethylene terephthalate resin, polymethylmethacrylate resin can be used.

The surface hardness of these resin materials is about B to HB in pencil hardness, and the surface is scratched in a normal use environment. Further, as described above, since it has the property of absorbing ultraviolet rays and becoming brittle, in the present invention, the ultraviolet absorbing layer 7 formed of, for example, an ultraviolet curable resin (LE-3629 manufactured by Toyo Ink) is 1000 to 10000.
It is protected by covering it in the Angstrom range.

As shown in FIG. 2, the absorbance characteristic of the ultraviolet absorbing layer 7 is such that the transmittance is 4 in the ultraviolet region having a wavelength of 350 nm or less.
It has characteristics of 0% or less. The ultraviolet absorbing effect of the film-like ultraviolet absorbing layer 7 can prevent the transparent protective layer 5 thereunder from being deteriorated by ultraviolet rays. The ultraviolet absorbing layer 7
The transparent protective layer 5 can be peeled off if necessary, and coated or reattached again, and the transparent protective layer 5 can be always protected from ultraviolet rays. Also, the pencil hardness used in this example is 7H, which is sufficiently hard as compared with the transparent protective layer 5 and can prevent the optical card from being scratched or the like when used and carried.

Further, an antistatic effect on the surface of the optical card can be obtained by blending a surfactant selected from cationic, anionic and amphoteric agents with an ultraviolet curable resin as an antistatic treating agent. Surfactants consisting of cationic, especially quaternary ammonium salts are preferred.
Further, the surfactant may be blended with the ultraviolet absorbing layer 5, or a thin film layer may be formed on the surface.

Since the card base material 1 as the backing layer is often colored or printed, a white one is most suitable, but of course other synthetic resins can be used without any problem.

[0016]

As described above, according to the optical card of the present invention, since at least the transparent protective layer is covered with the ultraviolet absorbing layer, the transparent protective layer is prevented from being deteriorated by ultraviolet rays, and the durability is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of an optical card configured by applying the present invention.

FIG. 2 is a graph showing wavelength characteristics of an ultraviolet absorbing layer.

FIG. 3 is a sectional view showing an example of a conventional optical card.

[Explanation of symbols]

 1 Card Base Material 2 Adhesive Layer 3 Information Pattern 4 Optical Recording Layer 5 Transparent Protective Layer 6 Cured Resin Layer 7 Ultraviolet Absorption Layer

Claims (1)

Claim: What is claimed is: 1. An optical card having a transparent protective layer for protecting an optical recording layer on which information is recorded, wherein at least the transparent protective layer is covered with an ultraviolet absorbing layer.