JPH02239438A - Optical card - Google Patents

Abstract

PURPOSE:To improve flexibility and scratching resistance by providing a hard coat layer comprising two or more layers of radiation-curing type resin each of which contains two or more acryloil groups on a transparent substrate layer. CONSTITUTION:The hard coat layer 5 comprising two or more layers 51, 52 of radiation-curing type resin each of which contains two or more acryloil groups in formed on a transparent substrate layer 1. The radiation-curing resin is such as UV-curing resin or electron beam curing resin, and comprises at least mixtures of oligoester acrylate and urethane acrylate. The outer layer of the radiation-curing resin layers is made the harder. Thereby, the obtd. optical card has high scratching resistance and flexibility without influence on reading or writing of informations.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a read-only, additionally writable, and record-erasable optical card. Conventional technology> Conventionally, a thin film made of a low-melting point metal or organic dye is provided as a recording layer on the base layer, data is recorded on the thin film using laser light, etc., and the recorded data is optically reproduced. Optical recording media are known, especially card-shaped optical recording media (hereinafter referred to as optical cards) because of their large recording capacity! ■It is considered to be the most effective recording medium compared to cards that use IC. However, since recording and reproduction are performed optically, it is important to maintain stable irradiation accuracy, and it is also necessary to prevent errors when writing and reading information. The optical card (C) has an optical recording section (6) on the card surface as shown in FIG. 3, and the basic structure of a conventional optical card is as shown in FIG. Characteristically, it consists of at least the following three layers. In the figure (11 is a transparent base material layer that serves as both a surface layer and a support), which has high transmittance in the wavelength range of the light source used for recording and reproduction, and which does not cause deformation or deterioration in the subsequent process. There is no particular limitation as long as it satisfies mechanical strength and optical properties, and acids include polycarbonate resins, acrylic resins, urethane resins, epoxy resins, polyvinyl chloride resins, polyolefin resins, and styrene polycarbonate blends. In the figure, (2) is an optical recording layer provided on the transparent base material layer, and for example, in a direct read after write (DI?AW) type, tellurium, bismuth,
Inorganic materials made of low melting point metals such as aluminum and their alloys, or anthraquinone-based, naphthoquinone-based, triphenylmethane-based, carbocyanine-based, merocyanine-based, xanthene-based, azo-based, azine-based, thiazine-based, oxazine-based, lid opening It is generally formed from organic dyes containing organic dyes such as cyanine, and is erasable and writable (EDRAM).
) type is TbFe-GdTbFe, GdTbFe,
It is formed of a magneto-optical type such as TbFe type and a phase change type, and if it is a read-only type (ROM> type, it is formed with information recorded in advance using a highly reflective metal such as aluminum. Furthermore, an adhesive layer (3) is formed. The transparent base material (1) and the optical recording layer (
There is a backing substrate (4) that supports 2). This backing substrate serves both as a protector and a support for the optical recording layer.
Generally, the same materials as the transparent base layer, such as polycarbonate resin, acrylic resin, urethane resin, epoxy resin, polyvinyl chloride resin, polyolefin resin, and styrene polycarbonate blend resin, are used. In this line, an optical card generally has a structure in which an optical recording material is sandwiched between a transparent substrate as a support and a backing substrate as a transparent or opaque substrate. The recording/reproducing method for this optical card is to record information by irradiating the optical recording layer with a laser beam such as a semiconductor laser through a transparent substrate and forming holes or pits by the heat of the laser beam. Using the same laser light source as during recording, I/! In this method, the recording layer is irradiated with a weak irradiation light amount to about 0, and information is read by detecting changes in reflectance. <Invention tries to solve! II! > However, the scratch resistance of the transparent base material laminated on the recording layer has a large effect on the reliability of writing and reading information on the optical card. In other words, transparent substrates made of conventionally used polycarbonate resins, acrylic resins, urethane resins, epoxy resins, polyvinyl chloride resins, polyolefin resins, styrene polycarbonate blend resins, etc. have insufficient scratch resistance regardless of the degree of scratch resistance. , one of the causes of errors in writing and reading information, is the fact that optical cards are carried around and used for long periods of time, which can cause scratches on the recording surface, and dirt can also adhere to these scratches. For this reason, there remains a problem with reliability when it is put into practical use as an optical card. Therefore, the present invention has been made to solve the above-mentioned problems, and its object is to provide a protective layer for an optical card that improves the scratch resistance of the recording surface and has extremely excellent mechanical strength and optical properties. ．． <Means for Solving the Problems> In an optical card in which an optical recording layer and a transparent base material layer are sequentially laminated on a card base material (backing substrate), at least two acryloyl groups are provided on each of the transparent base materials. This is an optical card provided with a hard coat layer formed by laminating two or more layers of radiation curable resin having the above, and the radiation curable resin is an ultraviolet ray curable resin or an electron beam curable resin, and at least oligoester acrylate and Consisting of a mixed system of urethane acrylate, and II! This is an optical card with a radiation-curable resin layer whose hardness increases toward the outermost layer. <Function> According to the present invention, two or more layers of radiation-curable resin each having at least two acryloyl groups are formed on the surface opposite to the surface on which the optical recording portion is formed of the transparent substrate, and the hardness of the resin increases toward the outermost layer. This hard coat layer suppresses the occurrence of scratches even when the optical card is carried and used for long periods of time, does not affect the writing and reading of information, and can sufficiently follow the flexibility of the optical card. is formed, thus providing an optical card with high scratch resistance and flexibility. Embodiments Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings. FIG. 1 is a partially enlarged cross-sectional view of an optical card according to the present invention, in which an optical recording layer (2) is provided on at least a part of a transparent base material shown as (1) in the figure, and is backed with an adhesive layer (3). Substrate (4
) and at least two or more hard code layers (5) on the surface opposite to the laminated surface of the optical recording N (2) of the transparent substrate (+).
This is an optical card made by laminating multiple layers. The hard coat layer (5) in the present invention is a laminated layer of two or more radiation-curable resins each having two or more acryloyl groups, and the radiation-curable resin is an ultraviolet-curable resin or an electron beam-curable resin. If two or more layers are laminated, the hardness increases toward the outermost layer. Radiation-curable resins include urethane acrylate resins having at least two or more acryloyl groups, epoxy acrylate resins, acrylate resins, oligoesters, acrylate resins, etc., and preferably those consisting of a mixed system of urethane acrylate resins and oligoester acrylate resins. The urethane acrylate resin component often imparts flexibility to the card, and the oligoester acrylate resin component imparts hardness. Furthermore, by laminating layers of hardness from low to high on the transparent base material side, it is possible to maintain the flexibility of the card as well as the role of a surface protective layer. A specific example will be described below.

ll1 Two soil ■ Thickness 0.4 s/m, 100 ■ / hanging x 80 m / - size melt extrusion molded polycarbonate base Temporarily coated with UV curable resin, groove pitch 12 μm, groove width 2.5 μm
0.3m thick molded guide groove with depth 0.2ttm
A transparent substrate (1) with guide grooves formed was prepared by pressing a 7 m long nickel standby plate against the polycarbonate substrate and irradiating it with ultraviolet rays to harden the resin. 300 Te in the guide groove of the transparent base material (1) obtained in ■■
The optical recording layer (2) was formed by vapor deposition using a resistance heating method to a thickness of about 100 yen. ■ On this optical recording layer (2), adhere a hard white PVC (4) of IQOmls x Floats size with a thickness of 0.3 a/m via an epoxy adhesive (3) (manufactured by Ciba Geigy, Alladite). , card size 85 after curing
．． A punched optical card was obtained at 5m/■ x 54m/1. ■Next, on the polycarbonate surface of the optical card obtained in step (■), a coating agent consisting of the following composition (a) is applied using a spin coater so that the film thickness after drying and curing is 2 to 3 microns. The first hard coat (51) was obtained. Composition (a) Urethane acrylate (manufactured by Negami Kogyo Shisha Co., Ltd.: Art Resin ON-730} 1c) 50 parts Oligoester acrylate (manufactured by Toagosei ■ Co., Ltd.: Aguchi Nix M-6100) 50 parts total 100 parts Obtained from On top of the first hard coat (5?), a coating agent consisting of the following composition (t)) was further applied using a spin coater so that the film thickness after drying and curing was 2 to 3 microns. Second hard call} (52) was obtained. Composition Φ》 Urethane acrylate (manufactured by Negami Kogyo: Art Register: /
ON-730IC) 50 parts oligoester acrylate (manufactured by Toagosei: Aronix M-8030
) Total of 50 parts 100 parts■Then, the first hard coat layer (51) and second hard coat layer (52) obtained as in ■■ were subjected to electron beam irradiation equipment (manufactured by Nissin High Voltage Co., Ltd.: Absorbed dose 3. An optical card was obtained by curing under OMrad conditions. ■The optical card obtained in the above manner is heated using a semiconductor laser (
8aL IOOKHZ), a good recording was made, and further processing with a 0.6mW semiconductor laser gave a good signal, and the mechanical strength such as impact resistance and bending resistance was sufficient for card use. It was bearable. 1" 1 Group 22F ■ Coating consisting of the following composition (C) on one side of 1 sheet of {melt extrusion molded polycarbonate} of 100-/a x 80-/- size with a thickness of 0.4 m/1. The agent was applied with a spray gun so that the film thickness after drying and curing was 2 to 3 microns to obtain a first hard coat layer (51). Composition (C)
Urethane acrylate (manufactured by II Kamikogyo Co., Ltd.: Art Resin ON-7301IC) 50 parts Oligoester acrylate (manufactured by Toagosei Co., Ltd.: Aronix?I-
6100) 50 parts total 100 parts On top of the first hard coat layer (51) obtained in ■■, a coating agent consisting of the following composition (d) was applied with a spray gun,
A second hard coat (52) was obtained by coating so that the film thickness after drying and curing was 2 to 3 microns. Composition (d) Urethane acrylate (manufactured by Negami Kogyo Co., Ltd. = 7 − }
Recipe: /UN-730}IC) 30 parts oligoester acrylate (manufactured by Nippon Kayaku Corporation: KAYARAD
MAND) 70 copies total 100 copies ■Then, the first hard coat layer (51) and second hard coat li (52) obtained as in ■■ were heated using an electron beam irradiation device (Nissin High Voltage ■: manufactured by Nissin High Voltage ■). Curetron) at an absorbed dose of 3.0 Mrad. ■Next, an ultraviolet curable resin is applied to the uncoated surface of the polycarbonate substrate containing the first hard coat layer (51) and the second hard coat layer (52), and a groove bit 12 t is applied.
A 0.31/1 thick nickel stand board with a guide groove of 2.5 μm in groove width and 0.2 μm in depth was pressed against it, and ultraviolet rays were irradiated from the polycarbonate substrate side to remove the resin. Guide grooves were formed in the transparent base Fi(1) by curing. (2) Next, Te was deposited to a thickness of 300 nm on the guide surface of the transparent substrate (1) obtained in (2) by resistance heating to form an optical recording layer (2). ■ On this optical recording layer (2), an epoxy adhesive (3) (manufactured by Ciba Geigy, Araldite) is applied at 0.3 s/s.
Glue hard white PVC (4) with a thickness of 100m/s
I got a punched optical card for g/gull x 54 1/-. ■The optical card obtained in the above manner is heated using a semiconductor laser (
8a1 10k It was sufficiently durable. Next, a comparative example will be described to confirm the effectiveness of the present invention,
explain. ■ A coating agent of the composition (aluminum) also described in Example-1 (■) was applied on the surface of the polycarbonate substrate of an optical card obtained by the method described in ■■■ of Example-1. A hard coat layer was applied using a spin coater so that the film thickness after drying and curing was 10 microns. On the polycarbonate x mask of the optical card obtained by the method, a coating agent consisting of the composition (d) described in Example 2 (■) was applied using a spin coater until the film thickness after drying and curing was about 10 microns. The optical cards obtained in Example-1, Example-2, Comparative Example-1, and Comparative Example-2 were recorded with a semiconductor laser (8 mW, 'IOKHZ). After that, each hard coat surface was rubbed once with a 11500 Gio file using a Gakushin-type dyed abrasion fastness tester (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.) under a load of lOOg. After that, the error rate of each optical card was measured using a 0.6-digit semiconductor laser, and the results are shown in Table 1. Table 1 As described above, the present invention has excellent flexibility and scratch resistance. It has become clear that an optical card can be obtained. Effects> As described above, in the optical card according to the present invention, the hard coat layer as a protective layer makes the optical card portable and long-lasting without reducing the recording sensitivity. It suppresses the occurrence of scratches even when used for a period of time, and can sufficiently follow the disposable properties of optical cards, making it possible to provide stable and high reliability.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view of an optical card of the present invention, FIG. 2 is a partially enlarged sectional view of a conventional optical card, and FIG. 3 is a front view of a general optical card. (11 3! i Bright base material (2) Optical recording layer (3) Adhesive layer (4) Backing substrate (5) Hard coat layer (6) Optical recording section (5l) First hard coat layer (52) Second hard coat Layer (Cl) Optical card patent application Representative Kazuo Suzuki, Toppan Printing Co., Ltd.

Claims (3)

[Claims] (1) In an optical card in which an optical recording layer and a transparent base material layer are sequentially laminated on a card base material, a radiation curable resin each having at least two or more acryloyl groups is provided on the transparent base material layer. An optical card characterized by having a hard coat layer formed by laminating two or more layers. (2) The optical card according to claim 1, wherein the radiation curable resin is an ultraviolet curable resin or an electron beam curable resin, and is composed of a mixed system of at least oligoester acrylate and urethane acrylate. (3) In the optical card having a hard coat layer formed by laminating two or more layers of the radiation curable resin, the hardness of the laminated radiation curable resin is increased toward the outermost layer. light card.