JP2929638B2 - Optical card - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an optical card capable of optically additional writing.

[Conventional technology]

In recent years, as magnetic cards widely used in many industrial fields have been required to add more functions, optical cards have been proposed as card media having a larger recording capacity than magnetic cards, Among them, an optical card that can be additionally written has a wide range of use and is considered promising.

As an optical recording method of information on an optical card,
The direct read-after-write type (hereinafter simply referred to as DRAW type) is generally used, and so-called heat mode recording, in which the optical recording material is irradiated with a laser beam or the like to raise the temperature and cause a physical or chemical change. It is a method. Therefore
DRAW-type optical cards are characterized by the fact that the recorded information does not change and is easy to handle and store both indoors and outdoors unless exposed to a temperature change greater than the temperature rise caused by laser light irradiation. There is.

As an example of the DRAW format, a low melting point metal such as tellurium (Te), an alloy, an oxide, and a carbide thereof have been proposed, and the optical recording material held on a substrate has a change in output. A pit (hole) corresponding to the output change is formed based on the difference in surface tension between the melted laser receiving part and the surrounding unmelted part by irradiating semiconductor laser light etc. to raise the temperature and melt, and information is recorded. Is what is done. (For example, Japanese Patent Publication No. 59-35356
Reference).

As another example of the DRAW type recording material, various organic dyes are proposed, and pits are similarly formed by heating and sublimation of the optical recording material by irradiation with laser light or the like, and information is recorded. (See, for example, JP-A-58-112790).

As described above, recording materials for DRAW type optical cards are known to be metal-based materials and organic dye-based materials.The former has the advantage of high reflectivity and high contrast during recording. In order to form a film as a recording layer, a vacuum technique such as vapor deposition or sputtering is required, and a problem remains in the development of card production on the premise of mass production and issuance.

In view of the above, organic dyes, particularly dye-based recording materials, can be formed into a film as a coating material by using an appropriate solvent, and thus can be said to be superior to metal-based materials in view of mass productivity.

Examples of organic dyes include anthraquinone, naphthoquinone, triphenylmethane, carbocyanine, merocyanine, xanthene, azo, azine, thiazine, oxazine, phthalocyanine, squarylium, and indoaniline dyes. Is mentioned. Above all, indoaniline metal complex dyes have a large molecular extinction coefficient, so that a film having a high reflectivity can be obtained at the time of film formation.

Incidentally, even with the same write-once optical recording medium, the recording / reproducing apparatus differs depending on whether the medium has a disk shape or a card shape. That is, in the case of a disk, recording and reproduction are performed by rotational movement, whereas in the case of a card, linear reciprocation is performed. This means that, regardless of whether the optical head moves or the card medium moves, the moving speed must be slower than the linear speed in the case of rotation due to restrictions on the device. That's what it means.

Further, in the case of a card medium, when recording / reproduction is not performed, the laser head is stopped at a part of the card, and the reproduction laser light is continuously irradiated on a part of the recording layer continuously. Therefore, the card medium is required to have extremely high resistance to laser light and heat as compared with a disk medium.

[Problems to be solved by the invention]

One disadvantage of organic dye-based recording materials is that
Light degradation due to repeated reading of a reproduction laser beam is known. In this regard, from elucidation of the degradation mechanism,
By adding a singlet oxygen quencher or the like, the problem has been solved to a level that does not cause a practical problem in a disk medium. Of course, this point is inevitable even when an organic dye-based material is applied to a card. When the addition of a quencher to a card medium is considered, although the optical deterioration is reduced, the melting point of the quencher itself is not so high, and as a result, the melting point of the recording layer is reduced. As described above, since the scanning speed of the reproduction laser beam is low in the card medium, it has become clear that the reproduction signal is deteriorated due to the effect of heat generated at that time. This effect is even stronger when the laser head is stationary.

One of the easy solutions to this problem is to reduce the intensity of the read laser beam when the laser head is stationary. However, in this case, since the intensity of the reproduction light decreases, an error occurs due to the load on the amplifier after the detector and the unstable oscillation of the laser as the light source. The rate increases.

Further, as another method, it is conceivable to add an arbitrary material having no absorption capacity with respect to the wavelength of the reading laser beam.
However, in that case, it is difficult to form a film by coating due to the difference in solubility and compatibility with the dye as the recording material. Further, disadvantages such as a large decrease in the reflectance of the recording layer occur.

[Means for solving the problem]

The optical card described in the present invention is characterized by using an indoaniline metal complex dye having a structure having a bifunctional acrylate or methacrylate group in which the dye of the recording layer can be independently polymerized and crosslinked. Things.

The basic configuration of the optical card of the present invention will be described with reference to the drawings. FIG. 1 shows a sectional view of the optical card. The surface hardened layer 1 is usually made of an ultraviolet curable resin such as urethane acrylate or epoxy acrylate, and can be provided as necessary.

The transparent substrate 2 is usually made of polycarbonate resin, acrylic resin, epoxy resin, polyester resin, or the like.
A guide groove (not shown) for enabling tracking when reading with laser light is usually provided.

The optical recording layer 3 in FIG. 1 includes organic dyes of carbocyanine type, naphthoquinone type, anthraquinone type, phthalocyanine type, naphthalocyanine type, indigo type, indoaniline type and the like, and is provided by a vapor deposition method or a coating method. However, optical cards are slower in writing and reproducing laser light scanning speed due to device limitations than optical disks, and the reproducing laser light is stationary on the recording layer. Higher thermal resistance than an optical recording medium for use. Accordingly, an indoaniline metal complex dye having a polymerizable functional group represented by the following general formula [I] is used in the optical recording layer of the present invention.

General formula [I] (Wherein, R ₁ represents a hydrogen atom or a methyl group; R ₂ acroyl group, methacryloyl group, N-methyl-N-methylacroylamino group, N-methyl-N-methylmethacryloylamino group, N- Ethyl-N-methylacryloylamino group, N-
Ethyl-N-methylmethacryloylamino group, N-ethyl-
N-ethyl acroylamino group and N-ethyl-N
-Represents an ethyl methacryloylamino group. Further X ^- is, I ^-, B
_{^{r -, Cl -, ClO 4}} - represents an anion such as. M represents a metal ion such as Ni, Cu, and Co. The reason that the indoaniline metal complex dye is excellent as an optical recording layer of an optical card is that the dye itself has a metal complex structure and thus is strong against light deterioration. In addition, compared to other dyes such as cyanine-based dyes, it has no melting point and has a relatively high decomposition temperature, so it has excellent thermal characteristics, and it has high reflectance compared to other dyes, so it has optical characteristics. Is also excellent. Further, since the dye of the present invention has a polymerizable functional group, it is considered that the dye molecule is polymerized by heat or light such as laser light to form a crosslinked structure, and the dye is further stabilized against heat. Further, after the formation of the optical recording layer, the dye molecules can be polymerized by irradiation with ultraviolet rays or electron beams, whereby the thermal characteristics of the optical recording layer are further improved.

The indoaniline metal complex dye represented by the general formula [I] has absorption in a wavelength band of 700 nm to 800 nm. The optical recording layer 3 can be provided by dissolving the dye represented by the general formula [I] in an appropriate solvent and spin coating, gravure printing, a roll coater or the like. Further, a polymerization initiator is added to the optical recording layer 3 and, after coating, the optical recording layer 3 is cured by irradiating ultraviolet rays, or the optical recording layer 3 is cured by irradiating an electron beam. And the thermal resistance is further improved.

The protective layer 4 in FIG. 1 has a purpose of protecting the optical recording layer 3,
It is used as needed for the purpose of increasing the heat resistance of the optical recording layer 3. Various resin layers can be considered as the protective layer 4 used here. In particular, after forming the optical recording layer 3, an ultraviolet curable resin or an electron beam curable resin is applied, and the optical recording layer 3 and the protective layer 4 are simultaneously cured by irradiating an ultraviolet ray or an electron beam together with the optical recording layer 3. Thermal resistance is improved. The reason that such an ultraviolet curable resin or an electron beam curable resin improves the thermal resistance of the optical recording layer 3 as a protective layer is that the dye itself of the optical recording layer 3 used in the present invention has polymerizability. Therefore, at the interface between the optical recording layer 3 and the protective layer 4 due to the irradiation of ultraviolet rays or electron beams, the dye molecules of the optical recording layer 3 and the oligomer of the resin of the protective layer 4 have a direct cross-linking structure. It is considered that the adhesion between the recording layer 3 and the protective layer 4 is improved, and the optical recording layer 3 is stabilized.

The adhesive layer 5 shown in FIG. 1 is made of an epoxy, acrylic, urethane or other resin.

The backing substrate 6 is made of polyvinyl chloride, polystyrene,
Examples include sheets and plate-like materials such as polyester.

[Action]

Since the optical recording layer in the invention uses a dye having a polymerizable functional group, the functional group is crosslinked, so that it has better thermal resistance than an optical recording layer made of a dye having no functional group.

In addition, if the protective layer 4 is provided, the optical recording layer 3 is cured and cross-linked at the same time, thereby stabilizing the optical recording layer 3 and further improving the thermal resistance of the reproduction laser light and the like as compared with using the optical recording layer 3 alone. Can be improved.

Therefore, the optical card according to the present invention has excellent thermal stability with respect to the reproduction laser light, has little reproduction deterioration, has stable pit formation by irradiation of the recording laser light, is faithful to the recorded information, and has less uneven recording. Reproduction is possible.

Further, if an indoaniline metal complex dye is used as a material for the optical recording layer, the reflectance of the dye is high, and 700 nm to 8 nm.
Optical characteristics such as having an absorption band in a long wavelength band of 00 nm are also excellent. In addition, since it has a higher decomposition point than organic dyes such as carbocyanine, which are the materials of ordinary optical recording layers, it has excellent thermal resistance.

Comparative Example 1 Comparative Example 1 will be described with reference to FIG.

As a surface hardened layer 1, a transparent groove 2 having a width of 0.4 μm and a depth of 0.2 μm was provided on a 0.4-mm-thick polyacryl substrate having a 0.2-μm-thick polyurethane resin by a thermal compression molding method.

Next, 1 ', 1', 3,3,3 ', 3'-hexamethyl-2,2'-
Indian tricarbocyanine iodide and bis (trichlorobenzenedithiol) nickel tetra (t-butyl)
A 1.5% solution was prepared by using ammonium in a solvent of cyclohexanone at a ratio of 1: 1. The solution was applied on the transparent substrate 2 by spin coating to obtain an optical recording layer 3. At this time, the maximum absorption wavelength of the coating film was about 790 nm, and the reflectance was about 50%.

A polystyrene resin (manufactured by Sanyo Chemical Co., Ltd.)
ST-95) was prepared in a 10% solution of toluene, and applied by a spin coating method to form a protective layer 4.

The protective layer 4 and the backing substrate 6 made of a rigid vinyl chloride sheet
An epoxy-based adhesive (araldite manufactured by Ciba-Geigy) was attached as the adhesive layer 5 and punched into a card size to produce an optical card.

The optical card manufactured in this manner was recorded with a semiconductor laser (830 nm, 2 KHz) at a speed of 80 mm / sec while changing the write output, and was reproduced with a reproduction output of 0.6 mW, as shown in FIG. A good sensitivity curve was obtained.
Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW. After approximately several hundred readings, the intensity of the reproduction signal was approximately 60%.
%.

Next, the deterioration of the reflectance when the reproduction laser light was stopped at a part of the optical card was measured, and the results are shown in FIG. The vertical axis of the figure shows the relative reflectance when the initial reflectance is 1.

(Comparative Example 2) The following structural formula was used as the optical recording layer 3 The indoaniline metal complex dye represented by the formula (1) was prepared as a 1.5% solution using cyclohexanone as a solvent, and applied onto the transparent substrate 2 by spin coating to obtain an optical recording layer 3. At this time, the maximum absorption wavelength of the coating film was about 790 nm, and the reflectance was about 50%.

A polystyrene resin (manufactured by Sanyo Chemical Co., Ltd.)
ST-95) was prepared in a 10% solution of toluene, and applied by a spin coating method to form a protective layer 4.

Based on the optical recording layer 3 and the protective layer 4, a DRAW-type optical card was manufactured in the same manner as in Comparative Example 1, and recording and reproduction were performed under the same conditions as in Comparative Example 1, as shown in FIG. A good sensitivity curve was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser beam was stopped at a part of the optical card was measured, and the results are shown in FIG.

Embodiment 1 An embodiment will be described with reference to FIG.

As a surface hardened layer 1, a transparent substrate 2 was obtained by providing a guide groove having a width of 0.3 μm and a depth of 0.2 μm on a 0.4 mm thick polyacryl substrate having a polyurethane resin having a thickness of 0.2 μm by a thermal compression molding method.

Next, the following structural formula The indoaniline metal complex dye represented by the formula (1) was prepared as a 1.5% solution using cyclohexanone as a solvent, and applied onto the transparent substrate 2 by spin coating to obtain an optical recording layer 3. At this time, the maximum absorption wavelength of the coating film is about 790 nm and the reflectance is about 4
8%.

Polystyrene resin (manufactured by Sanyo Chemical Co., Ltd.)
ST-95) was prepared in a 10% solution of toluene, and applied by a spin coating method to form a protective layer 4.

The optical card manufactured in this manner was recorded with a semiconductor laser (830 nm, 2 KHz) at a speed of 80 mm / sec while changing the lower write output, and reproduced with a reproduction output of 0.6 mW, as shown in FIG. Such a good sensitivity curve was obtained. Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser beam was stopped at a part of the optical card was measured, and the results are shown in FIG. The vertical axis in the figure shows the relative reflectance when the initial reflectance is 1.

Example 2 For the optical recording layer 3, 1.5% of the same indoaniline metal complex dye as in Example 1 was used, using cyclohexanone as a solvent.
A solution was prepared, applied onto the transparent substrate 2 by spin coating, and irradiated with about 5 Mrad of electron beam to form the optical recording layer 3. The maximum absorption wavelength of the coating film at this time is about 790n
At m, the reflectivity was about 48%.

A polystyrene resin (manufactured by Sanyo Chemical Co., Ltd.)
ST-95) was prepared in a 10% solution of toluene, and applied by a spin coating method to form a protective layer 4.

Based on the optical recording layer 3 and the protective layer 4, a DRAW-type optical card was manufactured in the same manner as in the first embodiment, and recording and reproduction were performed under the same conditions as in the first embodiment, as shown in FIG. A good sensitivity curve was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times. Next, the deterioration of the reflectance when the reproduction laser beam was stopped at a part of the optical card was measured, and the results are shown in FIG.

Example 3 The following structural formula was used as the optical recording layer 3 An indoaniline metal complex dye represented by formula (1) is prepared as a 1.5% solution using cyclohexanone as a solvent, applied on a transparent substrate 2 by spin coating, and irradiated with an electron beam of about 5 Mrad to obtain an optical recording layer. 3 were provided. At this time, the maximum absorption wavelength of the coating film was about 791 nm, and the reflectance was about 47%.

On this optical recording layer 3, a protective layer 4 similar to that of the first embodiment is provided, and a DRAW-type optical card is manufactured by the same method as that of the first embodiment. A good sensitivity curve as shown in FIG. 10 was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser light was stopped on a part of the optical card was measured, and the results are shown in FIG.

(Example 4) The following structural formula was used as the optical recording layer 3. Indoaniline metal complex dye represented by the formula and an ultraviolet polymerization initiator (Darocur 1116 manufactured by Merck) are added at a ratio of 2% to the dye, and a cyclohexanone is used as a solvent to prepare a 1.5% solution. It was applied on the transparent substrate 2 by a coating method. Next, the optical recording layer 3 was provided by irradiating ultraviolet rays. At this time, the maximum absorption wavelength of the coating film was about 730 nm, and the reflectance was about 41%.

On this optical recording layer 3, a protective layer 4 similar to that of the first embodiment is provided, and a DRAW-type optical card is manufactured by the same method as that of the first embodiment. A good sensitivity curve as shown in FIG. 12 was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser beam was stopped at a part of the optical card was measured, and the results are shown in FIG.

(Example 5) For the optical recording layer 3, the same indoaniline metal complex dye as in Example 1 was prepared as a 1.5% solution using cyclohexanone as a solvent, and applied to the transparent substrate 2 by spin coating.

Next, as the protective layer 4, an electron beam-curable oligomer (Kyoeisha Yushi Kagaku Kogyo, DCP-A) is applied onto the optical recording layer 3 by a spin coat method, and irradiated with an electron beam of about 5 Mrad to form the protective layer 4 together with the optical recording layer 3. The protective layer 4 was cured and provided.

At this time, the maximum absorption wavelength of the coating film was about 790 nm, and the reflectance was about 48%.

Based on the optical recording layer 3 and the protective layer 4, a DRAW-type optical card was manufactured in the same manner as in the first embodiment, and recording and reproduction were performed under the same conditions as in the first embodiment, as shown in FIG. A good sensitivity curve was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser light was stopped on a part of the optical card was measured, and the results are shown in FIG.

(Example 6) The following structural formula was used as the optical recording layer 3. Indoaniline metal complex dye represented by the formula and an ultraviolet polymerization initiator (Darocur 1173 manufactured by Merck) are added at a ratio of 2% to the dye, and a 1.5% solution is prepared using cyclohexanone as a solvent, It was applied on the transparent substrate 2 by a coating method.

Next, as a protective layer 4, an ultraviolet-curing oligomer (Nippon Kayaku, HDDA) was added with an ultraviolet-polymerization initiator (Darocur 1173, manufactured by Merck) at a ratio of 2% to the oligomer.
Was applied onto the optical recording layer 3 by spin coating. By irradiating the optical recording layer 3 and the protective layer 4 with ultraviolet light,
The protective layer 4 was cured together with the optical recording layer 3.

At this time, the maximum absorption wavelength of the coating film was about 710 nm, and the reflectance was about 40%.

Based on the optical recording layer 3 and the protective layer 4, a DRAW-type optical card was manufactured in the same manner as in the first embodiment, and recording and reproduction were performed under the same conditions as in the first embodiment, as shown in FIG. A good sensitivity curve was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser light was stopped at a part of the optical card was measured, and the results are shown in FIG.

(Example 7) The following structural formula was used as the optical recording layer 3. A cyclohexane was used as a solvent to prepare a 1.5% solution of the indoaniline metal complex dye represented by the formula (1), and the solution was applied onto the transparent substrate 2 by spin coating.

Next, as a protective layer 4, an electron beam curable oligomer (1,6HX-A, manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) is applied onto the optical recording layer 3 by a spin coating method, and irradiated with an electron beam of about 5 Mrad. The protective layer 4 was provided together with the recording layer 3 by curing.

At this time, the maximum absorption wavelength of the coating film was about 781 nm, and the reflectance was about 45%.

Based on the optical recording layer 3 and the protective layer 4, a DRAW-type optical card is manufactured in the same manner as in the first embodiment, and recording and reproduction are performed under the same conditions as in the first embodiment, as shown in FIG. A good sensitivity curve was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser light was stopped on a part of the optical card was measured, and the results are shown in FIG.

(Example 8) As the optical recording layer 3, the same indoaniline metal complex dye as in Example 1 and an electron beam-curable oligomer (M-240, manufactured by Toa Gosei Chemical Co., Ltd.) were used at a weight ratio of 2: 1 with cyclohexanone as a solvent. A 1.5% solution was prepared and applied to the transparent substrate 2 by spin coating.

Next, the optical recording layer 3 was cured by irradiation with an electron beam.

At this time, the maximum absorption wavelength of the coating film was about 791 nm, and the reflectance was about 28%.

Based on the optical recording layer 3 and the protective layer 4 of Example 1,
When a DRAW-type optical card was manufactured in the same manner as in Example 1, and recording and reproduction were performed under the same conditions as in Example 1, a good sensitivity curve as shown in FIG. 20 was obtained.

Then, reproduction was repeatedly performed with a reproduction laser output of 0.6 mW, but no change was observed in the reproduction signal even after reading about 50,000 times.

Next, the deterioration of the reflectance when the reproduction laser light was stopped on a part of the optical card was measured, and the results are shown in FIG. 21.

〔The invention's effect〕

The optical card according to the present invention has little deterioration even with repeated reproduction or stationary reproduction laser light, and has excellent recording sensitivity and high reliability.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a comparative example and an example of an optical card of the present invention. FIGS. 2 and 4 are graphs showing sensitivity curves of the optical card of the comparative example, and FIGS. 6, 8, 10, 12, 14, 16, 18, and 2.
FIG. 0 is a graph showing a sensitivity curve of an embodiment of the optical card of the present invention, and FIGS. 3 and 5 are graphs showing a deterioration curve with respect to a reproduction laser beam of the embodiment of the optical card of the comparative example; , 11,13,
FIGS. 15, 17, 19 and 21 are graphs showing deterioration curves of the optical card of the present invention. DESCRIPTION OF SYMBOLS 1 ... Surface hardened layer 2 ... Transparent substrate 3 ... Optical recording layer 4 ... Protective layer 5 ... Adhesive layer 6 ... Backing substrate

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-1244491 (JP, A) JP-A-3-214152 (JP, A) JP-A-2-187467 (JP, A) JP-A-63-1988 237992 (JP, A) JP-A-63-227569 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7/24 572 G11B 7/24 516

Claims (4)

(57) [Claims] 1. An optical card having at least one optical recording layer sandwiched between two substrates, at least one of which is permeable to recording / reproducing light, wherein the recording layer is independently polymerized and crosslinked. An optical card characterized by being an indoaniline metal complex dye having a structure having a possible bifunctional acrylate or methacrylate group. 2. The optical card according to claim 1, wherein after the optical recording layer is formed by coating, the optical recording layer is cured by irradiation with ultraviolet rays or electron beams. 3. After the optical recording layer is formed by coating, an ultraviolet curable resin oligomer or an electron beam curable resin oligomer is further coated as a protective layer, and cured by irradiating an ultraviolet ray or an electron beam simultaneously with the optical recording layer. The optical card according to claim 1, wherein the optical card is provided. 4. The optical recording layer is formed by mixing and coating the material of the optical recording layer and an ultraviolet curable resin oligomer or an electron beam curable resin oligomer, and then irradiating an ultraviolet ray or an electron beam to cure the optical recording layer. Item 2. The optical card according to item 1.