JP3299994B2 - Optical recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, and more particularly to a recordable single-plate optical recording medium. More specifically, a single-plate optical recording medium comprising a dye-containing recording layer and a protective layer,
The present invention relates to an optical recording medium on which various information can be recorded by a laser beam.

[0002]

2. Description of the Related Art Both recordable and erasable optical recording media have been put to practical use. However, in order to protect the recording layer, the conventional recordable optical recording medium which has already been put into practical use usually has the recording layer side inward, and the same substrate or protective substrate is bonded directly or with an air gap provided. It was a recording medium (lamination medium). However, the conventional laminating medium not only has the disadvantage of requiring a complicated laminating step, but also has a heavy load on the drive motor due to the heavy weight of the medium. In order to improve these disadvantages, development of a single-plate type recordable optical recording medium has been attempted. In a single-plate optical recording medium, it is necessary to provide a protective layer on the recording layer in order to protect the recording layer, and a hard coat agent is usually applied. However, on top of this protective layer ,
Need arises peeling these labels or tape after sticking the label and adhesive tape to. The conventional protective layer film has a problem that the recording layer or the protective layer peels off when the label or the tape is peeled off, the reflectance of the recording film changes, and the error rate increases. In order to improve this problem, it has been proposed to add an additive to, for example, a hard coat agent. However, there is a problem that the use of the additive causes a decrease in adhesion of a print provided on the protective layer. Further, the conventional protective layer film has a problem in durability. In other words, only the hardness of the protective film is regarded as important, and it is lacking in protecting the recording layer from humidity.

[0003]

SUMMARY OF THE INVENTION The present inventors have proposed a single plate having a protective layer provided directly on a recording layer by adding a certain curable compound to an active energy ray-curable resin used for the protective layer. In optical recording media of recordable type, the problems such as peeling of the recording layer and protective layer when peeling labels and tapes, changes in reflectance of the recording layer, and an increase in error rate, which were difficult in the past. The present invention has been found to be an optical recording medium which can be solved, has excellent adhesion to the printing provided on the surface of the protective layer, and has more excellent durability.

[0004]

That is, the present invention provides a transparent injection-molded resin substrate , a recording layer and an reflective layer containing an organic dye on the substrate , and both the layers are provided on the both layers . in a single-plate type optical recording medium comprising a protective layer, the protective layer is .gamma. (main
Tacryloxypropyl) trimethoxysilane, γ- (meth
Tacryloxypropyl) methyldimethoxysilane, γ-
(Methacryloxypropyl) trimethylsilane, γ-
(Methacryloxypropyl) triphenylsilane, vinyl
Rutrimethoxysilane, vinyltriethoxysilane, vinyl
Niltris (β-methoxy-ethoxy) silane, vinyl
Triphenylsilane, silicone (meth) acrylate
An active energy ray-curable resin containing 0.5 to 20% by weight of a curable compound selected from the group consisting of: As the transparent injection molded substrate used in the present invention,
Those that transmit light for recording and reading signals are preferable. It is desirable that the light transmittance is 85% or more and the optical anisotropy is small. For example, acrylic resin, polycarbonate resin, polyamide resin,
A preferred example is a substrate using a thermoplastic resin such as a vinyl chloride resin or a polyolefin resin. Among these, acrylic resin, in terms of mechanical strength of the substrate, ease of providing guide grooves and read-only signals, etc.,
Injection molded resin substrates of polycarbonate resin and polyolefin resin are preferred, and polycarbonate resin substrates are more preferred.

[0005] The shape of these substrates may be plate-like or film-like, circular or card-like. Of course, the surface of the substrate may have guide grooves indicating recording positions, pits indicating recording positions, and pits for partially read-only information. Such guide grooves, pits, and the like are preferably provided when a substrate is formed by injection molding or casting, but can also be provided by applying an ultraviolet curable resin onto the substrate, overlapping with a stamper, and performing ultraviolet exposure. . In the recording medium of the present invention, on the transparent injection molded resin substrate,
Recording layer, reflective layer , protective layer or reflective layer, recording layer, protection
The layers are sequentially laminated, and the organic color used for the recording layer is
As is the elementary, cyanine, organic pigments such as phthalocyanine
Serial RaYoshimi Masui or terms of the ease of formation of the Rokumaku. Also rather it may also be stacked further on induction conductor layer under or on the recording layer, as medium high reflectance is required to obtain gold, provided aluminum, silver, a reflective layer such as copper. Also it is possible than Ranaru or recording layer and the reflective layer compatibility also contains an organic dye as described above with commercially available CD players.

[0006] In the present invention Oh recording layer such as described above is
Alternatively , a protective layer is further provided on the reflective layer to protect the recording layer. As the resin used for the protective layer,
Hard coating agent and the like that have been developed in order to prevent-out with the resin wound. Various types of hard coat agents have been developed, but active energy ray-curable resins such as ultraviolet curable and electron beam curable resins are used because they have excellent workability and do not contain a solvent. As a specific example of the active energy ray-curable resin used as the base of the protective layer in the present invention, a so-called (meth) acrylate-based ultraviolet-curable resin is preferable. In the present invention, the active energy ray-curable resin contains the curable compound in an amount of 0.5 to 20% by weight.
% Is added pressure to Ru is used.

[0007] Hardness of compounds that are used in the present invention
Is, .gamma. (methacryloxypropyl) trimethoxysilane, .gamma. (methacryloxypropyl) methyldimethoxysilane, .gamma. (methacryloxypropyl) trimethylsilane, .gamma. (methacryloxypropyl) triphenyl silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl tris (beta-methoxy - ethoxy) silane, vinyl triphenyl silane, silicone (meth) Ru acrylate der.

These compounds generally have an appropriate compatibility with the active energy ray-curable resin and, after the resin is cured, are copolymerized with each other, so that they do not bleed to the surface of the resin. Therefore, even when printing is performed on the surface of the protective layer using an ultraviolet curable ink or the like, the adhesion between the protective layer and the printed layer does not decrease. In the invention, the addition amount before Kikata-resistant compound content in the active energy ray curable resin 0.
5 to 20% by weight. When the content of the compound is less than 0.5% by weight, the effect of the present invention is not exhibited. On the other hand, when the content of the compound exceeds 20% by weight, the compatibility with the active energy ray-curable resin is deteriorated, and the adhesion to the printing layer on the protective layer is reduced. Moreover, it is not economically preferable. In the present invention, the thickness of the recording layer is usually from 30 to 700 nm, preferably from 50 to 500 nm. The protective layer provided on the recording layer is a layer having a function of protecting the recording layer of the single-plate optical recording medium, and is usually 1 μm, preferably a hard film having a thickness of 2 μm or more. good. Although there is no particular upper limit for the film thickness, it is usually 100
μm or less. The optical recording medium of the present invention can be further printed on the protective layer.

[0009]

EXAMPLES The present invention will be described below in more detail with reference to examples, but embodiments of the present invention are not limited thereto. Examples 1-3, Comparative Examples 1-2 Spiral guide grooves having a thickness of 1.2 mm and a diameter of 120 mm (depth 70 nm, width 0.6 μm, pitch 1.6 μm)
1,1'-dipropyl-3,3,3 at the center of the surface of the injection-molded polycarbonate resin substrate having the guide groove having
After dropping a 6% by weight solution of 3 ', 3'-tetramethyl-5,5'-dimethoxyindodicarbocyanine iodide dye in diacetone alcohol, the resin substrate was rotated at 1000 rpm for 10 seconds. Next, this resin substrate was dried in an atmosphere at 40 ° C. for 10 minutes to form a 120 nm dye layer substantially composed of only a cyanine dye on the resin substrate. Next, gold was formed on this dye layer by a sputtering method, and a reflective layer having a thickness of 100 nm was provided. Further, on this reflective layer, active energy ray curing was carried out by adding a compound of the type shown in Table 1 below in an amount shown below to an ultraviolet-curable resin (Daikyu Clear EX-704, manufactured by Dainippon Ink Co., Ltd.). A resin is applied by spin coating, irradiated with ultraviolet light, an 8 μm protective layer is laminated, and a label is printed on the protective layer using an ultraviolet curable ink, and the optical recording medium of the present invention as a final product form Was made. A linear measurement of 1, 4 m / s, 7 m
The EFM modulation signal was recorded under the recording power condition of W. In order to observe the separation of the recording layer of the medium after the recording , a cellophane tape was attached to the printing surface and then the recording layer was separated. In any of the examples of the present invention, the separation of the recording layer was not observed. Also, no change was observed in the reflectance and error rate using the focused laser beam through the substrate. Further, after leaving this medium at 90 ° C. and 85% RH for 2000 hours, a cellophane tape peeling test was performed, but no recording layer was peeled. Also, no change in reflectance or error rate was observed. On the other hand, in Comparative Example 1 in which nothing was added, the recording layer was partially peeled. The reflectance was measured at the portion where the recording layer was not peeled off.
It was 0% lower. 20 ° C, 85% RH
In the medium left for 00 hours, the recording layer was peeled over the entire surface of the portion where the tape peeling test was performed. Even in the part where the tape peeling test was not performed, the reflectance was reduced by about 30%, and the error rate was also increased by about 50 times. On the other hand, in Comparative Example 2, peeling occurred between the printing layer and the protective layer.

[0010]

[Table 1]

[0011] Examples 4-5, instead of in the dye solution in Comparative Example 3 Example 1, Pd-tetra -
3.5% by weight of a (t-butylcyclohexyloxy) phthalocyanine bromide (average: 3.0 / molecule) dye
And a compound of the type shown in Table 2 below in an amount shown below in an ultraviolet curable resin (Dai Nippon Ink Co., Ltd., Daicure Clear SD-
Using the active energy ray-curable resin added in 17),
When a medium was prepared and evaluated in the same manner as in Example 1, no print-off of the recording layer was observed in any of the examples of the present invention. No change was observed in both the reflectance and the error rate. Furthermore, there was no abnormality even after the moist heat test. On the other hand, in Comparative Example 3 in which nothing was added, the recording layer was partially peeled. The reflectance was measured at the portion where the recording layer was not peeled off, but the reflectance was reduced by about 30%, and the error rate was increased about twice. After the heat and moisture resistance test, there was no abnormality in the reflectance and the error rate in the portion where the tape peeling test was not performed, but the recording layer was peeled over the entire surface in the portion where the tape peeling test was performed.

[0012]

[Table 2]

[0013]

As is clear from the examples, in the present invention, a cellophane tape was attached to the surface of the protective layer of the optical recording medium by adding a specific curable compound to the resin used for the protective layer. Later, even if this tape is peeled,
No peeling of the recording film occurs, and no change in reflectance and error rate is observed. Further, no abnormality occurs even when the tape is peeled off after being left for a long time under the moisture and heat resistant condition. Also,
Excellent film formability due to the organic dye of the recording layer, providing a reflective layer
High reflectivity, compatible with commercial CD players
Sex is also possible.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Sumio Hirose 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals Co., Ltd. (56) References JP-A-2-53241 (JP, A) JP-A-63 -47195 (JP, A) JP-A-60-117430 (JP, A) JP-A-4-129799 (JP, A) JP-A-4-320462 (JP, A) JP-A-3-79674 (JP, A) JP-A-61-21113 (JP, A)

Claims (2)

(57) [Claims] 1. A transparent injection molded resin substrate, organic on the substrate
In a single-plate optical recording medium comprising a recording layer and a reflective layer containing an organic dye, and a protective layer provided on both of the layers, the protective layer is γ- (methacryloxypropyl) trimethoxy.
Silane, γ- (methacryloxypropyl) methyl dimethoate
Xysilane, γ- (methacryloxypropyl) trimethyl
Silane, γ- (methacryloxypropyl) triphenyl
Silane, vinyltrimethoxysilane, vinyltriet
Xysilane, vinyl tris (β-methoxy-ethoxy)
Silane, vinyltriphenylsilane, silicone (meth
(T) An active energy ray-curable resin containing a curable compound selected from the group consisting of acrylates in an amount of 0.5 to 20% by weight. 2. The single-plate optical recording medium according to claim 1, wherein the active energy ray-curable resin is a (meth) acrylate-based ultraviolet curable resin.