JPS60127542A - Recording and regenerating photodisc type record carrier - Google Patents

Abstract

PURPOSE:To obtain a disc small in optical and mechanical strain by forming a UV-hardenable resin layer contg. multifunctional oligo-ester acrylate and specified unifunctional acrylate on one side of a transparent resin base, and further, laminating a recording layer and a protective resin layer in this order on said resin layer. CONSTITUTION:A high-quality photodisc type record carrier is obtained by preparing a UV-hardenable resin soln. 3 contg. a unifunctional acrylate represented by the formula, n being 1-3, and the reaction product obtained by esterifying at least 3 kinds of compds. of polyhydric alcohol, polycarboxylic acid, and acrylic acid; coating a stamper 5 having volute or concentrical guide grooves with said soln. 3; pressing a transparent homogeneous resin plate 1 made of polymethacrylate or the like onto the coated stamper 5 by inserting spacers 6; exposing this resin soln. 3 to UV rays 8 to harden it and join it with the base 1 into one body; separating the base 1 and the hardened resin 3 from the stamper 5, and finally, laminating a thin recording film layer 4 made of Te oxide or the like, and a protective resin layer 2 in succession on the hardened resin 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used to record signals such as video signals and acoustic signals on a recording thin film layer using a laser beam, and to reproduce the recorded signals again using a laser beam. The present invention relates to an optical disk type record carrier for recording and reproduction.

2. Description of the Related Art Conventional 4'y System Structure and Problems In recent years, user-writable write-once optical discs for still image files and text files have become popular, as well as internal-only optical discs such as compact discs and video discs. A read-only optical disc has signals formed as pits on a substrate. On the other hand, in write-once optical discs, only a guide groove is formed before recording, and a laser beam is irradiated along the guide groove during recording, resulting in an optical state change in the recording thin film, which becomes a signal.

Methods for forming the guide groove include a stamping method, an injection molding method, and a method of forming the guide groove using an ultraviolet curable resin. An ultraviolet curable resin is injected between the master and the base material, on which guide grooves have been previously provided, and ultraviolet rays are irradiated to form guide grooves on the surface of the ultraviolet curable resin (hereinafter referred to as replica removal).

In general, UV-curable resins improve productivity by curing in a short time; they are solvent-free, so they are non-polluting and resource-saving; they cure near room temperature and can be applied over many months when heating is inappropriate; It has advantages such as low energy consumption and low operating costs. Furthermore, since the ultraviolet curable resin used as a material for optical disks is in liquid form, it can be filtered and it is possible to obtain a resin that does not contain foreign substances such as dust, and it is evenly distributed in every corner of the guide groove, reproducing the guide groove. You can take a photo of it moving around. Unfortunately, anisotropy inside the resin is less likely to occur, and optical and mechanical distortions are also less likely to occur.

However, when taking replicas, it is either done under relatively high humidity, or as replicas are removed repeatedly, resin may partially adhere to the master disc, and this adhesion can cause a large amount of rough rough-out on the finished disc. This is a contributing factor. For this reason, there is a strong demand for an optical disk-type record carrier for recording and reproducing using an ultraviolet curing resin that does not cause partial staining of the resin on the master even if replicas are taken repeatedly.

Further, the cured resin forming the guide groove is required to have an extremely small degree of thermal deformation so that the shape of the guide groove does not change due to heat.

OBJECTS OF THE INVENTION The object of the present invention is to provide an optical disc-type record carrier for cows that satisfies these demands, is free from manufacturing troubles, and is of excellent quality.

Structure of the Invention The optical disc type recording medium for internal recording of the present invention comprises an optically transparent and homogeneous resin base material, and an ultraviolet curable resin layer having spiral or concentric guide grooves on one side of the resin base material. A recording thin film layer whose optical state changes when irradiated with laser light and a resin protective layer are sequentially laminated, and the ultraviolet ray curable resin layer is composed of polyfunctional oligoester acrylate and the following monofunctional compound represented by the following structural formula. It is obtained by curing a resin composition containing acrylate I.

However, by using the ultraviolet curable resin composition, the stamper can be removed even if replicas are made repeatedly.
It has been found that the resin does not partially adhere to the disk, and as a result, the dropout of the finished disk can be significantly reduced.

It has been found that by appropriately combining Kokeda polyfunctional acrylate-1 and monofunctional acrylate, a cured product with almost no change in elastic modulus at 1ooC or less can be made.

Moreover, the optical distortion in the path of the laser beam used for signal recording and heating is small, and there is a simple method for cleaning the ultraviolet curable resin composition before curing (for example, pressurized P
It is possible to completely eliminate foreign matter in the vicinity of the recording island/film layer by handling the film, resulting in an optical disk type record carrier for recording and reproducing of excellent quality.

Various additives can be added to the ultraviolet curable resin composition in order to modify its properties within a range that does not impair the removability from the stamper.

/Kotoe is the defoaming property of liquid resin, defoaming agents to improve wetting with the stamper, surfactants such as wetting agents, non-reactive thermoplastic resins to reduce curing shrinkage, and ultraviolet rays. There are thermosetting catalysts such as organic peroxides that effectively utilize the heat generated from the lamp during irradiation.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a sectional view showing the structure of an optical disk type record carrier for recording and reproducing according to the present invention. In Fig. 1, 1 is an optically transparent and homogeneous resin base material, 2 is a resin protective layer, 3 is an ultraviolet curable resin layer having spiral or concentric guide grooves, and 4 is an optically transparent resin base material that is optically transparent by laser beam irradiation. It is a recording thin film layer whose state changes. As the resin base material 1, a disc-shaped member made of an optically transparent and homogeneous material, such as a thermoplastic resin such as polymethacrylic ester resin or polycarbonate resin, is used. As the ultraviolet curable resin composition, 80 parts by weight of Alonisox M-aoeo (trade name, manufactured by Toagosei Chemical Industry Co., Ltd.), Aroninox M~1
○1 (Toagosei Chemical System, product name) 20! fit part and 3M parts of benzyl dimethyl ketal. As the recording thin film layer 4, a light-absorbing low oxide, such as tellurium low oxide Teox (mainly containing 0(x(2)), is used.

The manufacturing method of the optical disc-type record carrier for recording and reproduction constructed as described above will be explained below with reference to FIG. 2.

First, a part or the entire surface of the stamper 5 having spiral or concentric guide grooves is coated with a liquid resin that can be cured by ultraviolet irradiation, and then an optically transparent and homogeneous resin is coated on top of the liquid resin. The base material 1 is crimped with a spacer 6 in between so that the liquid resin has a uniform thickness. Next, the liquid resin is cured by irradiating ultraviolet rays 8 (from an ultraviolet lamp 7) through the substrate 1, and then the substrate is peeled off from the stamper together with the cured resin 3 adhering to it, thereby obtaining a disk. In order to use the obtained disk with guide grooves as an optical disk type record carrier for recording and reproduction, a low tellurium oxide Te0x (○<X<2) is added as a recording thin film layer to the surface of the ultraviolet curable resin layer having guide grooves. is provided by vacuum steaming NK. Furthermore, as a resin protective layer, a sheet preferably made of the same material as the resin base material is laminated to the recording thin film layer using an ultraviolet curable resin, and is cured by ultraviolet irradiation and bonded, or a sheet made of the same material as the resin base material is bonded to the recording thin film layer. A resin solution dissolved in is applied to the surface of the recording thin film layer and dried. In this way, a single-sided recording/reproducing optical disk type record carrier is obtained. It goes without saying that a double-sided recording/reproducing optical disk type record carrier can be obtained by bonding recording thin film layers made of a low tellurium oxide together with a suitable adhesive.

Effects of the Invention As is clear from the above explanation, the optical disk type record carrier for recording and reproducing of the present invention does not retain the cured resin even if the operation is repeated in the manufacturing process of forming guide grooves with an ultraviolet curable resin. Since the stamper does not adhere to the stamper, it is possible to eliminate manufacturing troubles and further reduce the occurrence of dropouts in the finished disc. Moreover, UV curable resin has the ability to give a cured product with almost no change in elastic modulus at 100c or less.
It is possible to solve the problem that the cured resin forming the guide groove changes the shape of the guide groove due to heat. In addition, the base material is a cast plate of methacrylic resin, which has almost no optical distortion, and the guide grooves are formed using liquid ultraviolet curable resin at around room temperature without applying large pressure, so optical distortion is almost eliminated. A very fine guide groove can be formed easily. Moreover, since the ultraviolet curable resin composition is in a liquid state before curing, it can be clarified by pressure filtration before use, and the optical disk type record carrier for recording and reproduction obtained in this way is made of ultraviolet curable resin. It is of high quality and takes full advantage of its features.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an optical disk type record carrier for recording and reproducing according to the present invention, and FIG. 2 is a diagram showing one method of manufacturing the optical disk type record carrier for recording and reproducing according to the present invention. 1... Resin base material, 2... Resin protective layer,
3... Ultraviolet curing resin layer, 4... Recording thin film layer, 5... Stamper 16...
Spacer, 7...Mercury rank, 8...
・Ultraviolet light.

Claims (1)

[Scope of Claims] 0) An ultraviolet curable resin layer having spiral or concentric guide grooves on one side of an optically transparent and homogeneous resin base material, and a change in optical state due to laser beam irradiation. A recording thin film layer and a resin protective layer are sequentially laminated, and the ultraviolet ray curable resin layer is composed of a polyfunctional oligoester acrylate and a monofunctional acrylate (I) represented by the following structural formula.
(However, n: 1 to 3) (2) The polyfunctional oligoester acrylate contains at least three of polyhydric alcohol, polycarboxylic acid, and acrylic acid. The optical disk type record carrier for recording and reproduction according to claim 1, which is a reaction product obtained by esterifying a seed compound. (3) The optical disk type record carrier for recording and reproduction according to claim 1, wherein a polymethacrylate resin is used as the optically transparent and homogeneous resin base material. (4) The optical disc-type record carrier for recording and reproduction according to claim 1, characterized in that the optically transparent and homogeneous resin base material is a polycarbonate resin. Claim 1, wherein the recording thin film whose optical state changes is formed of a substance containing a low tellurium oxide Te0x (0(x(2)) as a main component. Optical disk type record carrier for recording and reproduction. (6) Prepare two laminates consisting of a transparent plate, an ultraviolet curable resin layer, and a recording thin film layer, and paste the recording thin film layers of these two laminates together. An optical disc-type record carrier for recording and reproducing according to claim 1, 2, 3, 4, or 6, characterized in that the optical disk type record carrier is configured as follows.