JPH04258825A - Tight sticking type optical information recording medium - Google Patents

Abstract

PURPOSE:To provide the tight sticking type optical information recording medium which lessens generation of errors and has high reliability. CONSTITUTION:Laminate reinforcing films 7 continuing from the inner peripheral parts to the surfaces and outer peripheral parts of plural layers of thin-film laminates 6 including the recording films formed on transparent substrates 1 are formed and the ends of the inner peripheral parts 7a and outer peripheral parts 7b of the laminate reinforcing films 7 are directly joined onto the transparent substrates 1. Hot melt type adhesive layers 14 continuing from the inner peripheral parts 7a to the surfaces and outer peripheral parts 7b of these laminate reinforcing films 7 are formed and the ends of the inner peripheral parts 14a and outer peripheral parts 14b of the adhesive layers 14 are directly joined onto the transparent substrates 1.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to optical information recording media such as optical disks or opto-magnetic disks, and in particular, the present invention relates to optical information recording media such as optical disks or opto-magnetic disks, and more particularly to optical information recording media in which a plurality of thin films including a recording film are laminated on a transparent substrate. This is related to the combination type.

0002

[Prior Art] Conventionally, two optical disks having a structure in which, for example, a first enhancement film, a recording film, a second enhancement film, a reflection film, etc. are sequentially laminated on a transparent substrate are pasted together via an adhesive layer. It has been known. As the adhesive, for example, an epoxy adhesive or a solvent adhesive is used. However, in the case of the above-mentioned epoxy adhesive, it hardens on its own over time, and not only is it impossible to control the curing time, but it also takes a long time to harden at room temperature, resulting in poor workability. There are problems such as air bubbles being drawn into the layer and corrosion of the metal reflective film. On the other hand, in the case of the above-mentioned solvent-based adhesive, the reflective film may partially peel off due to the solvent seeping in, the disc may swell due to the resin material absorbing the solvent and swell, or the liquid may reach areas other than the adhesive area. Since adhesive flows around the adhesive, various problems occur in areas where adhesive is not needed. It also has disadvantages such as poor working environment. In order to overcome these drawbacks, it has recently been proposed to use hot melt adhesives. By using this adhesive, defects such as corrosion of the reflective film, swelling of the disk, and wrinkles were eliminated, and the working environment was also improved.

0003

11 to 13 are cross-sectional views of a disk veneer before hot-melt adhesive is applied. In these figures, 1 is a transparent substrate, 2 is a first enhancement film, 3 is a recording film, 4 is a second enhancement film, 5 is a reflective film, 25 is a protective film, and 26 is a dye film. By the way, hot-melt adhesives are heated and melted to liquefy, and when applying this molten slime with a brush, spatula, roller, etc., the application must be performed while the adhesive has not solidified and maintains an appropriate viscosity. must be completed. However, the melt viscosity of hot melt adhesive is 60,000.
When roller coating is performed using a material with a temperature higher than cps/120°C, if the reflective film 5 is exposed as shown in FIG. Peeling or loosening occurs between the film 3 and the enhancement films 2 and 4, resulting in a defective product. Further, even if the protective film 25 was formed only on the reflective film 5 as shown in FIG. 12, the above-mentioned problems were hardly solved. Therefore, in order to lower the viscosity of the hot melt adhesive, the temperature was set to 16, for example.
If the temperature is raised to about 0.degree. C., the transparent substrate 1 made of polycarbonate will suffer from retardation and thermal deformation due to the heat, resulting in deterioration of the optical characteristics of the transparent substrate 1. Further, the protective film 25 made of resin also undergoes thermal deformation and partial thermal decomposition. In particular, as shown in FIG. 13, in the case where a dye film 26 made of an organic compound is used, the influence of the melting temperature and melt viscosity of the hot melt adhesive is extremely large. Not only does peeling occur between the pigment film 26 and the dye film 26,
This causes thermal deformation and thermal decomposition of the pigment film 26. On the other hand, when applying hot melt adhesive with a heated roller,
If the melt viscosity is less than 60,000 cps/(120° C.), the viscosity is too low and it becomes difficult to apply to a uniform thickness. That is, if the viscosity of the hot melt adhesive is too low, it will sag and wrap around when applied, making it difficult to obtain the desired thickness, and additional work such as wiping will be required, reducing workability. In addition, hot-melt adhesives made of water-absorbing materials absorb moisture in the atmosphere and swell, so that the thickness of the bonded optical disk becomes thicker than a predetermined value. Furthermore, corrosion of each laminated film due to moisture absorption,
Problems include the progress of swelling, which has an adverse effect, leading to a decline in product quality. An object of the present invention is to eliminate such drawbacks of the prior art, and to provide a closely bonded optical information recording medium that is less likely to cause errors and has high reliability.

0004

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for bonding together an optical information recording medium in which a plurality of thin films including a recording film are laminated on a transparent substrate and a laminating member. In the laminated optical information recording medium, a laminate reinforcing film is formed that is continuous from the inner periphery to the surface and outer periphery of the thin film laminate formed on the transparent substrate,
The inner and outer peripheral ends of the laminate reinforcing film are directly bonded onto the transparent substrate. Next, a continuous hot-melt adhesive layer is formed from the inner periphery to the surface and outer periphery of the laminate reinforcing film, and the ends of the inner periphery and outer periphery of the adhesive layer are directly bonded to the transparent substrate. It is characterized by being seshime. Further, the two optical information recording media produced as described above are pasted together with their respective hot-melt adhesive layer forming surfaces facing each other in the same rotation and tracking axis, thereby achieving optical information recording using a double-sided recording method. It is characterized by creating a medium.

[0005]

[Operation] As described above, in the present invention, a continuous laminate reinforcing film is formed from the inner periphery to the surface and outer periphery of the thin film laminate formed on a transparent substrate, thereby reinforcing the thin film laminate. Therefore, the layers of the thin film laminate will not be partially peeled off even by external force when forming the hot melt adhesive layer. In particular, by limiting the melt viscosity to about 120° C., thermal decomposition and thermal deformation of the laminated film material can be prevented. Therefore, it is possible to provide a highly reliable optical information recording medium free from errors in signal writing and reading.

[0006]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a close bonding type optical disk according to an embodiment, FIG. 2 is an enlarged sectional view of the main part of the optical disk, and FIGS. 3 to 5 are for explaining the manufacturing process of the close bonding type optical disk. Figure 3 is a cross-sectional view showing the process of applying hot melt adhesive onto a single disk plate, and Figure 4 is a cross-sectional view showing the process of applying hot melt adhesive on a single disk.
FIG. 5 is a cross-sectional view showing the step of irradiating the formed hot-melt adhesive layer with ultraviolet rays, and FIG. 5 is a cross-sectional view showing the step of bonding two disk veneers together. First, the structure of a closely bonded optical disk will be explained using FIGS. 1 and 2. Using a nickel stamper having fine irregularities in which pre-pits and pre-grooves are reversed, the transparent substrate 1 is uniformly pressed through the uncured ultraviolet curable resin film. After the ultraviolet rays are irradiated from the transparent substrate 1 to cure the ultraviolet curable resin film, it is peeled off from the stamper to create a transparent substrate 1 on which the preformat has been transferred. Next, as shown in FIG. 2, a first enhancement film 2, a recording film 3, a second enhancement film 4, and a metal reflective film 5 are sequentially formed and laminated on the transparent substrate 1 using a predetermined film forming technique. In FIG. 1 and FIGS. 3 to 5, in order to simplify the drawings, the laminate 6 having a four-layer structure consisting of the first enhancement film 2, recording film 3, second enhancement film 4, and metal reflective film 5 is shown with the same hatching. It is shown in As the transparent substrate 1, optically transparent materials such as glass, polycarbonate, polyacrylate, polymethyl methacrylate, polymethylpentene, and epoxy are used. As the first enhancement film 2 and the second enhancement film 4, a dielectric material such as silicon nitride or aluminum nitride is used. As the recording film 3 made of an optical-magnetic recording material, for example, T
b-Fe alloy, Tb-Fe-Co alloy, Gd-Tb-F
e-Nb alloy, Gd-Tb-Co-Fe-Nb alloy, G
d-Tb-Fe alloy, Dy-Fe alloy, Mn-Cu-B
i alloy (crystalline), Gd-Tb-Fe-Ge alloy, Ge
-Co alloy, Gd-Tb-Co alloy, Gd-Tb-Co
-Nb alloy, mixture of Tb-Fe alloy and Gd-Fe alloy, mixture of Tb-Fe alloy and Gd-Fe-Co alloy, Tb-Dy-Fe-Co alloy, Tb-Ni-Fe alloy, Dy- Fe-Gd-Co alloy, Pt-Co alloy, Ni
-Cr alloys and other amorphous alloys are mainly used. Examples of recording materials for write-once optical information recording media include Te, Te-Se-Pb alloy, Te-C alloy, Te-T
eO-TeO2 alloy, Ag-Sn alloy, Au-Sn alloy, etc. are used. Examples of the metal reflective film 5 include Al, Al-Ni alloy, Al-Ti alloy, Al-Cr
alloy, Al-Mn alloy, Al-Ni-Ti alloy, etc. are used. As shown in FIG. 1, a continuous laminate reinforcing film 7 is formed from the inner periphery to the surface and outer periphery of the laminate 6 having a four-layer structure. This laminate reinforcing film 7 is formed of, for example, an ultraviolet curable resin as shown below, and the method for forming the film includes, for example, a spinner coating method. In addition, the outer peripheral part 7b is thicker than the surface part 7c, and the ends of the inner peripheral part 7a and the outer peripheral part 7b are directly bonded (adhered) onto the transparent substrate 1. ■． An ultraviolet curing resin whose main component is a polymer of modified acrylate modified with polyurethane, epoxy, polyester, etc. and acrylic ester (for example, methyl acrylate, ethyl acrylate, n-butyl acrylate). (Specific examples) ○ Polyisobutylene or isoprene-isobutylene copolymer 100 parts by weight ○ Difunctional or trifunctional acrylic monomer or oligomer (dicyclopentadienyl diacrylate, trimethylolpropane trimethacrylate, 1,10 decanediol) dimethacrylate) 40-100
Part by weight ○ Acrylic monomer with 1 functional group (isobornyl acrylate, C12-C18 acrylic acrylate)
60-100 parts by weight ○Photopolymerization agent (benzoyl peroxide)
2 to 5 parts by weight ■. A rubber non-reactive resin dispersed in the ultraviolet curable resin. (Specific example) ○ Oligomer in which both ends of polybutadiene are modified with acrylic or methacrylic

100 parts by weight ○Bifunctional acrylic monomer (hydrogenated dicyclopentadienyl diacrylate)

100
Part by weight ○Acrylic monomer with one functional group (isobornyl acrylate, lauryl acrylate, tridecyl acrylate)
40-80 parts by weight ○Photopolymerization agent (benzoyl peroxide)
3 to 10 parts by weight ■. A rubber non-reactive resin and inorganic fine powder surface-treated with a photocurable coupling agent are dispersed in the ultraviolet curable resin. (Specific example) ○Oligomer with acrylic or methacrylic modified silicone rubber at both ends

100 parts by weight ○Bifunctional acrylic monomer (hydrogenated dicyclopentadienyl diacrylate)

100 parts by weight ○Trifunctional acrylic monomer (trimethylolpropane trimethacrylate)

40-80 parts by weight ○ Acrylic monomer with one functional group (isobornyl acrylate, lauryl acrylate, tridecyl acrylate)
40-80 parts by weight ○Photopolymerization agent (benzoyl peroxide)
3 to 10 parts by weight ○ Carbon black treated with γ-methacryloxypropyltrimethoxysilane


A little ■． ○ An organic compound that has an acrylic group or methacrylic group at the end and a polybutadiene skeleton or poly-1-butene skeleton in the molecule; ○ An organic compound that has one acrylic group or methacrylic group in one molecule and Organic compounds that do not have polar groups such as hydroxyl, carboxyl, thiol, or amine groups (methyl acrylate, methyl methacrylate, etc.) and ○ have two acrylic or methacryl groups in one molecule. A combination of organic compounds that do not have polar groups such as hydroxyl, carboxyl, thiol, or amine groups (ethyl glycol acrylate, ethyl glycol methacrylate, etc.) and photopolymerization agents (benzyls, anthraquinones, etc.). In this embodiment, an ultraviolet curable resin was used as the laminate reinforcing film 7, but the present invention is not limited thereto, and other photocurable resins such as electron beam curable resins may also be used.

In this way, a continuous laminate reinforcing film 7 is formed from the inner periphery to the surface and outer periphery of the thin film laminate 6, and the inner periphery 7a and outer periphery 7b of the laminate reinforcing film 7 are thickened. Then, by bonding (adhering) the ends of the inner peripheral part 7a and the outer peripheral part 7b directly onto the transparent substrate 1, the thin film laminate 6 is formed into an optical disk firmly reinforced by the reinforcing film 7. A veneer is obtained. In particular, if the photocurable or ultraviolet curable resin that is the resin material for the laminate reinforcing film 7 is brought into direct contact with the transparent substrate 1 containing polyacrylate or polymethacrylate and irradiated with ultraviolet rays, the laminate reinforcing film 7 will be When cured, a chemical bond is formed between the laminate reinforcing film 7 and the transparent substrate 1, so that the adhesive force between the laminate reinforcing film 7 and the transparent substrate 1 can be further strengthened. As shown in FIG. 1, the laminate reinforcing film 7 of the transparent substrate 1
A hub 9 having a through hole 8 is bonded in advance to the center position of the surface opposite to the surface on which the holes 8 and the like are formed.

The transparent substrate 1 to which the hub 9 is fixed is placed on a tray 10 with the laminate reinforcing film 7 facing upward, as shown in FIG. 3, and sent to the next step of applying hot melt adhesive. . Application roller 12 equipped with a hopper 11 at the top
and a feed roller 13 arranged to face the application roller 12. and the hopper 11
A hot-melt adhesive 14, which will be described later, is housed in a molten state. A predetermined contact pressure is applied between the laminate reinforcing film 7 of the optical disk single plate placed on the tray 10 and the adhesive application roller 12, and as shown in the figure, the optical disk single plate is The tray 10 on which the body is placed is moved to the coating roller 1.
The application roller 12 rotates the molten hot melt adhesive 14 by passing it between the application roller 12 and the feed roller 13.
The film is sequentially extracted from the lower part of the hopper 11 by the hopper 11 and applied onto the laminate reinforcing film 7. Inner peripheral portion 7 of laminate reinforcing membrane 7
A part of the molten hot-melt adhesive 14 applied to the top of the outer circumferential portion 7a and the outer circumferential portion 7b drips down, and the surface portion 1
An inner circumferential portion 14a and an outer circumferential portion 14b are formed which are thicker than the inner circumferential portion 4c. The ends of the inner circumferential portion 14a and the outer circumferential portion 14b are directly adhered (joined) onto the transparent substrate 1 while being cured.

Next, a preferred example of the hot melt adhesive 14 will be explained. ■． Adhesive at room temperature, melt viscosity 60-13
A hot melt adhesive having an adhesive strength of 700,000 cps or less at 0°C and a 180 degree peel strength of 4 kg per inch at 95°C or less. A hot melt adhesive having such physical properties is, for example, one in which an ethylene-vinyl acetate copolymer is used as a base polymer, and appropriate amounts of a tackifying agent and a curing agent are blended therein. Examples of the tackifier include natural resins or modified products such as rosin, polymerized rosin, hydrogenated rosin, and rosin ester, aliphatic, alicyclic, aromatic, petroleum resins, terpene resins, terpene-phenol resins, and chroman resins. Resin etc. are used. Examples of the softening agent include process oil, paraffin oil,
Castor oil, polyptene, low molecular weight polyisobutylene, etc. are used. ■． 100 to 600 parts by weight of a sticking agent and 100 parts by weight or less of a curing agent are blended with 100 parts by weight of a base polymer whose main component is a block-shaped thermoplastic elastomer. And the softening point is 140℃ or less, 20℃
The tensile adhesive strength at 1 kg/cm2 or more is 1 kg/cm2 or more, and the melt viscosity at 160°C is 1000 P or less. As the base polymer, A-B, A-B-A, B-
A-B (in the formula, A is a polystyrene polymer block with a molecular weight of 2000 to 12,500, B is a molecular weight of 1000 to 25
000 polybutadiene or polyisobutylene or an ethylene-butylene copolymer), or a mixture of two or more thereof, or a mixture thereof with other synthetic rubber or polyolefin polymer is used. As the adhesion promoter and softener, ■
The same one as mentioned above is used. ■． An ultraviolet crosslinkable hot melt adhesive, in particular, a base polymer, a saturated hydrocarbon resin oligomer having at least one acryloyl group in one molecule as an ultraviolet crosslinkable component, and a photopolymerization initiator in a predetermined amount. Hot melt adhesive. As the base polymer, a base polymer similar to that shown in (1) is used, and appropriate amounts of a tackifying agent and a curing agent are blended therein. Examples of the saturated hydrocarbon resin oligomer having at least one acryloyl group in one molecule include saturated hydrocarbon resin oligomers containing at least one hydroxyl group or carboxyl group in one molecule (hydrogenated polybutadiene, polybutene, etc.). , hydrogenated polyisobrene, polyisobutylene, etc.), phrethane acrylate, epoxy acrylate, ester acrylate, etc., or a mixture of two or more thereof is used. This oligomer is added in an amount of 5 to 100 parts by weight based on 100 parts by weight of the base polymer. As the photopolymerization initiator, for example, the following ones are used that generate radicals when irradiated with ultraviolet rays, and the addition rate thereof is 0.5 to 5 % to the total of the base polymer and the ultraviolet crosslinkable component. Weight%. ○Benzoin ether compounds such as benzoin isopropyl ether and benzoin isobutyl ether. ○Benzophenone, p-methoxybenzophenone, p-
Benzophenone compounds such as promobenzophenone. ○ Thioxanthone compounds such as benzyl methyl ketal, 2,2-diethoxyacetophenone, and 1,1-dichlorothioxanthone. Specific formulation examples of this ultraviolet crosslinkable hot melt adhesive are as follows. ○Polystyrene-ethylene-butylene copolymer block thermoplastic elastomer

2
0 parts by weight ○ Hydrogenated polybutadiene oligomer containing acryloyl groups at both ends (urethane acrylate type)

25 parts by weight ○Hydrogenated styrene tackifier

40 parts by weight ○Polyisobutylene

10 parts by weight ○Benzyl methyl ketanol
3 parts by weight In the embodiment shown in the drawings, an ultraviolet cross-linkable hot melt adhesive is used.After applying the hot melt adhesive 14 as shown in FIG.
Irradiate with ultraviolet light of 9 W·S/cm2 (see Figure 4). The physical properties of this adhesive layer are as follows. ○ Melt viscosity: 72000cps (12
0°C) ○Heat-resistant creep property: No abnormality (weight 200g, temperature 80°C, load time 24 hours) ○Heat-resistant moisture adhesion: No peeling (Putschia Kutsker measuring device specified in JIS,
Temperature: 100°C, relative humidity: 100%) ○Water absorption: 0.10% or less Especially for optical discs using transparent substrates containing acrylate groups or methacrylate groups, adhesion between ultraviolet crosslinkable hot melt adhesives and transparent substrates It is characterized by the ability to form particularly strong adhesion with chemical bonds at the adhesive portion and the UV-curable laminate reinforcing film.

As shown in FIG. 10, the inner peripheral part 7a (t1), the outer peripheral part 7b (t2), and the surface part 7c of the laminate reinforcing membrane 7
(t3) and the inner circumference 1 of the hot melt adhesive 14
4a (t4), outer peripheral part 14b (t5), surface part (t6)
An example of the thickness of 14c is as follows. t1 = 2 to 300 μm t2 = 2 to 300 μm t3 = 2 to 6 μm t4 = 30 to 400 μm t5 = 30 to 400 μm t6 = 20 to 40 μm

Next, as shown in FIG. 5, the two disk veneers are stacked on the assembly jig 15 so that the hot melt adhesive 14 is bonded to each other, and the disks are bonded together.
Paste together with a pressure of 0 kg/cm2. A reference pin 16 is erected in the center of this assembly jig 15, and when two single disk plates are stacked together, by passing this reference pin 16 through the through hole in the hub 9 of the single disk plate, the two The two disk veneers can be pasted together with high precision. In this way, a double-sided recording type optical disc as shown in FIG. 1 can be manufactured. As shown in the figure, chamfered or rounded notches 17 are formed in advance on the inner and outer edges of the transparent substrate 1 to prevent the hot melt adhesive 14 from extruding. In order to prevent the hot-melt adhesive 14 from overflowing and adhering to the center reference pin 16 of 15, the cutout 17 functions as a reservoir for the overflowing adhesive.

FIG. 6 is a diagram showing a second embodiment of the present invention. The difference between this embodiment and the first embodiment shown in FIG. 2 is as follows.
An adhesive reinforcing film 18 made of silicon dioxide, for example, is formed between the transparent substrate 1 and the first enhancement film 2.

FIG. 7 is a diagram showing a third embodiment of the present invention. In the case of this embodiment, a light absorbing/thermal converting film 19 is formed on a transparent substrate 1 on which prepits and pregrooves are formed, and a metal film (recording/reflecting film) 20 is formed thereon. The light-absorbing heat conversion film 19 may be made of organic dyes such as cyanine dyes, polymethine dyes, anthraquinone dyes, triphenylmethane dyes, phthalocyanine dyes, pyrylium dyes, azulene dyes, and metal-containing azo dyes. dyes are used. Further, as the metal film (recording/reflection film) 20, for example, Al, Au, Al-T
Metals such as i-alloys are used. Although not shown, Figure 7
The metal film (recording-reflection film) 20 has the same light-reflecting function as the metal film (recording-reflection film) 20 in
Light absorption-thermal conversion film 19 that absorbs 0 to 40% and converts it into heat
A metal film with light absorbing property, heat generating property, and light reflecting property, which also has the functions of
In the optical disk used instead of the laminated film of 9 and the metal film 20, materials such as Ag-Sn alloy, Au-Sn alloy, etc. are used as the metal film having light-absorbing, heat-generating, and light-reflecting properties. used.

FIG. 8 is a diagram showing a fourth embodiment of the present invention. This embodiment is different from the third embodiment shown in FIG. 7 in that a heat conductive film 21 is formed between a light absorbing/thermal conversion film 19 and a metal film (recording/reflection film) 20. The thermally conductive film 21 is made of, for example, Si3N4, SiO
2, Al2O3, etc. are used.

FIG. 9 is a diagram showing a fifth embodiment of the present invention. This embodiment differs from the first embodiment shown in FIG. A recess 22 is formed. As shown in the figure, the hot melt adhesive 14 is not applied to the recess 22. In the case of an optical disk having an area not coated with the hot melt adhesive 14 in this way, the hub 9 can be bonded to the transparent substrate 1 using a photocuring adhesive. Retrofitting (a method of attaching the hub after the optical disk is completed) is now possible.

The hot-melt adhesive used in the present invention, particularly the hot-melt adhesive applied to the manufacturing method in which it is applied to an optical disk by a hot roller, has a viscosity at 120°C (as measured by a B-type viscometer specified in JIS). measurement) is in the range of 60,000 to 110,000 cps, preferably in the range of 70,000 to 90,000 cps. If the viscosity is lower than 60,000 cps, an adhesive layer with a predetermined thickness and shape cannot be obtained, and the adhesive drips and adheres to the surrounding area, which requires wiping off. On the other hand, if the viscosity is higher than 110,000 cps, good transfer (coating) to the disk veneer cannot be achieved during roller coating, etc., and there is a risk that loosening may occur between the layers of the laminate. In addition, hot melt adhesives are used at temperatures of 100 to 160°C in order to avoid thermal effects on the recording film (particularly when organic dyes such as cyanine dyes are used) and reinforcing films that make up the disk single plate, and to obtain a predetermined viscosity. It is preferred to use it in a temperature range, preferably in a temperature range of 110 to 140°C. Therefore, generally in the temperature range of 110 to 140℃
0000-110000cps, especially 70000-90
The most preferred hot melt adhesive is a hot melt adhesive material that can be manufactured at 0.000 cps. Furthermore, the water absorption rate of hot melt adhesives must be regulated to 0.10% or less in order to eliminate the adverse effects of atmospheric moisture absorption. As in the above example, when a hot melt adhesive that is sticky at room temperature is heated and melted into a viscous state and used by roller application, the viscosity of the hot melt adhesive is not a liquid flow state, and the viscosity is not like that of a liquid, and when the roller application is performed, the lamination layer is formed. Peeling in each membrane of the body,
It does not cause loosening or damage, can be roller coated, has good adhesive properties, and provides a stable bonding effect. Furthermore, as in the above embodiment, if both the laminate reinforcing film and the hot melt adhesive layer are made of a material containing an acrylic organic compound as a main component, the laminate reinforcing film and the hot melt adhesive layer can be bonded together by ultraviolet irradiation. The adhesion (adhesion) between the two becomes better. In the above embodiment, a case has been described in which single disk plates each having a recording film or the like are bonded together, but the present invention is not limited to this, and the present invention is not limited to this, and the present invention does not include a single disk plate having a recording film or the like and a single disk plate having a recording film or the like. The present invention can also be applied to a so-called single-sided recording type optical information recording medium in which a plate-like body (which serves as a bonding member in place of a single disk) is bonded together.

[0017]

Effects of the Invention The following table shows changes over time in the mechanical properties of the closely bonded optical disk obtained in the first example. Note that the test conditions were 80° C. and 90% RH.
Table Test time Vertical runout change (μm) Tilt angle change (
mrad) Inner circumference
Center part Outer part Inner part
Center part Early part of outer periphery 20
55 95
0.5 0.5 1.0
100 hours 25 50
87 1.0 0.7
0.7 200 hours 32
58 75 1.
0 1.0 0.5 As is clear from this table, even when tested in a harsh environment of high temperature and humidity, the close-contact type optical disk according to the example of the present invention has a high resistance to vertical vibration and to the horizontal surface of the disk. It can be seen that the change in the tilt angle is extremely small. This means that there are fewer errors when writing or reading signals. As described above, in the present invention, a continuous laminate reinforcing film is formed from the inner periphery to the surface and outer periphery of the thin film laminate formed on a transparent substrate to reinforce the thin film laminate. The layers of the thin film laminate will not peel off even due to external force when forming the mold adhesive layer. Therefore, it is possible to provide a highly reliable optical information recording medium free from errors in signal writing and reading.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a closely bonded optical disk according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the optical disk.

FIG. 3 is a cross-sectional view showing a process of applying a hot melt adhesive onto a single disk of the optical disk.

FIG. 4 is a cross-sectional view showing a step of irradiating ultraviolet rays to the hot melt adhesive layer coated and formed on the disk single plate.

FIG. 5 is a cross-sectional view showing the process of bonding two disk veneers together.

FIG. 6 is a sectional view of a main part of a closely bonded optical disc according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a main part of a closely bonded optical disk according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a closely bonded optical disc according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a closely bonded optical disk according to a fifth embodiment of the present invention.

FIG. 10 is an explanatory diagram showing dimensions of main parts of a single disk plate according to an embodiment of the present invention.

FIG. 11 is a sectional view of a single disk plate of Conventional Example 1.

FIG. 12 is a cross-sectional view of a single disk plate of Conventional Example 2.

FIG. 13 is a cross-sectional view of a single disk plate of Conventional Example 2.

[Explanation of symbols]

1 Transparent substrate 2 First enhancement film 3 Recording film 4 Second enhancement film 5 Metal reflective film 6 Laminated body 7 Laminate reinforcement membrane 7a Inner circumference 7b Outer periphery 14 Hot melt adhesive 14a Inner circumference 14b Outer periphery 18 Adhesive reinforcing film 19 Light absorption-thermal conversion film 20 Metal film 21 Thermal conductive film

Claims (13)

[Claims] 1. A close-contact lamination type optical information recording medium in which an optical information recording medium in which a plurality of thin films including a recording film are laminated on a transparent substrate and a laminating member are laminated together,
A continuous laminate reinforcing film is formed from the inner periphery to the surface and outer periphery of the thin film laminate formed on the transparent substrate, and the ends of the inner periphery and outer periphery of the laminate reinforcing film are directly transparent. Bonded onto a substrate, a continuous hot melt adhesive layer is formed from the inner periphery to the surface and outer periphery of the laminate reinforcing film, and the edges of the inner periphery and outer periphery of the adhesive layer are directly transparent. A closely bonded optical information recording medium characterized by being bonded onto a substrate. 2. The closely bonded optical information recording medium according to claim 1, wherein the inner and outer peripheral portions of the laminate reinforcing film are thick. 3. The close-contact lamination type optical information according to claim 1 and claim 2, characterized in that the inner circumferential portion and the outer circumferential portion of the hot-melt adhesive layer are formed thickly. recoding media. 4. A close-contact type optical information recording medium according to claim 1, wherein the hot-melt adhesive is a hot-melt adhesive that is sticky at room temperature. 5. A closely laminated optical information recording medium according to claim 1, wherein the hot melt adhesive is an ultraviolet crosslinkable hot melt adhesive. 6. The closely bonded optical information recording medium according to claim 1, wherein the laminate reinforcing film and the hot melt adhesive are made of a material containing an acrylic organic compound as a main component. . 7. A close bonding type according to claim 1, wherein the thin film laminate is composed of a first enhancement film, a recording film, a second enhancement film, and a reflective film. Optical information recording medium. 8. The thin film laminate according to claim 1, wherein the thin film laminate includes an adhesive reinforcement film, a first enhancement film, a recording film,
A closely bonded optical information recording medium comprising a second enhancement film and a reflective film. 9. The closely bonded optical information recording medium according to claim 1, wherein the thin film laminate is composed of a light absorbing-thermal conversion film and a metal film. 10. A closely bonded optical information recording medium according to claim 1, wherein the thin film laminate is composed of a light-absorbing heat-transfer film and a metal film. 11. The closely bonded optical information recording device according to claim 1, wherein the thin film laminate is composed of a metal film having light absorbing properties, heat generating properties, and light reflecting properties. Medium. 12. In claim 1, the laminate reinforcing film and the hot melt adhesive layer are both made of an ultraviolet curable material, and the interface between the laminate reinforcing film and the hot melt adhesive layer has no chemical bond. A closely bonded optical information recording medium characterized by being bonded together. 13. In claim 1, the hot melt adhesive has a hot melt viscosity of 600 at 120°C.
00 to 110,000 cps and a moisture absorption rate of atmospheric moisture of 0.10% or less.