JPH03189940A - Manufacture of optical disk - Google Patents

Abstract

PURPOSE:To reduce the generation of defective disks by forming an antistatic layer on a hard coating layer and thereafter adhering two substrates forming a forming recording layer part on a side where grooves or pits of a substrate are successively formed. CONSTITUTION:Antistatic layers 16, 17 are formed on hard coating layers 14, 15 formed on a side where grooves or pits of substrates 1, 8, are not formed. On the side where grooves or pits of substrates 1, 8 are formed, two substrates 1, 8 where the recording layer part is successively with ceramic layers 2, 9, recording layers 3, 10, ceramic layers 4, 11, reflecting layers 5, 12, and protective layers 6, 13 are adhered. In this production process, disks having defects in hard coating layers or antistatic layers are rejected after the antistatic layers 16, 17 are formed, and only good disks are sent to next stage. Thereby, defective disks due to defects in hard coating layers or antistatic layers can be rejected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an optical disc in which information is recorded, reproduced, or erased using light.

[Prior Art] In conventional optical discs, after a recording layer is formed, a hard coat layer is formed, and then the layers are bonded together.

Thereafter, an antistatic layer is formed by a spray method or a spin code method.

[Problem to be solved by the invention] However, the conventional technology had the following problems.

If a hard coating or antistatic coating is applied after forming the recording layer, hard coating defects and antistatic coating defects will occur, which will lead to defects in the disk.

The present invention is intended to solve such problems, and its objectives are as follows. Even if a hard coat defect or an antistatic coating defect occurs, the disk is considered defective.

Since no recording layer or the like is formed, the disc is less likely to be defective.

[Means for Solving the Problems] In the optical disc of the present invention, tracking grooves or pits are formed on one side of a substrate, and then a hard coat made of a photocurable resin is applied to the side of the substrate where the grooves or pits are not formed. an antistatic layer is formed on the hard coat layer, and then a ceramic layer is formed on the side of the substrate on which the groove or bit is formed.
storage layer, recording layer, ceramic layer 1 reflective layer.

The substrate on which the protective layer and the recording layer part were sequentially formed was 2
It is characterized by using two sheets and pasting them together.

In the present invention, the adhesive includes at least an epoxy base resin and a curing agent 1, a mixture of an ultraviolet curable resin base resin and a curing agent to which an organic peroxide is added, or an epoxy group (
Compounds having meth)acryloyl groups 1 For example, bisphenol A, bisphenol F type, phenol novolac type, cresol/borac type epoxy moiety (meth)
It is preferable to use an acryloyl-modified compound to which a photopolymerization initiator, an epoxy curing agent, and, if necessary, an organic oxide are added. In these adhesives, the ratio of the total amount of epoxy groups to the total amount of meth)acryloyl groups is 95 to 60% of epoxy groups, and 5 to 40% of (meth)acryloyl groups.
%. I hope (is an epoxy group 9
o to 80%, (meth)acryloyl group 10 to 20
% is appropriate.

Examples of epoxy base agents include bisphenol- For A series, bisphenol F series, novolac series, etc.

or by adding a reactive diluent, which is a low viscosity epoxy.

It is better to use one without adding it. When the content of the reactive diluent increases, the viscosity of the adhesive decreases and workability improves, but the heat resistance of the adhesive layer decreases.

It is better to limit the amount of addition as it will reduce the reactivity and deteriorate the properties of the adhesive layer.

Epoxy curing agents include acid anhydrides, aromatic amines, aliphatic amines, amides, etc. Among them, it is best to use one with a pot life of 1 to 50 hours at room temperature.
It is advisable to select a curing agent that can be cured at temperatures between °C and 80 °C. Examples include imidazoles such as 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-inbutyl-2methylimidazole, and cycloaliphatic amines such as menthanediamine.

As the main ingredient of the UV-curable resin, it is best to use one with relatively low viscosity at room temperature and one with high reactivity. Examples include 1,6-hexanediol diacrylate, trimethylolpropane=4 triacrylate. , neopentyl glycol diacrylate, dipentaerythritol hexaacrylate,
Since tripropylene glycol diacrylate and the like are available, it is recommended to use these as the main ingredients.

As an example of the curing agent for the ultraviolet curable resin, one that absorbs at wavelengths longer than 300 nm is used. Examples include benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, benzoin, benzone ethyl ether, benzoin isobutyl ether, 1- (4-isopropylphenyl) -2
-1=droxy-2-methylpropan-1-one, 2hydroxy-2-methyl-1-phenylpropan-1-one, 3,3-dimethyl-4-methoxybenzophenone, and the like.

In the present invention, the temperature at the time of bonding needs to be changed depending on the viscosity of the adhesive, and is preferably higher than room temperature, but is preferably 70° C. or lower in order to make it easier to obtain a constant constant temperature. More preferably from 40°C to 6
It is 0°C. The substrate heating for curing the adhesive is preferably from 40°C to 80°C, depending on the curing temperature of the adhesive. More preferably it is 50°C to 70°C.

In the present invention, as for the mixing ratio of epoxy and ultraviolet curing resin, the higher the mixing ratio of epoxy resin, the better the properties as an adhesive, and the ratio of epoxy and ultraviolet curing resin is 95% by weight.
: 5 to 70: ao is preferred. Here, epoxy refers to an epoxy main ingredient and a curing agent, and an ultraviolet curable resin refers to an ultraviolet curable resin in which an organic peroxide is added to the main ingredient and a curing agent.

In the present invention, if the bonding is performed under reduced pressure, the adhesive can be easily degassed and air bubbles are difficult to be incorporated into the adhesive layer.

In the present invention, it is preferable that the time for which the disks are left to stand after being bonded together and temporarily fixed by irradiation with light is set to be longer than the time for the adhesive to naturally harden. For example, if you leave it alone for 50
In the case of bonding with an adhesive that completely loses fluidity and hardens over time, it is better to set the time to 505-6 hours or more.

[Example] The present invention will be explained in detail below based on the drawings.

FIG. 1 is a basic configuration diagram of an optical disk formed by the optical disk manufacturing method according to the present invention, in which 1 and 8 are polycarbonate substrates, 2 and 8 are 5iAIN layers, 3 and 1
0 is TbFeCoN, 4 and 11 are SiAI N layers,
5 and 12 are A1 layers, 6 and 13 are protective layers, 7 is an adhesive layer, 14 and 15 are hard coat layers, and 16 and 17 are antistatic layers.

The polycarbonate substrates of Nos. 1 and 8 were formed by injection compression molding. After forming hard coat layers 14 and 15, antistatic coat layers 16 and 17 were formed. Therefore, those with hard coat defects or antistatic coating defects were removed and the process proceeded to the next step. 2 and 9 of 5
The iAIN layer was formed by RF reaction magmaftron sputtering using a mixed gas of nitrogen and argon using a sintered target of SjAl.

The NdDyFeCo layers Nos. 3 and 10 were formed by DC magnetron sputtering using an NdDyFeCo alloy target. Similar to the 5iAIN layers 2 and 9, the 5iAIN layers Nos. 4 and 11 were formed by the RFF magnetron sputtering method by introducing a mixed gas of nitrogen and argon. 5 and 12 A
The first layer was formed by DC magnetron sputtering using an A1 target and introducing argon gas.

The adhesive layer in No. 7 is Epicron S-1 from Dainippon Ink and Chemicals.
29 and oil-based shell epoxy Ebicure IBMI-1
After applying a mixture of 2 and 1,6-hesanodiol diacrylate, t-butylperoxyisobutyrate, and Irgacure 907 manufactured by Ciba Geigy in a ring shape to the side on which the recording layer was formed, vacuum Combine the bonded substrate with another substrate within the system, place the bonded substrate on a hot plate or put it in an oven to spread the adhesive, and irradiate it with ultraviolet rays using a meta-8-halide lamp or high-pressure mercury lamp. The adhesive in the area where the recording layer was not formed was temporarily cured, and then left for 72 hours to cure the adhesive layer.

then 50'C for 3 hours, 60'C for 8 hours, 80°C
The adhesive layer was cured by heating for 2 hours.

Further, since it is better to make the thickness of the adhesive layer 60μ or less from the viewpoint of weather resistance, the thickness of the adhesive layer needs to be 60μ or less. Preferably 50μ or less.

More preferably, the amount of adhesive is adjusted to 40μ or less, and the temperature is adjusted when spreading the adhesive.

Alternatively, it is better to press or the like when bonding.

The hard coat layers 14 and 15 are made of trimethylolbroban triacrylate and 1. After spin-coding 6-hexanediol diacrylate and Dolphincure 907 manufactured by Ciba Geigy on the surface of the substrate, it was cured by irradiating ultraviolet rays with a high-pressure mercury lamp.

The antistatic layers Nos. 16 and 17 were formed using Guigyu Ni-EX-801 manufactured by Dainippon Ink and Chemicals by a spin-coding method.

In addition, as the adhesive layer of No. 7, Ciba Geigy's Irgacure 907 was added to a bisphenol F-based epoxy resin in which 20% of all epoxy groups are acryloyl groups.
5%, oily shell epoxy Ebicure BMI-12
When an optical disc was prepared using 6% of γ-glycidoxypropyltrimethoxysilane and 3% of γ-glycidoxypropyltrimethoxysilane, with the other conditions unchanged from the configuration shown in Figure 1, the characteristics were almost the same as in Figure 1. We were able to create an optical disc with

According to the optical disc manufacturing method of the present invention, defects caused by hard coat defects and antistatic coating defects can be eliminated.
Disc yield increased. When a hard coat or an antistatic layer is formed after bonding, as in the past, the optical disc becomes defective due to defects that occur there.

Note that the present invention should not be considered limited to these embodiments, and that various modifications can be made without departing from the spirit of the present invention.

[Effects of the Invention (90) As described above, the optical disc manufacturing method of the present invention has the effect that the disc will not become defective due to hard coat defects or antistatic coating defects.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of an optical recording medium according to the present invention. 1.8... Polycarbonate substrate 2, 9...
・5iAIN protective layer 3, 10-.-NdDyFeCo recording layer 4, 11・
...5jAIN protective layer 5.12...A1 layer 6.13...Protective layer 7, ...Adhesive layer 14.15...Hard coat layer 16.17...Antistatic layer 11- 14, I5...Hardco

Claims (1)

[Claims] After forming tracking grooves or pits on one side of the substrate, a hard coat layer made of a photocurable resin is formed on the side of the substrate where the grooves or pits are not formed, and an antistatic layer is formed on the hard coat layer. and then, on the side of the substrate where the grooves or pits are formed, a ceramic layer, a recording layer, a ceramic layer, a reflective layer, a protective layer, and a recording layer portion are sequentially formed on the substrate. 1. A method for manufacturing an optical disc, characterized in that the optical disc is laminated using the same method.