JPH10315345A - Manufacture of optical information recording medium disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical information recording medium disc with a low bit error rate by optimizing a step to manufacture the medium disc using a substrate of a cyclic olefin resin. SOLUTION: A specified part of the surface of a substrate of a cyclic olefin resin is subjected to a corona discharge process prior to the formation of a recording coat layer. The durability of information is influenced by not only the adhesion between the substrate and a ultraviolet-curable resin coat layer but also the adhesion between the substrate and the recording coat layer or the adhesion between the recording coat layer and the ultraviolet-curable resin coat layer. To improve the durability, the corona discharge process is performed to the surface of the substrate. Thus it is possible to manufacture the optical information recording medium disc with a low bit error rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical information recording medium disk having excellent durability, and more particularly, to a music CD, CD-ROM, laser disk, CD-R, and the like having excellent durability. The present invention relates to a method for manufacturing an optical information recording medium disk such as a mini disk, MO, and DVD.

[0002]

2. Description of the Related Art Conventionally, music CDs, CD-ROMs, laser disks, CD-Rs, minidiscs, MOs and DVs have been used.
For optical information recording medium disks such as D, a substrate obtained by injection-molding a transparent thermoplastic resin has been used. As a molding material, a polycarbonate resin (P
C) and polymethyl methacrylate resin (PMMA) have been used. However, optical information recording medium disks using substrates formed of these PCs and PMMA are inferior in moisture resistance and durability, and the recording film layer is liable to deteriorate under the influence of environmental temperature and humidity. There was a problem that it could not withstand use.

Recently, the use of a cyclic olefin resin as a transparent thermoplastic resin having improved moisture resistance and durability, which is suitable for a substrate for an optical information recording medium disk, has been proposed. For example, JP-A-63-14101, JP-A-63-275654, JP-A-3-12835
And JP-A-4-161444 disclose the use of a polymer of a cyclic olefin having a norbornene ring for an optical information recording medium disk. Kaihei 7-258362
The polymer of a cyclic diene disclosed in Japanese Patent Application Publication No. H10-163, etc. is also a molding material suitable for an optical information recording medium disk because of its transparency and high moisture resistance.

[0004] However, a substrate using such a cyclic olefin resin is particularly excellent in characteristics such as moisture resistance, but a recording film layer required for an optical information recording medium disk or an ultraviolet curable resin film for protecting the recording film layer. There is a problem in the adhesiveness with the layer, for example, in the durability promotion test of high temperature and high humidity, there is a problem that the ultraviolet curable resin film layer is peeled off, the recording film layer is deteriorated, and the recording is lost. There has been a problem that it cannot withstand recent high demands for a small bit error rate.

[0005]

As described above, in the conventionally known process for manufacturing an optical information recording medium disk using a substrate made of a cyclic olefin resin, the durability is not sufficient. As a result of the test, a bit error may occur due to a minute defect even though it looks like there is no defect visually. An object of the present invention is to provide a method of manufacturing an optical information recording medium disk having a small bit error rate by optimizing a manufacturing process of an optical information recording medium disk using a substrate made of a cyclic olefin resin. is there.

[0006]

The inventors of the present invention have conducted intensive studies to improve such disadvantages of the prior art and found that the durability of information is not limited to the adhesiveness between the substrate and the ultraviolet-curable resin film layer. Surprisingly, the adhesion between the substrate and the recording film layer,
Alternatively, it was found that the adhesiveness between the recording film layer and the ultraviolet-curable resin film layer was affected, and it was effective to perform a corona discharge treatment on the substrate surface for these improvements. It was completed.

Thus, according to the present invention, a step of obtaining a substrate by injection-molding a molding material comprising a cyclic olefin resin, and then forming a recording film layer and an ultraviolet curable resin film layer as an upper layer are formed. Step of performing corona discharge treatment on the substrate surface at a portion where the recording film layer is formed, and then forming a recording film layer on the substrate surface subjected to the corona discharge treatment. Next, the boundary line between the entire recording film layer and the portion with and without the recording film layer. And forming a UV curable resin film layer so as to cover the optical information recording medium disk.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below by dividing them into items.

(Cyclic olefin resin) In the present invention, a cyclic olefin resin is used. This resin is a non-crystalline, transparent resin having a hydrocarbon ring structure in the main chain or side chain of the polymer.
264646, JP-A-64-1705, JP-A-1-168724, JP-A-1-168725
-Opening polymer of a monomer having a norbornene ring and hydrogenated product thereof disclosed in JP-A-60-1
68708 and the like, an addition polymer of a monomer having a norbornene ring and an α-olefin, JP-A-6-13657 and JP-A-7-258362.
And addition polymers of cyclic olefins and cyclic dienes and hydrogenated products thereof disclosed in Japanese Patent Application Publication No. These resins are available from Zeon Corporation under the trade name Z
EONEX, trade name AP from Mitsui Petrochemical Industry Co., Ltd.
It is available under names such as EL and APO.

Examples of the monomer having a norbornene ring include norbornene of a bicyclic olefin which is an adduct of ethylene and cyclopentadiene, tetracyclododecene of a tetracyclic olefin to which cyclopentadiene is added,
Tricyclodecadiene (also called dicyclopentadiene), which is a dimer of cyclopentadiene and a tricyclic diene,
Tricyclodecene which is a tricyclic olefin in which a part of the unsaturated bond is saturated by hydrogenation, pentacyclopentadecadiene which is a trimer of cyclopentadiene and a pentacyclic diene, a part of the unsaturated bond Pentacyclopentadecene (also referred to as 2,3-dihydrodicyclopentadiene) which is a pentacyclic olefin in which is substituted by hydrogenation; Examples of the substituent include a derivative substituted with a group having no polar group such as an alkyl group, an alkylidene group, or an aromatic group, a hydrogenated derivative, or a derivative obtained by dehydrogenation thereof (for example, 2-norbornene, 5- Methyl-2-norbornene, 5,5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, 5-hexyl-2-norbornene, 5- Norbornene derivatives such as phenyl-2-norbornene, 5-octyl-2-norbornene, 5-octadecyl-2-norbornene, 5-ethylidene-2-norbornene, 1,4: 5,8-dimethano-1,2,3 4,4a, 5,8,8a-2,3-
Cyclopentadienooctahydronaphthalene, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,5
6,7,8,8a-octahydronaphthalene, 1,4:
5,10: 6,9-trimethano-1,2,3,4,4
a, 5,5a, 6,9,9a, 10,10a-Tetracyclododecene derivatives such as dodecahydro-2,3-cyclopentadienoanthracene); halogen, hydroxyl, ester, alkoxy, cyano, An amide group,
Substitutes (for example, 5-methoxy-carbonyl-2-norbornene, 5-cyano-2-norbornene, 5-methyl-5) substituted with a polar group such as an imide group and a silyl group.
-Methoxycarbonyl-2-norbornene).

Examples of the α-olefin include olefin monomers having a narrow sense such as ethylene, propylene, 1-butene and 4-methylpentene-1, and olefinic monomers in which a part thereof is substituted with a polar group such as halogen. Can be.

As the cyclic olefin, cyclobutene,
1-methylcyclopentene, 3-methylcyclobutene,
Monocyclic cycloolefins such as 3,4-diisopropenylcyclobutene, cyclopentene, 3-methylcyclopentene, cyclohexene, cyclooctene, 1-methylcyclooctene, 5-methylcyclooctene, cyclooctatetraene, cyclododecene, and the above-mentioned norbornene Among the monomers having a ring, those having one unsaturated bond can be mentioned.

Examples of the cyclic diene include monocyclic dienes such as cyclopentadiene, 1,3-cyclohexadiene and 1,4-cyclohexadiene, and those having two unsaturated bonds among the above-mentioned monomers having a norbornene ring. be able to.

Further, in both the ring-opening polymerization and the addition polymerization, various copolymerizable monomers may be copolymerized in the respective catalyst systems to be polymerized. Examples of the copolymerizable monomer include, in addition to the above-mentioned monomer having a norbornene ring, α-olefin, cyclic olefin, and cyclic diene, linear or branched dienes such as butadiene and isoprene. The polymerization may be random, block type, or alternating type, and when addition polymerization involves 1,2-addition and 1,4-addition, either one may be the main.

When unsaturated bonds remain in the polymer after polymerization,
In other words, in the case of a ring-opened polymer of a monomer having a norbornene ring or an addition polymer of a cyclic diene, the weather resistance and thermal stability of the polymer are reduced due to the remaining unsaturated bonds. For the purpose of hydrogenation, 80% or more, preferably 9% of unsaturated bonds
It is preferable that 0% or more be used after being saturated. The hydrogenation method and the hydrogenation catalyst can be performed by a known method.

The molecular weight of the polymer is measured by gel permeation chromatography after dissolving it in a good solvent of the polymer such as toluene or tetrahydrofuran, and then measuring the solution by gel permeation chromatography. The number average molecular weight (Mn) is 12 in terms of polystyrene. It has a weight average molecular weight (Mw) of not less than 20,000 and not more than 80,000.

It is also preferable to remove or reduce the residue of the catalyst and the like from the polymer solution after the polymerization or after the hydrogenation reaction by a known method. The method for recovering the polymer from the polymer solution is not particularly limited, but it is important to remove residual volatile components as much as possible. After performing the washing method described in the catalyst removal method, the solvent is removed by a filtration method, and further heated, or a method of removing by vacuum heating, or directly heating the resin solution from which metal contaminants have been removed by a precipitation aggregation method, Alternatively, there is a method of removing the solvent by heating under vacuum.

The heat resistance of the cyclic olefin resin is described, for example, by a glass transition temperature. The glass transition temperature varies depending on the type of the monomer, the ratio of the comonomer when copolymerized, the molecular weight, the hydrogenation rate, and the like. When used as a substrate for an optical information recording medium disk, 60 to 22
0 ° C, preferably 70-200 ° C, more preferably 80 ° C.
~ 190 ° C is preferred.

Further, when used for an optical information recording medium disk, it is preferable that the cyclic olefin resin contains few foreign substances. As a method for suppressing foreign matter, for example, after the polymerization reaction or hydrogenation reaction, the pore size is 0.2μ
By filtering the polymer solution with a filter having a diameter of not more than m, metal residues and foreign substances can be precisely removed.

The cyclic olefin resin used in the present invention includes:
Various compounding agents usually used in the resin industry can be added and used.

Examples of the stabilizer include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. Of these, phenol-based antioxidants are preferred, and alkyl-substituted phenol-based antioxidants are preferred. Agents are particularly preferred. Furthermore, in order to prevent volatilization during molding,
It is desirable that the vapor pressure at 10 ° C. be 10 ⁻⁶ Pa or less.
These stabilizers are used alone or in combination of two or more. The amount of the stabilizer is appropriately selected according to the purpose of use.
It is usually in the range of 0.001 to 10 parts by weight with respect to 00 parts by weight.

A lubricant is used as needed for the purpose of improving moldability and the like. As a lubricant,
Partial ester of polyhydric alcohol, full ester of polyhydric alcohol (95% of alcoholic hydroxyl group of polyhydric alcohol)
% Of which are esterified), higher saturated alcohols, partial ethers of polyhydric alcohols and the like. Among them, full esters of polyhydric alcohols, especially full esters of polyhydric alcohols and OH group-containing higher saturated fatty acids, are mentioned. Esters are preferred, or higher saturated alcohols are particularly preferred. Furthermore, in order to prevent volatilization at the time of molding, it is desirable that the vapor pressure at 20 ° C. be 10 ⁻⁶ Pa or less. The blending amount of the lubricant is appropriately selected according to the purpose of use, but is usually 10 parts by weight or less, preferably 5 parts by weight or less, more preferably 3 parts by weight or less based on 100 parts by weight of the cyclic olefin polymer. Range. However, if the lubricant is used in a large amount, it oozes out of the surface of the molded product, for example, adheres to the surface of the molded product in the form of oil droplets, or it may adhere to the surface of the mold to lower the transferability. It is preferable that the amount used is about 1 part by weight or less.

For the purpose of improving the moisture resistance and moldability, a rubbery polymer may be blended. Generally, a rubbery polymer has a low glass transition temperature and may have low compatibility with a cyclic olefin resin.Therefore, if the compounding amount is large, the heat resistance as a mixture is lowered or the transparency is lowered. However, depending on the amount, addition method, kneading method, etc., the rubbery polymer in the cyclic olefin resin as the matrix may have a diameter of 0.3.
μm or less, especially 0.2 μm or less can be dispersed in the state of fine particles, and the diameter of the fine particles can be smaller than the wavelength of the laser used for the read signal of the optical information recording medium disk, so that light is not scattered. The signal characteristics do not deteriorate. In this case, the smaller the difference in the refractive index between the rubbery polymer and the cyclic olefin resin to be blended, the better the transparency of the cyclic olefin resin and the more preferable.

The rubbery polymer is disclosed in Japanese Patent Application Laid-Open No. 5-247.
No. 324, etc., are preferred. Specific examples thereof include styrene-based polymers such as styrene-butadiene rubber or a hydrogenated product thereof, styrene-isoprene-styrene block copolymer or a hydrogenated product thereof. Random or block copolymer; chloroprene rubber or hydrogenated product thereof; isoprene rubber or hydrogenated product thereof; ethylene-propylene copolymer, ethylene-α-
Olefin copolymer, propylene-α-olefin copolymer; and the like. Among these, hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene-styrene block copolymer, and the like are preferable from the viewpoint of heat resistance and a difference in refractive index.

The amount of the rubbery polymer varies depending on the refractive index difference between the rubbery polymer and the cyclic olefin resin as the matrix. 01 to 10 parts by weight, preferably 0.02 to 5 parts by weight, more preferably 0.05 to 1 part by weight
Parts by weight are preferred. This range is suitable because the adverse effect on the signal and the durability and moisture resistance are highly balanced.

Other compounding agents include, for example, dyes,
Examples include antistatic agents, ultraviolet absorbers, light stabilizers, waxes, and the like. These other compounding agents can be used alone or in combination of two or more.

The mixing of these components may be carried out by melt kneading with a kneader such as a single screw extruder, a twin screw extruder, a roll, or a Banbury mixer after isolating the cyclic olefin resin. It is preferable to add and mix with the above cyclic olefin resin solution. Further, the compounding agents may be added after dissolving each using an appropriate solvent, or may be added by heating the solution as necessary. The cyclic olefin resin solution may be heated similarly. The cyclic olefin resin is often used after being processed into a size of rice grain called a pellet so as to be easily handled at the time of injection molding. As described above, a necessary additive is added to the cyclic olefin resin to obtain a molding material composed of the cyclic olefin resin.

(Injection molding) Next, the optical information recording medium disk substrate is usually formed by injection molding or injection compression molding of the molding material comprising the above-mentioned cyclic olefin resin. A stamper is attached to the inner surface of the mold to transfer pits, grooves, and the like. The shape of the substrate can be changed according to the specification of the disc, the thickness is usually 0.5 to 3 mm, and the disc diameter is usually 30 mm to 300 mm.
mm. The pellets before molding may be preheated at 80 to 130 ° C. for 1 hour or more, preferably 2 hours or more, particularly preferably 4 hours or more, in order to suppress burn defects or the like. Heating may be performed in air, but under a nitrogen atmosphere or in a vacuum, deterioration during preheating can be suppressed,
More preferred.

The molding conditions are not particularly limited, but the cylinder set temperature of the molding machine is 200 to 400 ° C., preferably 2 to 400 ° C.
The mold temperature is preferably in the range of 50 to 380 ° C and the mold temperature is 50 to 180 ° C. If the temperature is too low, the transferability is lowered in any case, and the birefringence becomes large. If the temperature is too high, the molding cycle may be extended, burrs may occur, or the resin may be decomposed. Separate temperature of sprue,
For example, the temperature can be adjusted to 30 to 100 ° C. In order to suppress deterioration during molding, it is desirable to replace the inside of the molding machine heating cylinder with nitrogen (Optical Memory Symposium '88 Proceedings, pp. 15-16, 1988)
September 19, 2008).

(Corona discharge treatment) As a method for improving the adhesion between the cyclic olefin resin substrate and the ultraviolet-curable resin film layer, surface modification is effective.
48139 discloses a method of improving by oxygen plasma treatment,
Japanese Patent Application Laid-Open No. 4-372901 discloses that a method of improving by corona discharge treatment is effective. But,
In these methods, only the adhesion between the substrate and the ultraviolet-curable resin film layer is improved, and no mention is made of the improvement in the adhesion between the recording film layer and the reflection film layer. There is no disclosure or suggestion about a specific treatment method when a recording film layer exists between the recording film layer and the ultraviolet curable resin film layer. Even if only the adhesiveness between the substrate and the ultraviolet-curable resin film layer is improved, the durability of the optical information recording medium disk is not sufficient. It has been found that even if no defect occurs in the recording film layer, a minute defect occurs, and as a result, a bit error may occur.

Japanese Patent Application Laid-Open No. 4-348139 discloses that an optical information recording medium disk substrate is subjected to oxygen plasma processing. However, since plasma processing is performed in a vacuum chamber, the processing apparatus becomes large, and the processing speed is increased. However, the publication does not disclose a corona discharge treatment. Japanese Patent Application Laid-Open No. Hei 4-372901 discloses that a surface of a molded article made of a cyclic olefin resin such as a plastic lens is subjected to corona discharge treatment. However, an optical information recording medium disk, particularly an optical information recording medium having a recording film layer, is disclosed. It does not specifically disclose a method for processing a media disk. Furthermore, both plasma treatment and corona discharge treatment are unsuitable for treatment of electric conductors. For example, when corona discharge treatment is performed on a substrate on which an aluminum reflective film layer is formed, sparks may be generated and the substrate may burn or burn. Or As described above, it has not been known that the substrate of the optical information recording medium disk having the recording film layer is subjected to the corona discharge treatment, nor is the preferred treatment procedure and its effect.

The present invention is characterized in that a predetermined portion of the substrate is subjected to a corona discharge treatment before the formation of the recording film layer and the ultraviolet-curable resin film layer. Not only the adhesiveness of the resin film layer, but surprisingly, the adhesiveness between the substrate and the recording film layer, or the adhesiveness between the recording film layer and the ultraviolet-curable resin film layer, is improved.
It was unexpected from the above literature that the corona discharge treatment improves the adhesive strength between the lens and the ultraviolet-curable resin film layer.

The details of the processing will be described with reference to the drawings.

FIG.

In the present invention, a predetermined portion 2 of the surface of the molded substrate 1 (covering a portion on which either the recording film layer 3 or the ultraviolet curable resin film layer 4 is formed).
In addition, it is an essential requirement that a surface treatment by corona discharge treatment be performed before the recording film layer 3 is formed. By such a surface treatment, not only the adhesion between the substrate 1 and the ultraviolet-curable resin film layer 4 but also the adhesion between the substrate 1 and the recording film 3 and the adhesion between the recording film 3 and the ultraviolet-curable resin film layer 4 are improved. Be improved.

The irradiation conditions are not particularly limited, but the irradiation can be carried out in air at normal pressure, and there is no particular limitation on the environmental temperature.
The temperature of the substrate may be different from immediately after molding or after being left for a certain period of time, but since the substrate may be warped by its own weight during processing, the temperature is preferably equal to or lower than the thermal deformation temperature of the substrate material. The moving speed of the substrate during the processing may be arbitrarily adjusted according to the manufacturing process of the optical disk, and may be, for example, a speed of 0.1 to 10 m / min. Optical information recording medium disks are often circular and have a diameter of 85 mm, 130 mm, or the like. Therefore, even when they are arranged in a line, 1 to 100 sheets / minute can be processed.

The irradiation amount of the corona discharge treatment cannot be defined unconditionally because it varies depending on the intensity of the corona discharge and the processing apparatus. However, if the amount is too small, there is no effect, and if it is too large, the surface of the optical information recording medium disk substrate becomes rough. In a severe case, there is an inconvenience that the groove formed on the surface becomes shallow or chipped. The effect of the corona discharge treatment can be measured by the angle (water contact angle) between the water droplet and the substrate surface when a water droplet (pure water) is dropped on the substrate surface before and after the treatment. The angle falls and approaches a certain value.

FIG. 2 schematically shows this relationship.

FIG. 2 shows the amount of energy (referred to as irradiation amount) irradiated per unit area of the substrate surface, which corresponds to the irradiation time (or the reciprocal of the moving speed of the substrate) if the irradiation intensity is constant, Is the contact angle of water (the maximum value is 180 degrees). The contact angle of water is the contact angle before corona discharge treatment (11 in FIG. 2).
Therefore, the effect gradually decreases as the irradiation amount increases, and after sufficient irradiation, the effect gradually saturates to a constant value (13 in FIG. 2). Point corresponding to 0.9 times the effect of the saturated effect (contact angle of water = contact angle of water before treatment + (contact angle of water after saturation of effect−contact angle of water before treatment) × 0) .9,
Assuming that the irradiation amount for 12) in FIG. 2 is defined as D90, the irradiation amount is usually 0.3 × D90 to 100 × D90, preferably 0.4 × D90 to 50 × D90, and particularly preferably 0.1 × D90 to 50 × D90.
The range is 5 × D90 to 20 × D90. When in this range, the adhesion of the ultraviolet-curable resin film layer can be satisfactorily improved without roughening the substrate surface.

The output during irradiation is preferably 50 to 300 W. If it is low, the processing effect is weak and the adhesion is not improved. If it is too strong, the surface will be rough and the performance as an optical disc will be reduced. The distance between the substrate and the wire is usually 200 mm or less, preferably 100 mm or less, more preferably 60 m or less.
m or less, usually 2 mm or more, preferably 5 mm or more. If the distance is too large, the effect will be weak. If the distance is too small, the uniformity of the processing over the entire predetermined surface may be reduced.

A predetermined portion of the substrate surface on which the recording film layer is to be formed is subjected to a corona discharge treatment. Here, the predetermined portion is a portion where the recording layer is in contact with the substrate surface and a portion where the ultraviolet curable resin film layer is in contact with the substrate surface, which is the portion 2 in FIG. By subjecting these portions to corona discharge treatment, the adhesiveness between the recording film layer 3 and the ultraviolet curable resin film layer 4 is improved, and the recording film layer 3 is less affected by the environment outside the ultraviolet curable resin film layer. Furthermore, the durability of the optical information recording medium disk is greatly improved by making the recording film layer less susceptible to the environment near the boundary line 5 between the entire recording film surface and the portion with and without the recording film layer. You.

The surface on the opposite side of the substrate is not particularly processed, so that it is not necessary to perform corona discharge treatment. However, it may be performed as long as an ultraviolet curable resin film layer is formed. Further, another surface treatment method may be used in combination as needed. After the corona discharge treatment, the effect of the treatment may be weakened by various chemical components in the atmosphere, so perform the next step of forming the ultraviolet curable resin film layer before the elapse of a long time. Is preferred. Normally, it is one second or more and several days or less. In the case of a continuous process, considering the stability of the production process,
It is set within about 2 seconds to 10 minutes.

(Formation of Recording Film Layer) In the present invention, in the optical information recording medium disk, a layer that includes a reflective film layer and / or a recording film layer and that has an information recording function is called a recording film layer. . An optical information recording medium disk has an aluminum reflective film layer or a recording film layer that can locally change light reflectance irreversibly or reversibly on the surface of a substrate obtained by injection molding a thermoplastic resin. The recording film layer has a thickness of several hundreds to several thousand A, and at most 10,000 A or less. In the present invention, a recording film layer is formed in a portion of the surface of the substrate which has been subjected to the corona discharge treatment.

In a music CD, a CD-ROM, or the like, information itself is cut on a stamper portion of a mold at the time of injection molding, and a fine groove corresponding to the information is formed on the substrate. If a reflective film layer such as aluminum or gold is formed on the surface by sputtering or the like, the groove and the reflective film layer form a recording film layer.

In a write-once CD-R, a rewritable magneto-optical disk (MO), etc., a recording film layer that reversibly or irreversibly changes light reflectance or transmittance, and a reflection film that reflects light. Film layers and thin inorganic or organic protective film layers are formed to protect them or correct optical distortion. These layers are formed into a single layer or a multi-layer structure in combination with a method such as a sputtering method, a gaseous layer growth method, or a coating method using a chemical agent to form a layer functioning as information recording. For example, in a magneto-optical disk application, a magneto-optical recording medium (for example, Tb-Fe-C
o, Pt-Tb-Fe-Co, etc.); aluminum, gold and alloys thereof as a reflective layer; and a thin protective film layer of SiN, SiC or the like. In the case of a phase change type disc, Te-Ge-Sb, I
n-Sb-Te, Te-Ge-Cr, Te-Ge-Zn
For example, a recording film layer in which a reflective film layer similar to the above or a thin protective film layer is laminated on the above or an alloy thereof is used.

The thickness and forming method of these recording film layers differ depending on the type of each optical information recording medium disk, and are formed according to the standard by a known method.

(Formation of UV Curable Resin Film Layer) After the formation of the recording film layer, an ultraviolet curable resin film layer is further formed. As a coating agent for forming an ultraviolet-curable resin film layer, a method of applying an ultraviolet-curable acrylic-based coating agent, which is generally used for optical discs, by a spin coating method or the like and curing with an ultraviolet lamp is used. Although it is possible, a feature of the present invention is that an ultraviolet-curable resin film layer is formed on a portion of the substrate which has been subjected to corona discharge treatment with or without a recording film layer on the substrate (2 in FIG. 1). Portion), a recording film layer, and a boundary line between a portion with and without a recording film layer. By doing so, the adhesiveness between the recording film layer and the ultraviolet curable resin film layer and the adhesiveness between the recording film layer and the substrate are improved, and the durability of the optical information recording medium disk is improved.

The coating agent used for forming the resin film layer on the surface of the optical information recording medium disk may be a silicon-based coating agent. In terms of productivity,
An ultraviolet curable acrylic coating agent is used. The ultraviolet-curable coating agent of the present invention contains a reactive monomer and / or a reactive oligomer, a photopolymerization initiator, and other additives, and is a solvent-free or diluted with a solvent.

As the reactive monomer, acrylates are the main ones. Specifically, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-ethylhexyl methacrylate, phenoxyethyl acrylate, phenoxypropyl acrylate, Other monofunctional acrylate monomers such as higher alkyl acrylates; other monofunctional monomers such as styrene and vinylpyrrolidone; ethylene glycol, diethylene glycol, tripropylene glycol, butylene glycol, hexanediol, trimethylolpropane, tetramethylolpropane, and pentane Polyfunctional acrylate monomers in which two or more acrylates are bonded to a polyhydric alcohol such as erythritol; and the like. Examples of the reactive oligomer include polyester acrylate having an acroyl group at the end, epoxy acrylate or polyurethane acrylate having an epoxy group in the molecular chain and an acroyl group at the terminal, unsaturated polyester having a double bond in the molecular chain, and 1,2. Polybutadiene and other oligomers having epoxy or vinyl ether groups.

Examples of photopolymerization initiators include acetophenones such as 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone and chlorinated acetophenone; benzophenones; benzyl, methyl orthobenzoyl benzoate, and benzoin alkyl ether. Azo compounds such as α, α'-azobisisobutyronitrile, 2,2'-azobispropane and hydrazone; organic peroxides such as benzoyl peroxide and ditertiary butyl peroxide; diphenyldi Diphenyl disulfides such as sulfide, dibenzyl disulfide and dibenzoyl disulfide; and the like.

The mixing ratio of the monofunctional acrylate monomer is usually from 25 to 60% by weight, preferably from 30 to 40% by weight, based on the total weight of the acrylate monomer and the photopolymerization initiator. The monomer is 10 to 40% by weight, preferably 15 to 30% by weight, the tetrafunctional or higher acrylate monomer is 20 to 50% by weight, preferably 25 to 40% by weight, and the photopolymerization initiator is 1 to
It is 10% by weight, preferably 2 to 6% by weight. If the amount of the acrylate monomer having four or more functional groups is too large, the curing shrinkage increases. If the amount is too small, the hardness of the ultraviolet-curable resin film layer decreases, and the curing speed decreases. If the amount of the monofunctional acrylate monomer is small, the viscosity becomes high and the workability is poor. In addition, when the amount of the monofunctional acrylate monomer is large, the curing shrinkage decreases, and in addition, the amount of the bifunctional or trifunctional acrylate monomer decreases, and the flexibility of the ultraviolet curable resin film layer decreases, which causes cracks. In order to improve the adhesiveness, the amount of the bifunctional or trifunctional acrylate monomer is preferably large.

Further, as long as the adhesiveness and hardness of the ultraviolet-curable resin film layer are satisfied, a suitable additive may be added. For example, by adding a suitable surfactant, for example, a nonionic surfactant having good compatibility with an ultraviolet curing agent, in particular, an amine surfactant or other antistatic agent, the chargeability of the surface can be improved. Also, by adding a fluorine-based nonionic surfactant, wetting with the substrate and surface smoothness after the effect can be improved. Further, by adding an appropriate thermoplastic resin, the viscosity can be adjusted and the adhesiveness can be improved. As the thermoplastic resin for improving the adhesiveness, a cyclic olefin resin or a resin having a structure similar thereto, for example, a ring-opened polymer of a norbornene-based monomer, dicyclopentadiene-based, diene-based, aliphatic-based,
Examples thereof include petroleum resins such as water white resins and hydrogenated products thereof.

These mixtures can be used as such as a UV-curable coating agent, but if necessary, operability or the like, aromatic hydrocarbon solvents such as toluene, xylene and chlorobenzene; cyclohexane, methyl Alicyclic hydrocarbon solvents such as cyclohexane; ketone solvents such as methyl isobutyl ketone, methyl ethyl ketone and acetone; ether solvents such as n-butyl ether and diethyl ether; and the like, ester solvents, cellosolve solvents, chloro solvents. It may be dissolved in a solvent such as a solvent at a concentration of 80% by weight or more and used as an ultraviolet curable coating agent.

Further, from among those commercially available as an ultraviolet-curable coating agent, particularly an ultraviolet-curable coating agent for manufacturing an optical information recording medium disk, those having good adhesiveness to the cyclic olefin resin are appropriately selected and used. Examples of such specific examples include coating agents SD series manufactured by Dainippon Ink and Chemicals, particularly SD-301 and SD-301.
Mitsubishi Rayon UR series such as 1700, especially U
R-4501, Dr. Examples include various recording medium disc coating agents from Ranger.

(Method of Forming UV-Curable Resin Film Layer) In order to form the UV-curable resin film layer of the present invention, an ultraviolet-curable coating agent is applied to the surface on which the UV-curable resin film layer is to be formed and irradiated with ultraviolet rays. And cure. When the ultraviolet-curable coating agent is used by dissolving it in a solvent, the volatile components are sufficiently removed after the application of the ultraviolet-curable coating agent and before the next step.
If the UV-curable coating agent is cured while containing a large amount of solvent, cracks are likely to be generated in the coating film, and it also becomes a cause that a coating film with high hardness cannot be obtained.

The method of applying the ultraviolet curable coating agent is not particularly limited, and for example, spraying, dipping, spin coating, roll coater, etc. are possible. In the process of manufacturing an optical information recording medium disk, spin coating is commonly used. Is done. The method of removing the solvent when the solvent is used for the ultraviolet-curable coating agent is not particularly limited. When the solvent is substantially removed by volatilization, the required temperature and time vary depending on the type of the solvent used, the amount of coating, and the shape of the surface on which the ultraviolet-curable resin film layer is formed. The conditions may be determined so that the temperature is about 120 ° C. or less and volatile components can be sufficiently removed so as not to cause thermal deformation. Specifically, a removal method at 60 to 120 ° C. for about 3 to 60 minutes is suitable. After removing the solvent at a high temperature, it is preferable to perform cooling at room temperature for about 10 seconds to 10 minutes, and then cool to almost room temperature. When no solvent is used, the removal operation by volatilization is unnecessary.

It is preferable that the applied amount is set to a thickness of about 2 to 300 μm. When the solvent is removed, it is preferable that the solvent has the above thickness after the removal. If the amount of UV curable coating agent applied is small,
An ultraviolet-curable resin film layer with high strength cannot be obtained, and a sufficient effect of improving the surface hardness cannot be obtained. When the amount is too large, it takes time to remove the solvent and the curing reaction, resulting in poor productivity. In addition, when the curing is insufficient and the hardness is low, the ultraviolet curable resin film layer lacks flexibility and may be cracked.

Thereafter, by irradiating ultraviolet rays from a light source such as a high-pressure mercury lamp that efficiently generates ultraviolet rays, curing occurs in a short time, and an ultraviolet-curable resin film layer having high hardness is formed. The irradiation amount of the ultraviolet ray varies depending on the reactivity of the photopolymerizable monomer and the photopolymerization initiator, but a high-pressure mercury lamp of 80 to 200 W / cm is usually used.
When the irradiation intensity is 0 mJ / cm ² , the curing can be performed in a short time of about 1 to 20 seconds.

It is preferable to perform the surface treatment described in the present invention after the substrate is formed, and then continuously form the recording film layer and the protective coat. The series of steps is usually performed for 6 hours or less, preferably 1 hour or less, but may take 2 days or more due to troubles in the manufacturing process. It is also possible to form the protective coat layer after storage for several days after the formation of the recording film layer.

(Other Steps) For example, in the case of a digital video disk or a laser disk, it is also possible to use two disks each having a half thickness and bond the disks together so that the recording film layer is on the inside. . A label or the like can be further printed on the ultraviolet curable resin film layer by a screen printing method or the like. Further, each step defined in the manufacturing process of the present invention needs to be performed in the order of the method described in the claims, but it is also possible to add steps other than these steps. is there.

(Optical Information Recording Medium Disk) The optical information recording medium disk is manufactured by the above steps. The optical information recording medium disk according to the present invention is an optically readable information recording medium, a music CD, a CD-ROM, a laser disk, and the like, utilizing changes in reflected light due to minute irregularities, Non-rewritable ones, such as CD-Rs, minidiscs, MOs, and DVDs, can be added or rewritten using a change in reflectance due to a functional dye or phase change. In particular, for an optical information recording medium disk having a conductive film layer made of, for example, aluminum, gold, iron or the like and a compound containing these metal atoms as a reflective film layer, after forming the conductive film layer, There is a danger of discharge if you try to corona discharge
Although such a treatment was impossible, the use of the production method of the present invention is preferable because it does not cause burns or burns due to discharge and can improve the adhesive strength between the layers.

[0060]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Durability test) The recorded information can be taken out with good reproducibility over a long period of at least 10 years, preferably 20 years or more under the general use conditions of the optical information recording medium disk. (Standards for optical information recording medium disks are defined in “Red Book” and “Yellow Book”). However, it is not possible to actually test the durability after a lapse of 10 years, so that the test is usually performed under a sufficiently severe condition with a margin. Usually 50 to 10
0 ° C., preferably 60-95 ° C., usually 6 ° C.
In a humidity range of 0 to 100% RH, preferably 70 to 95% RH, durability acceleration is usually 100 hours or more, preferably 200 hours or more, more preferably 500 hours, and most preferably 1,000 hours or more. A test is performed to predict durability. The more severe the test conditions, the better the durability of the optical information recording medium disk. However, if the conditions are too severe, the quality will be excessive, resulting in an increase in cost and a decrease in the yield rate, which is not preferable. In addition, pass / fail after the endurance test was evaluated by first visually observing that the optical information recording medium disk had no abnormalities in appearance, and further electrically measuring the bit error rate (not completely zero). If it is below a certain level, it is judged as passing. Acceleration conditions such as high temperature and high humidity and the rate of occurrence of bit errors vary depending on the type and use of the optical information recording medium disk (computer or music), but usually 10 × 10 ^−6. Or less, preferably 1 × 10 ⁻⁶ or less.

(Test Items and Test Conditions) Test items and test conditions performed on the optical information recording medium disk will be described.・ Initial peeling test: After making 11 vertical and 11 horizontal cuts with a razor from the top of the ultraviolet curable resin film layer, draw 100 squares of 1 mm square, apply cellophane tape, peel off vigorously, and peel off ultraviolet rays Count the number of curable resin film layers,
Less than 10 pieces were good (o in Table 1), and 10 or more pieces were reject (x). -Initial bit error rate: The created optical information recording medium disk is placed in a predetermined case, and a magneto-optical disk medium comprehensive evaluation device OT-55 manufactured by Hitachi Electronics Engineering Co., Ltd.
The bit error rate was measured according to 00, and less than 1 × 10 ⁻⁶ was ^evaluated as good (○), and 1 × 10 ⁻⁶ or more was ^evaluated as unacceptable (×).・ Peeling test after durability promotion test: After conducting the durability promotion test under the specified conditions, the same test as the initial peel test was performed,
Good (O) and reject (X) were judged. -Bit error rate after durability promotion test: After a durability promotion test was performed under predetermined conditions, a test was performed in the same manner as the initial bit error rate, and good (O) and failed (X) were determined. -Appearance inspection after durability promotion test: After conducting the durability promotion test under the specified conditions, visually observe the appearance and check especially the occurrence of defects in the recording film layer. Tests were made to see if any had occurred, and good (no change) and failed (changed) were judged.

Example 1 (Production of a ring-opening polymer) 1,4-methano-1,4,4a, 9a was added to 690 parts by weight of dehydrated toluene under a nitrogen atmosphere.
300 parts by weight of tetrahydrofluorene are added together with 1.1 parts by weight of 1-hexene, 11 parts by weight of a 0.3% by weight solution of tungsten chloride in toluene and 0.6 part by weight of tetrabutyltin, and the mixture is added at 60 ° C. and normal pressure for 1 hour. Polymerized.
By high performance liquid chromatography (in terms of polystyrene) using toluene as a solvent, the number average molecular weight (Mn) of the obtained polymer was 17,700, and the weight average molecular weight was 35,
400 and the molecular weight distribution (Mw / Mn) was 2.0.

(Production of cyclic olefin resin) A nickel catalyst supported on alumina (containing 0.70 parts by weight of nickel and 0.2 parts by weight of nickel oxide per 1 part by weight of catalyst) was added to 240 parts by weight of the polymerization reaction solution. 8 cm ³ / g, specific surface area 300 cm ² / g) 6 parts by weight and isopropyl alcohol 5 parts by weight were added, and the mixture was heated at 230 ° C. in an autoclave.
The reaction was performed for 5 hours under the condition of 5 kgf / cm ² . This hydrogenation reaction solution was mixed with diatomaceous earth (Radiolite # 800) and activated alumina (pore volume 0.72 cm ³ / g, specific surface area 25
0 m ² / g) as a filter aid, the catalyst was removed, and the solution filtered through a membrane filter having a pore size of 0.4 μm was further filtered at 280 ° C. and 20 torr using a continuous centrifugal thin film evaporator dryer. After drying for 8 hours, a resin was obtained.
For 100 parts by weight of this resin, styrene-butadiene-
0.1 part by weight of a hydrogenated styrene block copolymer and 0.4 part by weight of tetrakis (methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate) methane After kneading with a twin screw extruder, pelletization was performed. The yield of the cyclic olefin resin was 99%. ^The main-chain hydrogenation rate measured by ¹ H-NMR was 99.9% or more, and the hydrogenation rate of the aromatic ring structure was 9%.
9.8%. The number average molecular weight (Mn) of the obtained hydrogenated product was 2 by high performance liquid chromatography (in terms of polyisoprene) using cyclohexane as a solvent.
2,600, weight average molecular weight (Mn) is 42,500,
The molecular weight distribution (Mw / Mn) was 1.88, and the glass transition point (Tg) was 136 ° C.

(Substrate molding) The above pellets were molded at a molding temperature of 3 using an injection molding machine (DISK) manufactured by Sumitomo Heavy Industries, Ltd. and a mold fitted with a stamper for a magneto-optical disk.
Injection molding was performed at a temperature of 40 ° C. and a mold temperature of 120 ° C. to obtain a 130 mmφ magneto-optical disk substrate. The water contact angle of the substrate measured after molding was 92 ° as measured in an environment of 25 ° C. and 40% RH.

(Corona discharge treatment) This substrate was treated with a corona discharge treatment device (tandem high frequency generator HV-0) manufactured by Tantec Corporation.
9, a high-voltage transformer, a type wire electrode) to perform a surface treatment over the entire surface having the groove. Processing conditions are as follows: air, room temperature 25 ° C, substrate temperature 25 ° C, conveyor moving speed 3m / min, output 200W, work distance 30mm.
Met. The water contact angle of the substrate measured after corona discharge treatment was 50 °.

(Formation of Recording Film Layer) ILC manufactured by Nidec Anelva
-3000 was used to form a recording film layer. The configuration of the recording film layer is SiN 100 nm, TbFeCo 30
nm, SiN 40 nm, and Al 40 nm. The recording film layer was not provided with a width of 1.0 mm at the outermost periphery and a width of 2.0 mm outside the groove at the inner periphery.

(Formation of Protective Coat Layer) Using a UV-curable resin SD-301 manufactured by Dainippon Ink and Chemicals Co., Ltd., application was performed by spin coating so as to cover the entire recording film layer, and a metal halide lamp (80 W / cm) was used. , The integrated irradiation dose is 3,0
Cured at 00 mJ / cm ² . Further, a separately molded hub was ultrasonically bonded to obtain a magneto-optical disk.

The magneto-optical disk obtained as described above was held at 70 ° C. and 80% RH for 1,000 hours, subjected to a durability promotion test, then cooled to room temperature, and subjected to a predetermined test. went. Table 1 shows the test results.

[Reference Experiment] The molded substrate obtained in Example 1 was subjected to corona discharge treatment 100 times repeatedly under the same conditions as in Example 1. The contact angle of water on the surface of the substrate after 100 times of corona discharge treatment was 45 °. When the substrate surface was observed with a scanning probe microscope Nanoscope IIIa (manufactured by Texas Instruments), the edge of the groove was rounded and the surface was rough.

Example 2 The substrate temperature during corona discharge was set to 7
A magneto-optical disk was obtained in the same manner as in Example 1 except that the temperature was changed to 0 ° C. Table 1 shows the test results.

Example 3 Under a nitrogen atmosphere, 60 parts by weight of ethyltetracyclododecene, 600 parts by weight of cyclohexane, 6.0 parts by weight of 1-hexene, 45 parts by weight of a 15% by weight solution of triethylaluminum in toluene and 15.0 parts by weight of triethylamine. Then, 240 parts by weight of ethyltetracyclododecene and 27.0 parts by weight of a 20% by weight titanium tetrachloride toluene solution are added to 60 parts by weight while maintaining the temperature at 20 ° C. and stirring.
Added continuously over minutes. Then, after reacting for 1 hour, 15.0 parts by weight of ethyl alcohol and 6.0 parts by weight of water were added to stop the reaction. After heating the reaction solution to 40 ° C. to hydrolyze the catalyst, 9 parts by weight of calcium sulfate and 180 parts by weight of cyclohexane were added to remove excess water.
The precipitate containing the deposited metal was removed by filtration to obtain a polymer solution. The number average molecular weight (M) of the obtained hydrogenated cyclic olefin resin was determined by high performance liquid chromatography (in terms of polyisoprene) using cyclohexane as a solvent.
n) is 21,000, the weight average molecular weight (Mn) is 44,
000, molecular weight distribution (Mw / Mn) was 2.10.

To 750 parts by weight of this polymer solution, 15 parts by weight of a Ni-diatomaceous earth catalyst were added, and the mixture was placed in an autoclave.
Hydrogen was introduced, the pressure was 50 kgf / cm ² , and the temperature was 200
A hydrogenation reaction was carried out at a temperature of 3 hours. After the reaction, 700 parts by weight of cyclohexane was added for dilution. This hydrogenation reaction solution was treated with diatomaceous earth (Radiolite # 800) and activated alumina (pore volume 0.72 cm ³ / g, specific surface area 250 m ²
/ G) was used as a filter aid to remove the catalyst, and the solution filtered through a membrane filter having a pore size of 0.4 μm was subjected to centrifugal thin-film continuous evaporator-type drying to obtain a solution.
The resin was dried at 80 ° C. and 20 torr for 8 hours to obtain a resin. To 100 parts by weight of this resin, 0.1 part by weight of hydrogenated styrene-butadiene-styrene block copolymer was added to tetrakis (methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxy). Phenyl) propionate) methane was added in a ratio of 0.3 parts by weight, and kneaded and pelletized with a twin-screw extruder.

The yield of the cyclic olefin resin was 99%. ^The hydrogenation rate by ¹ H-NMR was 99.9% or more. The number average molecular weight (M) of the obtained hydrogenated cyclic olefin resin was determined by high performance liquid chromatography (in terms of polyisoprene) using cyclohexane as a solvent.
n) was 28,000 and the weight average molecular weight (Mn) was 58,
000, the molecular weight distribution (Mw / Mn) was 2.07, and the glass transition point (Tg) was 142 ° C. This pellet was used to obtain a magneto-optical disk under the same conditions as in Example 1. Table 1 shows the test results.

Comparative Example 1 A magneto-optical disk was obtained in the same manner as in Example 1, except that the corona discharge treatment was not performed.
Table 1 shows the test results.

Comparative Example 2 A magneto-optical disk was obtained in the same manner as in Example 1, except that primer treatment was performed instead of corona discharge treatment. Primer treatment method is PC-7A
(Modified acrylic primer, manufactured by Shin-Etsu Chemical Co., Ltd.) was spin-coated on the substrate, dried at 110 ° C. for 1 hour, and then cooled to room temperature. The other steps are the same as in the first embodiment. Table 1 shows the test results.

Comparative Example 3 Example 1 was repeated except that a treatment with a dichromic acid-based aqueous solution was performed instead of the corona discharge treatment.
A magneto-optical disk was obtained in the same manner as described above. The treatment method using a dichromic acid-based aqueous solution is as follows: the substrate is immersed in a solution of potassium dichromate: water: sulfuric acid = 7: 12: 150 for 10 seconds, taken out, washed with water, dried at 100 ° C. for 30 minutes, and then room temperature. This was done by cooling to Other steps are the same as in the first embodiment. Table 1 shows the test results.

[0078]

[Table 1]

[0079]

According to the present invention, a method for manufacturing an optical information recording medium disk having excellent durability is provided, and a high quality music CD, CD-ROM, CD-R, magneto-optical disk, DVD is provided. And the like can be manufactured by the method of the present invention.

[0080]

[Brief description of the drawings]

FIG. 1 is a sectional view of an optical information recording medium disk and an enlarged view thereof.

FIG. 2 is a schematic graph showing the relationship between the irradiation amount of corona discharge treatment and the contact angle of water.

[Explanation of symbols]

 1: Substrate 2: Corona discharge treated part 3: Recording film layer 4: UV curable resin film layer 5: Boundary between part with and without recording film layer 6: Groove 11: Contact of water before corona discharge treatment Angle 12: Contact angle of water to D90 13: Contact angle of water after saturation of the effect 14: D90

Claims (1)

[Claims] 1. A step of obtaining a substrate by injection-molding a molding material comprising a cyclic olefin resin, and then a substrate surface in a portion where a recording film layer is formed as an upper layer and a portion where a UV-curable resin film layer is formed. A corona discharge treatment, then a step of forming a recording film layer on the surface of the substrate subjected to the corona discharge treatment, and then ultraviolet light so as to cover a boundary line between the entire recording film layer and a portion with and without the recording film layer. A method for manufacturing an optical information recording medium disk, comprising a step of forming a curable resin film layer. [0001]