JPH1040592A - Manufacture of stamper for optical disc and adhesive film for protecting stamper for optical disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing stemper without any environmental pollution which does not contaminate surface of the stamper for optical disc and shorten the working time, and an adhesive film for protecting stamper for optical disc to be used for the above method. SOLUTION: In a manufacturing method where the rear surface of stamper is polished by adhering in direct an adhesive film to the surface where projection and recess for pit and/or groove of the stamper for optical disc are formed and the internal and external diameter processings are made by the punching method, an adhesive film is formed of a base material film and an adhesive agent layer formed on one surface thereof, the adhesive agent layer contains a cross-linking agent of 0.1 to 30 pts.wt. having two or more crosslinking reactive function group in one molecule against the adhesive based polymer of 100 pts.wt. having the functional group which reacts with the cross-linking agent, an adhesive force for the SUS304-BA plate is 10 to 180g/25mm, average thickness of the adhesive film is 20 to 100μm and fluctuation of thickness is within ±5μm of the average thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a stamper for an optical disk. More specifically, an optical disk for recording and reproducing information using light, and a magneto-optical disk for recording, reproducing and erasing information using light and magnetism (hereinafter, referred to as “optical disk”).
The present invention relates to a backside polishing process of a stamper used in manufacturing an optical disk, and a method of processing an inner and outer diameter by a punching method. More specifically, in the manufacturing process of the stamper for an optical disk, the back surface (the surface on the opposite side on which the pit and / or groove irregularities are formed)
When polishing the surface of the substrate and when processing the inner and outer diameters by the punching method, the pit and / or groove forming surface (hereinafter referred to as signal uneven forming) of an optical disk stamper (hereinafter, referred to as a stamper) is formed. Surface or a stamper surface), which is directly attached to an adhesive film, and performs the processing while protecting the signal uneven surface. Another invention relates to an adhesive film for protecting a stamper for an optical disk used in the above method.

[0002]

2. Description of the Related Art An optical disk on which information is recorded, reproduced, and erased by using light or light and magnetism is used as an injection molding method, a compression molding method, an injection compression molding method, a photosensitive molding method using a stamper as a molding die. An optical disk substrate having pits and grooves formed on one side is manufactured by a method such as a reactive resin method (2P method), and a metal reflective layer, a protective layer, and the like are formed on this surface. Write-once or rewritable optical (magnetic) disks (CD
In the case of (-R, MO, etc.), a storage film made of an inorganic material such as an organic dye, a magnetic material, an alloy, or a metal oxide is formed between the substrate and the metal reflective layer, the protective layer, or the like. In general, pits refer to holes for recording signals for reproducing audio, video, information, etc., as well as address information and information for indicating the characteristics of a disc, and grooves refer to write-once and rewritable types. A guide groove for signal recording used in the case of an optical (magnetic) disk.

Usually, in a stamper manufacturing process, first, a recording master is prepared. As the master, a glass material with high surface accuracy is used. Next, a photoresist film as a photosensitive material is applied on the polished master. The photosensitive film is exposed by a laser beam to cut necessary information. When the cutting is completed, development is performed and signal irregularities are formed on the glass master. next,
After the signal concavo-convex formation surface is converted into a conductor, information is copied from a glass master as a metal (usually Ni) master by electroforming. The metal master is peeled off from the glass master, the back surface thereof is polished, the inner and outer diameters are processed, and the stamper is cut to a predetermined size. In general, in the case of the read-only type, information is copied as pits and projections, and in the case of the write-once type and rewritable type, information is copied as pits and grooves.

When an optical disk substrate is manufactured by using the stamper manufactured as described above, for example, by injection molding, injection compression molding, or the like, in the stamper manufacturing process described above, the stamper whose back surface is sufficiently polished is made of gold. Attached to the mold. At the time of injection (compression) molding, about 400 to 600
This is because the resin pressure of kg / cm ² is applied, so that the surface roughness of the back surface of the stamper and the unevenness of the thickness of the stamper appear on the stamper surface and greatly affect the characteristics of the resin substrate to be transferred.

[0005] During the stamper manufacturing process as described above,
When performing the backside polishing step and the inner / outer diameter processing step of the stamper, it is necessary to protect the signal irregularity forming surface.

As a method for manufacturing a stamper while protecting such a signal uneven surface, for example, Japanese Patent Application Laid-Open No.
No. 216915 discloses that a release assisting sheet having a uniform film thickness larger than the outer diameter of a metal stamper to be polished is disposed at the center of a disk-shaped metal plate, and the release auxiliary sheet is placed on the disk-shaped metal plate surface. After attaching a double-sided pressure-sensitive adhesive sheet so as to cover and fixing a metal stamper having a signal-coated protective surface on the double-sided pressure-sensitive adhesive sheet with its signal side corresponding to the double-sided pressure-sensitive adhesive sheet, the metal stamper is polished or wrapped. A metal stamper rear surface polishing method for polishing the rear surface of the metal stamper is disclosed.

Japanese Patent Application Laid-Open No. 63-247932 discloses a process in which a protective film is provided on the surface of a stamper which has been subjected to an electroforming process, and the surface having the protective film is directed toward the substrate to bond the stamper to the substrate. In the manufacture of the provided stamper, the stamper is 10 m in diameter from the final outer diameter.
m, wherein the stamper is provided with a portion lacking the protective film at a portion where the outer diameter of the stamper is increased, and the missing portion is used for bonding to the substrate. Is disclosed.

Heretofore, as described above, when manufacturing a stamper, it has been practiced to protect the signal concavo-convex formation surface with some kind of protective layer. These protective layers are formed by applying and drying a polymer solution by a spin coating method or the like. Since the polymer solution for the protective layer contains an organic solvent, a large-scale local exhaust facility must be provided. However, it is not practical to provide a large-scale local exhaust system in a clean room, considering that a polymer protective layer is usually formed in a clean room to maintain the cleanliness of the stamper. Further, the polymer protective layer is difficult to completely remove even if washed with an organic solvent, and often remains in a trace amount, which causes contamination of the stamper.

The characteristics required for the protective layer include the uniformity of the protective layer itself for obtaining the surface roughness of the back surface of the stamper and the uniformity of the thickness of the stamper, and the absence of defects on the surface on which the signal unevenness is formed. Cleanliness free from contamination and easy removal are required. However, in order to satisfy the characteristics required for the protective layer, advanced management is required. That is, it is necessary to filter the polymer solution with a filter, maintain the viscosity of the polymer solution in a predetermined range, and the like. Further, it is necessary to sufficiently dry the polymer protective layer, but it takes a long time to apply, dry, and cure the solution, and this is not a method that can satisfy workability. If the film shrinks during the formation of the protective layer, warping of the stamper itself becomes a problem.

[0010]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to eliminate contamination on the surface of a stamper, shorten the operation time, and eliminate environmental pollution by an organic solvent.
It is to provide a more rational stamper manufacturing method. Another object is to provide an adhesive film for protecting a stamper used in the above method.

[0011]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that in the back surface polishing step during the manufacturing process of the stamper for an optical disc and the inner and outer diameter processing step by the punching method, the uneven surface for signal formation of the stamper is formed. The present inventors have found that the above object can be achieved by directly attaching a specific pressure-sensitive adhesive film via the pressure-sensitive adhesive layer, and reached the present invention.

That is, according to the present invention, the pit and / or groove forming surface of the stamper for an optical disk is provided with
A method of manufacturing a stamper for an optical disc in which an adhesive film is directly adhered and the backside of the stamper is polished, and the inner and outer diameters are processed by a punching method, wherein the adhesive film is formed on a base film and one surface thereof. The adhesive layer has an average thickness of 20 to 100 μm, the thickness variation is within ± 5 μm of the average thickness, and the adhesive layer has 100 parts by weight of an adhesive polymer having a functional group capable of reacting with a crosslinking agent. On the other hand, SU contains 0.1 to 30 parts by weight of a crosslinking agent having two or more crosslinking reactive functional groups in one molecule,
Adhesive strength to S304-BA plate is 10 to 180 g / 2
A method for manufacturing a stamper for an optical disc, characterized in that the stamper is 5 mm. Another invention is a pressure-sensitive adhesive film for protecting a stamper for an optical disk used in the manufacturing method.

A feature of the present invention is that a specific adhesive film is directly adhered to the signal concavo-convex forming surface of the stamper in the back surface polishing process in the manufacturing process of the stamper for an optical disc and the inner and outer diameter machining process by a punching method. It is in. In the pressure-sensitive adhesive film used in the present invention, since the pressure-sensitive adhesive layer contains a specific amount of a cross-linking agent, no contamination due to the pressure-sensitive adhesive remains after peeling. In addition, since the adhesive strength is limited to a specific range, the stamper firmly adheres during polishing of the back surface of the stamper, and the stamper is not deformed by peeling stress when peeling. Further, since the thickness of the pressure-sensitive adhesive film is limited to a specific range, a load is not applied to the punching blade at the time of inner and outer diameter processing by punching, and deformation of the stamper due to poor punching does not occur. Further, according to the present invention, there is no need to form a protective layer by spin coating a polymer solution on the signal uneven surface of the stamper. Therefore, a solution application, a drying operation, and the like for forming the protective layer can be omitted, and the operation time can be greatly reduced. Since there is no generation of organic solvent gas when drying the applied polymer solution,
There is no risk of polluting the environment. Thus, according to the present invention,
It is possible to improve workability in the manufacturing process of the stamper for an optical disc, prevent environmental pollution, and the like.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The optical disk stamper according to the present invention is not limited to a stamper used for manufacturing a read-only optical disk capable of reproducing information using light, such as a compact disk (CD) and a video disk (LD). It also includes a stamper used for manufacturing a write-once or rewritable optical disk, a magneto-optical disk, or the like, which can record, reproduce, and erase information using light or light and magnetism.

According to the present invention, an adhesive layer is formed on one surface of a substrate film in a back surface polishing step in a manufacturing step of a stamper and in an inner and outer diameter processing step by a punching method. A specific adhesive film with a release film disposed on the surface of the agent layer (the release film is peeled off when pasting) is attached to the signal uneven surface of the stamper via the surface of the adhesive layer, and the back surface is polished. processing,
And a stamper manufacturing method for processing the inner and outer diameters by a punching method. Another invention is a pressure-sensitive adhesive film for protecting a stamper for an optical disk used in the above method.

First, a method for manufacturing an optical disk stamper according to the present invention will be described. Through a series of steps, a stamper before processing having signal irregularities on its surface is manufactured. The release film is peeled off from the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film, the surface of the pressure-sensitive adhesive layer is exposed, and the surface of the pressure-sensitive adhesive layer is adhered to the uneven surface of the stamper before processing through the pressure-sensitive adhesive layer. Next, the stamper is fixed to the polishing jig board through the base film layer of the adhesive film using a vacuum device or the like, and the back surface of the stamper is polished. After finishing the polishing, the inner and outer diameters are processed by punching in order to adjust to a predetermined size with the adhesive film adhered. After finishing the inner and outer diameter processing, the adhesive film is peeled off. After the peeling, a cleaning process such as water washing or plasma washing may be performed on the signal unevenness forming surface as needed. Further, the adhesive film may be stored for a certain period without being peeled off.

In the present invention, the order of the back surface polishing step and the step of processing the inner and outer diameters by punching may be appropriately changed depending on the type of stamper to be manufactured, the manufacturing method, and the like. In the present invention, there is no particular limitation on the inner and outer diameter machining methods by the back surface polishing method and the punching method, and any known method may be used.

Next, an adhesive film for protecting a stamper for an optical disk according to another embodiment of the present invention will be described. The pressure-sensitive adhesive film for protecting a stamper for an optical disk used in the present invention (hereinafter referred to as a pressure-sensitive adhesive film) is a solution containing a pressure-sensitive adhesive polymer, a crosslinking agent and, if necessary, other additives on one surface of a base film or a release film. Alternatively, it is produced by applying an emulsion liquid (hereinafter collectively referred to as an adhesive coating liquid) and drying to form an adhesive layer.

When a pressure-sensitive adhesive layer is formed on a substrate film, it is preferable to attach a release film to the surface of the pressure-sensitive adhesive layer in order to protect it from contamination due to the environment. In the case where an adhesive layer is formed on one surface of the release film, a method of transferring the adhesive layer to a base film is employed. Which surface of the base film or release film is to be coated with the adhesive coating liquid is determined in consideration of the heat resistance of the base film and release film, and the contamination of the optical disc stamper with the signal irregularity formed surface. . For example, when the heat resistance of the release film is superior to that of the base film, an adhesive layer is provided on the surface of the release film and then transferred to the base film. When the heat resistance is the same or the base film is excellent, an adhesive layer is provided on the surface of the base film, and a release film is attached to the surface of the adhesive layer.

In consideration of the fact that the pressure-sensitive adhesive film used in the present invention is adhered to the signal unevenness forming surface of the stamper via the surface of the pressure-sensitive adhesive layer exposed when the release film is peeled off, information from the pressure-sensitive adhesive layer is taken into consideration. In order to prevent the recording surface from being contaminated, it is preferable to use a release film having good heat resistance, apply a pressure-sensitive adhesive coating solution to the surface, and dry the surface to form a pressure-sensitive adhesive layer.

Examples of the base film of the pressure-sensitive adhesive film used in the present invention include films manufactured from synthetic resin, natural rubber, synthetic rubber, and the like. To give a concrete example,
Polyolefin, polyester, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, polybutadiene, soft vinyl chloride resin, polyamide, ionomer, and other resins, and their copolymer elastomers, and diene, nitrile, and silicone And films of synthetic rubber such as acryl based. The base film may be a single layer or a laminate.

The thickness of the base film is the sum of the thickness of the pressure-sensitive adhesive layer described later, that is, the thickness of the pressure-sensitive adhesive film is 20 to 10
It is preferable to select the thickness to be 0 μm. A more preferred thickness of the pressure-sensitive adhesive film is 25 to 80 μm. The thickness of the pressure-sensitive adhesive film affects the prevention of damage to the stamper in the stamper back surface polishing step, the workability of attaching and detaching the stamper to the signal uneven surface, and the workability in the inner and outer diameter processing step by a punching method. . When the thickness is reduced, the workability and ability to protect the signal surface of the stamper tend to decrease.When the thickness is increased, the punching blade is burdened in the machining process of the inner and outer diameters, resulting in poor cutting or distortion in the vicinity of the cut surface and the stamper. May be deformed.

The base film is preferably manufactured by controlling the thickness variation so as not to affect the thickness variation of the pressure-sensitive adhesive film described later. In order to improve the adhesive strength between the substrate film and the pressure-sensitive adhesive layer, it is preferable to subject the surface of the substrate film on which the pressure-sensitive adhesive layer is provided to a corona discharge treatment or a chemical treatment. An undercoat may be used between the base film and the pressure-sensitive adhesive layer.

When the release film is peeled off from the adhesive film, the workability is reduced due to static electricity generated when the adhesive film is peeled off from the stamper, or external contaminants adhere to the signal uneven surface of the stamper. In consideration of the fact that it becomes easier, it is preferable to perform an antistatic treatment on the surface of the base film opposite to the pressure-sensitive adhesive layer. Examples of the antistatic treatment method include a method of applying an antistatic agent such as a surfactant, a method of performing corona discharge treatment, and the like.

Depending on the method and apparatus of inner and outer diameter processing by back grinding or punching, the surface of the base film opposite to the pressure-sensitive adhesive layer (for protecting the uneven surface for the stamper signal) is formed on a processing jig board or the like. An adhesive layer for fixing may be provided. In this case, it is not necessary to provide a fixing device such as a vacuum suction device in the processing device. However, when the fixing pressure-sensitive adhesive layer is provided, it is preferable that the pressure-sensitive adhesive layer is provided so that the thickness variation of the entire pressure-sensitive adhesive film falls within a preferable range described later. In addition, it is necessary to consider the load on the punching blade during inner and outer diameter processing by the punching method. Further, it is preferable to adjust the adhesive strength between the fixing pressure-sensitive adhesive layer and the processing jig board so that the stamper can be peeled off after the processing without deforming the stamper. For example, an easy peeling process is performed on the jig board side.

Examples of the release film of the adhesive film used in the present invention include synthetic resin films such as polypropylene and polyethylene terephthalate. Preferably, the surface thereof is subjected to a silicone treatment or the like as necessary. The thickness of the release film is usually from 10 to 150 μm. Preferably it is 30 to 100 μm.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film used in the present invention is formed by applying a pressure-sensitive adhesive coating solution to one surface of a base film or a release film and drying.

The pressure-sensitive adhesive coating solution contains a pressure-sensitive adhesive polymer which is a basic component thereof, and a cross-linking agent having two or more cross-linking reactive functional groups in one molecule for increasing cohesive force or adjusting the adhesive force. Containing solution or emulsion. A tackifier such as a rosin-based resin or a terpene-based resin may be appropriately added to adjust the adhesive properties. When the pressure-sensitive adhesive polymer is an emulsion, a film-forming auxiliary such as diethylene glycol monoalkyl ether may be added.

Examples of the pressure-sensitive adhesive polymer constituting the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film used in the present invention include various synthetic rubber polymers having a functional group capable of undergoing a crosslinking reaction with a crosslinking agent. Among these, in consideration of control of adhesive properties, reproducibility, etc., alkyl acrylate polymers, alkyl methacrylate polymers, butadiene polymers, isoprene polymers, styrene-butadiene polymers and the like can be mentioned. Of these, alkyl acrylate polymers and alkyl methacrylate polymers are preferred. The liquid containing the pressure-sensitive adhesive polymer (hereinafter, pressure-sensitive adhesive main agent) may be any of a solution, an emulsion liquid, and the like.

When the pressure-sensitive adhesive polymer is an alkyl acrylate polymer or an alkyl methacrylate polymer, the main monomers constituting the pressure-sensitive adhesive polymer are methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate. And alkyl acrylates such as butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate, and alkyl methacrylates. These may be used alone or as a mixture of two or more. It is preferable that the amount of the main monomer used is usually in the range of 60 to 99% by weight in the total amount of all the monomers used as the raw material of the pressure-sensitive adhesive polymer.

Examples of comonomers having a functional group capable of reacting with a crosslinking agent, which are copolymerized with the above main monomer, include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid, citraconic acid, fumaric acid, maleic acid and monoalkyl itaconate. , Monoalkyl mesaconate, monoalkyl citraconic, monoalkyl fumarate, monoalkyl maleate, acrylic acid-
2-hydroxyethyl, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide, tert-butylaminoethyl acrylate, tert-butylaminoethyl methacrylate, and the like. One of these may be copolymerized with the above main monomer, or two or more thereof may be copolymerized. The amount of the comonomer having a functional group capable of reacting with the cross-linking agent is usually 1 to 10
Preferably, it is contained in the range of 40% by weight.

In the present invention, in addition to a comonomer having a functional group capable of reacting with the main monomer and the crosslinking agent constituting the pressure-sensitive adhesive polymer, a specific comonomer having a property as a surfactant (hereinafter referred to as a polymerizable surfactant) Agent)
May be copolymerized. The polymerizable surfactant has a property of copolymerizing with the main monomer and the comonomer, and has an action as an emulsifier when emulsion polymerization is performed. When a pressure-sensitive adhesive polymer emulsion-polymerized with a polymerizable surfactant is used, the surfactant usually does not cause contamination of the signal concavo-convex forming surface of the stamper. Further, even when slight contamination caused by the pressure-sensitive adhesive layer occurs, the signal irregularity-formed surface can be easily removed by washing with water. Examples of such a polymerizable surfactant include, for example, those obtained by introducing a polymerizable 1-propenyl group into a benzene ring of polyoxyethylene nonylphenyl ether [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd .; Aqualon RN-10] , RN-
20, RN-30, RN-50, etc.], and a polymerizable 1-propenyl group introduced into the benzene ring of the ammonium salt of a sulfate of polyoxyethylene nonylphenyl ether [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. AQUALON HS-
10, HS-20, etc.] and a sulfosuccinic acid diester having a polymerizable two bond in the molecule [Kao Corporation]
Manufactured by Latemul S-120A and S-180A].

In addition to the main monomer, a comonomer having a functional group capable of reacting with a crosslinking agent, and a polymerizable surfactant, glycidyl acrylate, glycidyl methacrylate, isocyanate ethyl acrylate, isocyanate ethyl methacrylate, (1-aziridinyl)
Monomers having a self-crosslinkable functional group such as ethyl acrylate and 2- (1-aziridinyl) ethyl methacrylate; monomers having a polymerizable double bond such as vinyl acetate, acrylonitrile, and styrene; divinylbenzene, vinyl acrylate, and methacrylic acid Polyfunctional monomers such as vinyl, allyl acrylate and allyl methacrylate may be copolymerized.

As a method of polymerizing the pressure-sensitive adhesive polymer,
Various known methods such as a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method can be employed, but it is preferable to consider the molecular weight of the obtained pressure-sensitive adhesive polymer and the accompanying effect on the cohesive strength of the pressure-sensitive adhesive. Among these polymerization methods, the emulsion polymerization method is preferable in consideration of obtaining a high molecular weight polymer, environmental pollution in coating and drying steps, coating properties, and the like.

As the polymerization reaction mechanism of the pressure-sensitive adhesive polymer,
Radical polymerization, anionic polymerization, cationic polymerization and the like can be mentioned, but polymerization is preferably performed by radical polymerization in consideration of the production cost of the pressure-sensitive adhesive, the influence of the functional group of the monomer, and the like. When polymerizing by a radical polymerization reaction, organic radicals such as benzoyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide are used as radical polymerization initiators. Inorganic peroxides such as peroxide, ammonium persulfate, potassium persulfate and sodium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-
Examples include azo compounds such as methylbutyronitrile and 4,4'-azobis-4-cyanovaleric acid.

The cross-linking agent used in the present invention is a compound having two or more cross-linking reactive functional groups in one molecule, and controls the cross-linking reaction with the functional group of the pressure-sensitive adhesive polymer to adjust the cohesive strength and cohesive strength. Used for Examples of the crosslinking agent include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resorcin diglycidyl ether. , Tetramethylene diisocyanate, hexamethylene diisocyanate,
Toluene diisocyanate of trimethylolpropane 3
Adducts, isocyanate compounds such as polyisocyanates, trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-
Aziridinyl propionate, N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide), N, N'-hexamethylene-1,6-bis (1-
Aziridine carboxamide), N, N'-toluene-
Aziridine compounds such as 2,4-bis (1-aziridinecarboxamide) and trimethylolpropane-tri-β- (2-methylaziridine) propionate; and melamine compounds such as hexamethoxymethylolmelamine.

These may be used alone or in combination of two or more. Among the above cross-linking agents, the epoxy-based cross-linking agent has a low speed of the cross-linking reaction, and when the reaction does not proceed sufficiently, the cohesive force of the pressure-sensitive adhesive layer decreases, and depending on the state of the stamper surface, the polishing method, etc. Contamination due to layers may occur. Therefore, as appropriate, a catalyst such as an amine is added, or a monomer having an amine functional group having a catalytic action is copolymerized with an adhesive polymer, or an aziridine-based compound having an amine property when a crosslinking agent is used. It is preferable to use a crosslinking agent together.

The amount of the cross-linking agent to be added is usually within a range such that the number of functional groups in the cross-linking agent does not become larger than the number of functional groups in the pressure-sensitive adhesive polymer. However, when a new functional group is generated by the crosslinking reaction or when the crosslinking reaction is slow, an excessive amount may be added as necessary. The amount of the crosslinking agent added is preferably 0.1 to 30 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer.

The adhesive strength of the adhesive film affects the protection of the signal irregularity forming surface during polishing of the back surface of the stamper, the workability of peeling from the stamper, the deformation of the stamper due to the peeling stress, and the like. From this viewpoint, the adhesive strength of the adhesive film is usually preferably from 10 to 180 g / 25 mm in terms of the adhesive strength to the SUS304-BA plate. It is more preferably 10 to 100 g / 25 mm, and still more preferably 10 to 50 g / 25 mm. If the adhesive strength is too high, it is difficult to peel without deformation, and the peeling operation time is prolonged, and the stamper is deformed when the adhesive film is peeled off. Insufficiency of protection, such as intrusion between layers, affecting signal irregularities.

As a method of applying a pressure-sensitive adhesive coating solution to one surface of the base film or the release film, a conventionally known coating method, for example, a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater A coater method, a die coater method, or the like can be employed. The drying condition of the applied pressure-sensitive adhesive is not particularly limited, but generally, 8
It is preferable to dry in a temperature range of 0 to 200 ° C. for 10 seconds to 10 minutes. More preferably 80 to 170 ° C
For 15 seconds to 5 minutes.

The thickness of the pressure-sensitive adhesive layer depends on the surface shape of the stamper,
It is appropriately determined in consideration of the protection property at the time of polishing the back surface, the load on the punching blade at the time of inner and outer diameter processing, the adhesive strength at the time of peeling from the stamper, and the like. Usually, about 2 to 15 μm is preferable.
More preferably, it is 2 to 10 μm.

In the production of the pressure-sensitive adhesive film used in the present invention, after the drying of the pressure-sensitive adhesive coating solution is completed, the pressure-sensitive adhesive film is subjected to 40 to 80 to sufficiently promote the cross-linking reaction between the cross-linking agent and the pressure-sensitive adhesive polymer. It may be heated at a temperature of about 5 to 300 hours.

In the process of processing the inner and outer diameters, when the punching position is adjusted by an optical sensor, it is preferable that the adhesive film has good transparency. From this viewpoint, 400 nm
The light transmittance in the visible light region of about 800 nm is 4
A base film of 0% or more is preferred. More preferably 6
0% or more.

The thickness variation of the pressure-sensitive adhesive film affects the thickness variation of the stamper after polishing the back surface. Therefore,
The thickness variation of the pressure-sensitive adhesive film is preferably within ± 5 μm with respect to the average value of the thickness. More preferably, it is within ± 3 μm.

The method for producing the pressure-sensitive adhesive film used in the present invention is as described above, but from the viewpoint of preventing contamination of the signal irregularity surface of the stamper, all raw materials such as a base film, a release film, and a pressure-sensitive adhesive base material are used. Production environment, preparation, storage, application and drying environment of the adhesive coating solution is the US Federal Standard 209b
It is preferable to maintain the cleanliness of class 1,000 or less specified in the above. Also, in the method of manufacturing an optical disk of the present invention, it is preferable that the degree of cleanness be kept at a class of 1,000 or less similarly from the viewpoint of contamination of the signal uneven surface.

[0046]

The present invention will be described below in further detail with reference to examples. The present invention is not limited to these examples. The adhesive strength and thickness variation of the pressure-sensitive adhesive films obtained in Examples and Comparative Examples, and the thickness variation and surface contamination of the obtained stamper were evaluated by the following methods.

(1) Measurement of adhesive strength (g / 25 mm) Except for the conditions specified below, all were JIS Z-0237.
Measure according to Under an atmosphere of 23 ° C., a 5 × 20 cm SUS304-BA plate (JIS
G-4305) and left for 1 hour. One end of the sample was sandwiched, and a peeling angle of 180 ° and a peeling speed of 300 mm / min. Is used to measure the stress when the sample is peeled off from the surface of the SUS304-BA plate, and is converted to an adhesive force of g / 25 mm.

(2) Measurement of thickness variation of adhesive film (μm) 10c from the adhesive film obtained in Examples or Comparative Examples
A sample of m square size is taken at random. With the release film peeled off, the thickness of the pressure-sensitive adhesive film (total of the base film and the pressure-sensitive adhesive layer) is measured at a total of 100 points every 1 cm in length and width, and the average value is determined. The difference between the maximum value or the minimum value and the average value is taken, and the value (A) having the larger absolute value is regarded as the thickness variation, and is represented by ± A (μm).

(3) Measurement of Variation in Thickness of Stamper After Production (μm) The thickness of the portion of the stamper obtained in the example or the comparative example where signal irregularities are formed is randomly determined at regular intervals. 5
Measure at 0 points and determine the average value. The difference between the maximum value or the minimum value and the average value is taken, and the larger value (B) of the absolute value is defined as the thickness variation, and is represented by ± B (μm).

(4) Observation of contamination on the signal uneven surface of the stamper after manufacture The signal uneven surface of the stamper after manufacture, obtained in the example or the comparative example, was observed with a microscope (800 times) and contaminated. Assess the situation.

Example 1 In a polymerization reactor, 150 parts by weight of deionized water and 4,4'-azobis-4-cyanovaleric acid (trade name: ACVA, manufactured by Otsuka Chemical Co., Ltd.) as a polymerization initiator were used in an amount of 0%. 0.5 parts by weight, 73.25 parts by weight of butyl acrylate, 14 parts by weight of methyl methacrylate, 9 parts by weight of 2-hydroxyethyl methacrylate, 2 parts by weight of methacrylic acid, 1 part by weight of acrylamide, and poly as a polymerizable surfactant Oxyethylene nonylphenyl ether (average of the number of moles of ethylene oxide added: about 20) in which a polymerizable 1-propenyl group is introduced into the benzene ring of an ammonium salt of a sulfate [Daiichi Kogyo Seiyaku Co., Ltd. Made: Aqualon HS
-20], emulsion polymerization was carried out at 70 ° C. for 9 hours with stirring using 0.75 parts by weight to obtain an acrylic resin-based water emulsion. This is neutralized with 14% by weight ammonia water,
An adhesive polymer emulsion having a solid content of about 40% by weight (adhesive base) was obtained. The obtained adhesive base emulsion 1
00 parts by weight (adhesive polymer concentration: about 40% by weight) was collected, and 14% by weight aqueous ammonia was added thereto to adjust the pH to 9.3.
Was adjusted. Next, 4 parts by weight of an aziridine-based cross-linking agent (manufactured by Nippon Shokubai Chemical Co., Ltd., Chemitite PZ-33) and 5 parts by weight of diethylene glycol monobutyl ether were added to obtain an adhesive coating solution.

The pressure-sensitive adhesive coating solution was applied to a polypropylene film (release film, thickness: 50) using a roll coater.
μm) and dried at 120 ° C. for 1 minute to form a 3 μm thick pressure-sensitive adhesive layer. Next, the treated surface of a polyethylene terephthalate film (base film) having a thickness of 38 μm subjected to corona discharge treatment was bonded and pressed to transfer the pressure-sensitive adhesive layer. After the transfer, the film was heated at 60 ° C. for 48 hours, and then cooled to room temperature to produce an adhesive film. The adhesive strength of the obtained adhesive film to the SUS-304BA plate was 30 g / 25 mm, and the thickness variation was ±
2 μm, light transmittance at 400 nm to 800 nm is 75%
That was all.

The release film is peeled off from the obtained adhesive film, and a signal of a stamper (before processing) for a write-once compact disc (CD-R) having a thickness of about 0.3 mm is passed through the adhesive layer. After sticking to the uneven surface, the back surface of the stamper was polished. After polishing the back surface, the inner and outer diameters were processed by a punching method. At this time, the punching position was determined using an optical sensor. After the punching process was completed, the adhesive film was peeled off to produce a write-once compact disc (CD-R) stamper. The time required for attaching and detaching the pressure-sensitive adhesive film was a short time of about 1 minute in total, and did not require a special large-sized device. Also, no trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was as good as ± 2 μm or less. Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in [Table 1].

Example 2 An adhesive film was produced in the same manner as in Example 1 except that the thickness of the adhesive layer was changed to 2 μm. SUS-3 of the obtained adhesive film
The adhesive strength to the 04BA plate was 15 g / 25 mm, the thickness variation was ± 2 μm, and the light transmittance at 400 nm to 800 nm was 75% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. The time required for attaching and detaching the adhesive film was a short time of about 1 minute in total, and did not require a special large-sized device. Also, no trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was ± 2.
It was good within μm. Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in [Table 1].

Example 3 In the production of the pressure-sensitive adhesive film of Example 1, an aziridine-based crosslinking agent [Nippon Shokubai Kagaku Kogyo KK, Chemitite PZ-
No. 33] was prepared in the same manner as in Example 1 except that the addition amount was 3 parts by weight. The adhesive strength of the obtained adhesive film to the SUS-304BA plate is 45 g / 2.
5 mm, thickness variation ± 2 μm, 400 nm to 800
The light transmittance in nm was 75% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. The time required for attaching and detaching the adhesive film was a short time of about 1 minute in total, and did not require a special large-sized device. Also, no trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was as good as ± 2 μm or less. Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in [Table 1].

Example 4 In the production of the pressure-sensitive adhesive film of Example 1, an aziridine-based crosslinking agent [Nippon Shokubai Kagaku Kogyo KK, Chemitite PZ-
33] was added in an amount of 3 parts by weight, the thickness of the pressure-sensitive adhesive layer was 5 μm,
Polyethylene terephthalate film (base film)
A pressure-sensitive adhesive film was produced in the same manner as in Example 1 except that the thickness of the adhesive film was changed to 50 μm. SU of the obtained adhesive film
The adhesive strength to the S-304BA plate is 80 g / 25 mm,
The thickness variation was ± 3 μm, and the light transmittance from 400 nm to 800 nm was 70% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. The time required for attaching the adhesive film was about the same as in Example 1,
It took some time to peel off the stamper without deforming it. Nevertheless, the time required for sticking and peeling was about 5 minutes in total. Also, no special large-scale equipment was required. No trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was as good as ± 2 μm or less. Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in [Table 1].

Example 5 In the production of the pressure-sensitive adhesive film of Example 1, an aziridine-based crosslinking agent [Nippon Shokubai Kagaku Kogyo KK, Chemitite PZ-
33] was added at 3 parts by weight, and the thickness of the pressure-sensitive adhesive layer was 10 μm.
m, and a pressure-sensitive adhesive film was produced in the same manner as in Example 1, except that the thickness of the polyethylene terephthalate film (base film) was 60 μm. The adhesive strength of the obtained adhesive film to the SUS-304BA plate is 160 g / 25.
mm, thickness variation is ± 3 μm, 400 nm to 800 n
m had a light transmittance of 60% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. The time required for sticking the pressure-sensitive adhesive film was about the same as that of Example 1, but it took some time to peel off without deforming the stamper. Nevertheless, the time required for sticking and peeling was about 12 minutes in total. Also, no special large-scale equipment was required. No trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was as good as ± 2 μm or less. Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in Table 1.
Shown in

Comparative Example 1 In the production of the pressure-sensitive adhesive film of Example 1, an aziridine-based crosslinking agent [Chemiteite PZ-, manufactured by Nippon Shokubai Chemical Industry Co., Ltd.] was used.
33] was added at 2 parts by weight, and the thickness of the pressure-sensitive adhesive layer was 10 μm.
m, and a pressure-sensitive adhesive film was produced in the same manner as in Example 1, except that the thickness of the polyethylene terephthalate film (base film) was 50 μm. The adhesive strength of the obtained adhesive film to the SUS-304BA plate was 200 g / 25.
mm, thickness variation is ± 3 μm, 400 nm to 800 n
The light transmittance of m was 65% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. Although there was a particular problem in sticking the adhesive film, the stamper was deformed at the time of peeling. No trouble occurred during the punching process. The results are shown in [Table 1].

Comparative Example 2 In the production of the pressure-sensitive adhesive film of Example 1, the amount of butyl acrylate used was 66.25 parts by weight, the amount of methyl methacrylate used was 21 parts by weight, and an aziridine-based crosslinking agent [Nippon Shokubai Chemical Co., Ltd. Co., Ltd., Chemitite PZ-33] was added in an amount of 5 parts by weight, the thickness of the adhesive layer was 2 μm, and the thickness of the polyethylene terephthalate film (base film) was 50 μm.
A pressure-sensitive adhesive film was produced in the same manner as in Example 1 except that m was used. SUS-304BA of the obtained adhesive film
Adhesion to board is 8g / 25mm, thickness variation is ±
2 μm, light transmittance at 400 nm to 800 nm is 70%
That was all. Using the obtained adhesive film, a read-only compact disc (CD) in the same manner as in Example 1.
Was manufactured for the stamper. The time required for attaching and detaching the adhesive film was as short as about 1 minute in total, and no special large-sized device was required. No trouble occurred during the punching process. When the polishing conditions of the obtained stampers were evaluated, there were no local depressions, and the thickness variation of the stampers was as good as ± 2 μm or less. However, when the signal concavo-convex formation surface of the stamper was observed with a microscope (magnification: 800), some contamination due to infiltration of the abrasive was observed around the stamper. The results are shown in [Table 1].

Comparative Example 3 In the production of the pressure-sensitive adhesive film of Example 1, the pressure-sensitive adhesive layer had a thickness of 13 μm, the polyethylene terephthalate film had a thickness of 65 μm, and the pressure-sensitive adhesive layer and the polyethylene terephthalate film (base film) had a thickness of 13 μm. An adhesive film was manufactured in the same manner as in Example 1 except that the thickness variation was increased. SUS- of the obtained adhesive film
The adhesive strength to the 304BA plate was 110 g / 25 mm, the thickness variation was ± 7 μm, and the light transmittance at 400 nm to 800 nm was 50% or more. Using the obtained adhesive film, a reproduction-only compact disk (CD) stamper was manufactured in the same manner as in Example 1. The time required for sticking the pressure-sensitive adhesive film was about the same as that of Example 1, but it took some time to peel off without deforming the stamper.
Nevertheless, the time required for pasting and peeling was 10 in total
Minutes. Also, no special large-scale equipment was required. No trouble occurred during the punching process. When the polishing conditions of the obtained stamper were evaluated, there was no local dent, but the thickness variation of the stamper was ± 6 μm, which was a level that would cause problems when used for injection (compression) molding. . Further, when the signal concavo-convex formation surface of the stamper was observed with a microscope (× 800), no contaminants were found. The results are shown in [Table 1].

Comparative Example 4 An adhesive film was produced in the same manner as in Example 1 except that the thickness of the adhesive layer was 5 μm and the thickness of the polyethylene terephthalate film was 125 μm. SUS-3 of the obtained adhesive film
The adhesive strength to the 04BA plate was 50 g / 25 mm, the thickness variation was ± 3 μm, and the light transmittance at 400 to 800 mm was 40% or more. Using the obtained adhesive film,
Read-only compact disc (CD) as in the first embodiment
Was manufactured for the stamper. Insufficiency of cutting occurred during punching, and part of the stamper was deformed.

Comparative Example 5 A commercially available liquid for polymer protective film (trade name, manufactured by Fine Chemical Japan Co., Ltd., trade name: Clean Coat S) was added to a write-once compact disc (CD-
R) stamper (before polishing) on the signal uneven surface
After spin-coating to a thickness of about 30 μm after drying and drying for about 1 hour, the back surface of the stamper was polished.
In this case, a local exhaust system for exhausting the solvent and a large-scale spin coater with strictly controlled cleanliness were required. After the polishing, the inner and outer diameters were processed by a punching method. At this time, the punching position was determined using an optical sensor. After the punching process was completed, the protective film was peeled off and removed. However, at the time of peeling, a part of the protective film remained on the signal unevenness forming surface, and it was necessary to perform solvent cleaning. It took about one hour to wash the solvent. No trouble occurred during the punching process. When the polishing status of the obtained stamper was evaluated, no local dent was found, and the thickness variation of the stamper was as good as ± 2 μm or less.
Also, the signal uneven surface of the stamper is microscope (800x)
Observation, several foreign matter of about 3μm was found,
Further cleaning was required. The results are shown in [Table 1].

[0063]

[Table 1]

[0064]

The adhesive film for protecting a stamper for an optical disk used in the present invention has an appropriate adhesive force because its adhesive force is limited to a specific range, and a signal is applied during polishing of the back surface of the stamper. The stamper is firmly adhered to the extent that the surface for forming unevenness can be protected, and the stamper is not deformed by peeling stress when peeling. Since a specific amount of the crosslinking agent is contained, contamination due to the adhesive does not remain on the signal uneven surface after peeling. Further, since the thickness of the pressure-sensitive adhesive film is limited to a specific range, even if the inner and outer diameters are processed by the punching method, a load is not applied to the punching blade, and a problem such as defective cutting and deformation of the stamper due to the cutting failure. Does not occur.
Further, according to the present invention, there is no need to form a protective layer by spin coating a polymer solution on the signal uneven surface of the stamper. Therefore, a solution application, a drying operation, and the like for forming the protective layer can be omitted, and the operation time can be greatly reduced. Since there is no generation of organic solvent gas when drying the applied polymer solution, there is no risk of polluting the environment. Therefore, according to the present invention, it is possible to improve the workability at the time of manufacturing a stamper for an optical disc, prevent environmental pollution, and the like.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuko Fujii 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Mitsui Toatsu Chemicals Co., Ltd.

Claims (18)

[Claims] 1. An optical disc stamper, wherein an adhesive film is directly adhered to a pit unevenness and / or groove unevenness forming surface of the optical disc stamper, and a back surface polishing process of the stamper and an inner and outer diameter processing by a punching method are performed. The method according to claim 1, wherein the pressure-sensitive adhesive film comprises a base film and a pressure-sensitive adhesive layer formed on one surface thereof, and has an average thickness of 2
0 to 100 μm, the thickness variation is within ± 5 μm of the average thickness, and the pressure-sensitive adhesive layer is two or more per molecule with respect to 100 parts by weight of a pressure-sensitive adhesive polymer having a functional group capable of reacting with a crosslinking agent. A crosslinking agent having a crosslinking reactive functional group
A method for producing a stamper for an optical disk, comprising 1 to 30 parts by weight and having an adhesive strength to a SUS304-BA plate of 10 to 180 g / 25 mm. 2. The method according to claim 1, wherein the adhesive strength is 10 to 100 g / 25 mm. 3. The method according to claim 1, wherein the adhesive strength is 10 to 50 g / 25 mm. 4. The adhesive film has an average thickness of 25 to 80 μm.
2. The method according to claim 1, wherein m is m. 5. The method according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 2 to 15 μm. 6. The method according to claim 1, wherein the thickness variation of the adhesive film is within ± 3 μm of the average thickness. 7. The pressure-sensitive adhesive polymer, wherein a) at least one main monomer selected from the group consisting of a) alkyl acrylate and alkyl methacrylate 60 to 99.
% By weight, b) obtained by copolymerizing a monomer mixture containing 1 to 40% by weight of a comonomer having a functional group capable of reacting with at least one crosslinking agent selected from a hydroxyl group, a carboxyl group and an amino group. The method for manufacturing an optical disk stamper according to claim 1, wherein: 8. The crosslinker according to claim 1, wherein the crosslinker is at least one crosslinker selected from the group consisting of an epoxy crosslinker, an aziridine crosslinker, and an isocyanate crosslinker. Manufacturing method of stamper for optical disk. 9. The adhesive film has a light transmittance of 400 n.
40% or more at m to 800 nm, and
9. The method of manufacturing a stamper for an optical disk according to claim 1, wherein the punching position is adjusted by an optical sensor during inner and outer diameter processing by a punching method. 10. A back surface polishing process for an optical disc stamper,
And a pressure-sensitive adhesive film for protecting an optical disk stamper that is directly adhered to the pit unevenness and / or groove unevenness forming surface of the stamper when the inner and outer diameters are processed by a punching method. It consists of an adhesive layer formed on one surface, and has an average thickness of 20 to 10
0 μm, the thickness variation is within ± 5 μm of the average thickness, and the pressure-sensitive adhesive layer has two or more crosslinks per molecule with respect to 100 parts by weight of a pressure-sensitive adhesive polymer having a functional group capable of reacting with a crosslinker. Crosslinking agent having reactive functional group 0.1-3
An adhesive film for protecting a stamper for an optical disk, comprising 0 parts by weight and having an adhesive strength to a SUS304-BA plate of 10 to 180 g / 25 mm. 11. The adhesive film for protecting a stamper for an optical disk according to claim 10, wherein the adhesive force is 10 to 100 g / 25 mm. 12. The pressure-sensitive adhesive film for protecting a stamper for an optical disk according to claim 10, wherein the pressure-sensitive adhesive strength is 10 to 50 g / 25 mm. 13. The adhesive film has an average thickness of 25 to 80.
The pressure-sensitive adhesive film for protecting a stamper for an optical disk according to claim 10, wherein the thickness is μm. 14. The pressure-sensitive adhesive film according to claim 10, wherein the pressure-sensitive adhesive layer has a thickness of 2 to 15 μm. 15. The pressure-sensitive adhesive film according to claim 10, wherein the thickness variation is within ± 3 μm of the average thickness.
The adhesive film for protecting a stamper for an optical disc according to the above. 16. The pressure-sensitive adhesive polymer wherein a) at least one main monomer selected from the group consisting of: a) alkyl acrylates and alkyl methacrylates
9% by weight, b) obtained by copolymerizing a monomer mixture containing 1 to 40% by weight of a comonomer having a functional group capable of reacting with at least one crosslinking agent selected from a hydroxyl group, a carboxyl group and an amino group. The pressure-sensitive adhesive film for protecting a stamper for an optical disk according to claim 10, wherein the pressure-sensitive adhesive film is provided. 17. The method according to claim 10, wherein the crosslinking agent is at least one crosslinking agent selected from the group consisting of an epoxy crosslinking agent, an aziridine crosslinking agent, and an isocyanate crosslinking agent. Adhesive film for protecting stampers for optical discs. 18. The light transmittance of the adhesive film is 400.
18. The pressure-sensitive adhesive film for protecting a stamper for an optical disk according to claim 10, wherein the thickness is 40% or more in the wavelength range from nm to 800 nm.