JP3989755B2 - Optical disc manufacturing sheet - Google Patents

Description

【００８１】
表１から明らかなように、実施例１，２で製造した軽剥離シートを使用した光ディスク製造用シートにおいては、光硬化したスタンパー受容層の凹凸パターン転写面にはボイド状の欠点は見られず、比較例１，２で製造した軽剥離シートを使用した光ディスク製造用シートにおいては、光硬化したスタンパー受容層の凹凸パターン転写面にボイド状の欠点が見られた。
【００８２】
【発明の効果】
本発明によれば、硬化したスタンパー受容層の凹凸パターン転写面にボイド状の欠点が生じることが防止される。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る光ディスク製造用シートの断面図である。
【図２】同実施形態に係る光ディスク製造用シートを使用した光ディスク製造方法の一例を示す断面図である。
【図３】本発明の他の実施形態に係る光ディスク製造用シートの断面図である。
【符号の説明】
１，１’…光ディスク製造用シート
１１…スタンパー受容層
１２，１２’…剥離シート
１２１，１２１’…基材
１２２，１２２’…剥離剤層
１３…カバーシート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet for manufacturing an optical disk, and more particularly to a sheet for manufacturing an optical disk in which a stamper-receiving layer to which a concavo-convex pattern of a stamper is transferred does not easily cause a defect.
[0002]
[Prior art]
Conventionally, in the manufacture of optical disks, as a means for forming uneven shapes called pits or grooves for recording information, there is a method of transferring the uneven pattern from a stamper having an uneven pattern corresponding to the uneven shape to a constituent layer of the optical disk. Are known. As a layer to which the concavo-convex pattern is transferred, a stamper-receiving layer having a property that the concavo-convex pattern is fixed after the concavo-convex pattern is transferred from the stamper and cured by irradiation with an energy ray has been studied. . In general, a sheet for producing an optical disc having such a stamper-receiving layer has a structure in which one or both surfaces of the stamper-receiving layer are protected by a release sheet.
[0003]
[Problems to be solved by the invention]
The concavo-convex pattern transferred to the stamper-receiving layer constitutes important pits or grooves as recording information on the optical disk. Therefore, in order to accurately reproduce the recorded information, the concavo-convex pattern transfer surface of the stamper-receiving layer is It is desirable that there are no irregularities other than the irregular pattern.
[0004]
However, in the conventional sheet for optical disc production, when the uneven pattern transfer surface of the cured stamper-receiving layer is observed with an atomic force microscope, many nano-sized void-like defects are observed. If such a void-like defect exists on the concavo-convex pattern transfer surface of the cured stamper receiving layer, the defect part becomes a defect in the optical disc, and there is a possibility that the recorded information cannot be reproduced accurately.
[0005]
The present invention has been made in view of such a situation, and an object of the present invention is to provide a sheet for manufacturing an optical disc in which void-like defects are unlikely to occur on a concavo-convex pattern transfer surface of a cured stamper-receiving layer.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has energy ray curability and has a storage elastic modulus of 10 before curing. ³ -10 ⁶ A stamper-receiving layer which is Pa; A light release sheet having a release layer laminated on one surface of the stamper receiving layer and having a release force of 50 mN / 20 mm or less and a residual adhesion rate of 85% or more, and the stamper; And a heavy release sheet having a release layer laminated on the other surface of the receiving layer and having a peeling force of 70 to 300 mN / 20 mm with respect to the stamper receiving layer and a residual adhesion rate of 85% or more. An optical disc manufacturing sheet is provided (claim 1).
[0009]
[Action]
As a result of intensive studies on the cause of the occurrence of void-like defects on the concavo-convex pattern transfer surface of the cured stamper-receiving layer, the present inventors have found that the residual adhesive rate-decreasing component contained in the release agent layer of the release sheet is transferred to the stamper-receiving layer By doing so, it has been found that such a defect is formed in the stamper-receiving layer during curing. Therefore, according to the optical disk manufacturing sheet of the present invention using the release sheet having a release agent layer having a high residual adhesive rate, that is, a low residual adhesive rate reducing component content, the uneven pattern transfer surface of the cured stamper receiving layer It is possible to prevent the occurrence of void-like defects.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a cross-sectional view of an optical disk manufacturing sheet according to an embodiment of the present invention. FIGS. 2A to 2E are examples of an optical disk manufacturing method using the optical disk manufacturing sheet according to the embodiment. It is sectional drawing shown.
[0011]
As shown in FIG. 1, an optical disk manufacturing sheet 1 according to this embodiment includes a stamper receiving layer 11, a release sheet 12 laminated on one surface (upper surface in FIG. 1) of the stamper receiving layer 11, a stamper receiving The cover sheet 13 is laminated on the other surface of the layer 11 (the lower surface in FIG. 1).
[0012]
The stamper receiving layer 11 is a layer in which a concavo-convex pattern formed on the stamper is transferred to form pits or grooves. The stamper-receiving layer 11 is an energy ray-curable polymer material, preferably an acrylic ester copolymer having an energy ray-curable group in the side chain, and particularly preferably an acrylic material having a functional group-containing monomer unit. Energy ray curable copolymer having a molecular weight of 100,000 or more having an energy ray curable group in the side chain, obtained by reacting a copolymer with an unsaturated group-containing compound having a substituent bonded to the functional group Mainly composed of a combination, and if desired, a photopolymerization initiator, a polymer component or oligomer component that does not have energy ray curability, an energy ray curable polyfunctional monomer or oligomer component, a crosslinking agent, and other additives (ultraviolet absorbers) , Plasticizers, fillers, antioxidants, tackifiers, pigments, dyes, coupling agents, etc.).
[0013]
The storage elastic modulus of the stamper receiving layer 11 before curing is 10 ³ -10 ⁶ Pa, preferably 10 ⁴ ~ 5x10 ⁵ Pa.
[0014]
Here, the measurement temperature of the “storage modulus before curing” is assumed to be the same temperature as the working environment in which the stamper and the optical disc manufacturing sheet 1 are overlaid (compressed). That is, when the stamper and the optical disc manufacturing sheet 1 are overlapped at room temperature, the storage elastic modulus is measured at room temperature, and when the stamper and the optical disc manufacturing sheet 1 are overlapped under heating, the storage elastic modulus is measured. Is measured at the same temperature as the heating temperature.
[0015]
When the storage elastic modulus of the stamper receiving layer 11 before curing is in the above range, the uneven pattern formed on the stamper is precisely transferred to the stamper receiving layer 11 simply by pressing the stamper to the stamper receiving layer 11. As a result, the production of the optical disk becomes extremely simple.
[0016]
The storage elastic modulus of the stamper receiving layer 11 after curing is 10 ⁷ Preferably it is Pa or higher, in particular 10 ⁸ -10 ¹⁰ Pa is preferred. Here, the measurement temperature of the “storage modulus after curing” is the same temperature as the storage environment of the optical disk, that is, room temperature.
[0017]
When the storage elastic modulus of the stamper receiving layer 11 after curing is in the above range, the pits and grooves transferred to the stamper receiving layer 11 are securely fixed by curing, and the stamper and the stamper receiving layer 11 are separated. In this case, there is no possibility that the pits and grooves are destroyed or deformed.
[0018]
The thickness of the stamper-receiving layer 11 is determined according to the depth of the pit or groove to be formed, but is usually about 5 to 100 μm, preferably about 5 to 50 μm.
[0019]
The release sheet 12 includes a base material 121 and a release agent layer 122 formed on the surface of the base material 121 on the side where the stamper-receiving layer 11 is laminated.
[0020]
The base material 121 of the release sheet 12 is not particularly limited, and an arbitrary one can be appropriately selected from those used as the base material in the conventional release sheet. Examples of such a substrate 121 include resin films such as polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyolefin films such as polypropylene and polymethylpentene, polycarbonate films, and polyvinyl acetate films.
[0021]
The thickness of the substrate 121 is not particularly limited, but is usually about 10 to 200 μm, and preferably about 25 to 75 μm.
[0022]
The release agent layer 122 of the release sheet 12 is a layer formed by applying and forming a light release type release agent (hereinafter referred to as “release agent K”), and the release force from the stamper receiving layer 11 is 50 mN / 20 mm or less. It is preferable that it is, and it is especially preferable that it is less than 30 mN / 20mm.
[0023]
The release agent K is mainly composed of a silicone resin or a fluororesin, preferably a silicone resin, and has a residual adhesion rate of 85% or more, preferably 90% or more.
[0024]
Here, the “residual adhesion rate” in the present specification is measured by the following method.
The release agent layer of the release sheet and the adhesive tape (manufactured by Nitto Denko Corporation, product name: polyester adhesive tape 31B) are bonded together, and 9.81 mN / mm ² And left at 70 ° C. for 24 hours, and further left at 23 ° C. and 65% RH for 24 hours, and then the adhesive tape is peeled off and attached to a stainless steel plate. The adhesive tape is peeled off from the stainless steel plate at an angle of 180 ° and a speed of 300 mm / min, and the adhesive force is measured. The adhesive strength measured in this way is expressed as a percentage of the original adhesive strength of the pressure-sensitive adhesive tape that is not in contact with the release sheet, and is defined as the residual adhesive rate.
[0025]
In the present invention, when a release sheet having a residual adhesion rate of less than 85% is used, it has been found that void-like defects are formed on the concavo-convex pattern transfer surface of the stamper-receiving layer during curing. That is, when using a release sheet that does not contain a component that greatly reduces the residual adhesion rate in the release agent layer, it is possible to prevent the occurrence of void-like defects on the concavo-convex pattern transfer surface of the cured stamper receiving layer. it can.
[0026]
Examples of the component that lowers the residual adhesion rate include a silicone-based low molecular weight component that is added to the main agent in order to adjust the release characteristics of the release sheet. When a silicone release agent is used as the release agent, there is a possibility that an unreacted monomer of a silicone polymer polymerized as a main agent or an oligomer having a low polymerization degree affects the occurrence of void-like defects.
[0027]
However, since the silicone-based release agent has a lower release force than other release agents, it is difficult to damage the stamper-receiving layer with deformation when it is released. Also from the viewpoint of the condition of the peeling speed, the release sheet using the silicone-based release agent can obtain stable characteristics with a low peeling force widely from low speed to high speed. For this reason, even if it is a case where the manufacturing process of an optical disk is automated, according to the peeling sheet using a silicone type release agent, the capability of a manufacturing apparatus is not restrict | limited and manufacturing efficiency can be improved.
[0028]
Therefore, the release agent K is preferably selected from silicone release agents. As the silicone release agent, an addition reaction type silicone resin composition containing an addition reaction type silicone resin and a crosslinking agent, and optionally a catalyst, a photosensitizer, an addition reaction inhibitor, an adhesion improver and the like is used. Is preferred.
[0029]
By selecting an addition reaction type silicone resin as the silicone resin, a light release type release agent can be obtained without reducing the residual adhesion rate. The addition reaction type silicone resin is particularly preferably a photocurable silicone resin that is cured by heat treatment and ultraviolet irradiation treatment.
[0030]
As such a photocurable silicone resin, polyorganosiloxane having an alkenyl group as a functional group in the molecule is preferable. Examples of the alkenyl group include a vinyl group, an allyl group, a methacryl group, a hexenyl group, a butadienyl group, A hexadienyl group, a cyclopentenyl group, a cyclopentazinyl group, a cyclohexenyl group and the like can be mentioned, and a vinyl group and an allyl group are particularly preferred.
[0031]
Examples of the crosslinking agent include polyorganosiloxane having at least two silicon-bonded hydrogen atoms in one molecule, specifically, a dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethyl. Examples thereof include silicone resins such as siloxy group-end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group-end-capped poly (methylhydrogensiloxane), and poly (hydrogensilsesquioxane). The usage-amount of a crosslinking agent is 0.1-100 weight part normally with respect to 100 weight part of addition reaction type silicone resins, Preferably it is 0.3-50 weight part.
[0032]
As the catalyst, a platinum compound is usually used. Examples of the platinum compound include fine platinum, fine platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid olefin complex, palladium, rhodium catalyst, and the like. . The usage-amount of a catalyst is about 1-1000 ppm as a metal with respect to the total amount of an addition reaction type silicone resin and a crosslinking agent.
[0033]
There is no restriction | limiting in particular as a photosensitizer, From what is normally used for ultraviolet curable resin, arbitrary things can be suitably selected and used. Examples of the photosensitizer include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether, benzophenones, benzophenones such as 4,4′-dimethylaminobenzophenone, 2,4,6-trimethylbenzophenone, acetophenone, Acetophenones such as N, N-dimethylaminoacetophenone and propiophenone, (1-hydroxy) cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, oligo {2-hydroxy-2- Α-hydroxyketones such as methyl-1- [4- (1-propenyl) phenyl] propanone}, 2-methyl-1- [4- (methylthio) phenyl-2-morpholinopropan-1-one, 2-benzyl -2-dimethylamino-1- (4- Α-aminoketones such as ruphorinophenyl) butan-1-one, α-diketones such as benzyl, α-diketone dialkylacetals such as benzyldimethylacetal, anthraquinones such as 2-aminoanthraquinone, 2,4-dimethylthioxanthone, etc. Thioxanthones, tertiary amines such as ethyl 4-dimethylaminobenzoate, and azo compounds such as α, α′-azobisisobutyronitrile.
[0034]
These photosensitizers may be used alone or in combination of two or more. The amount used is usually selected in the range of 0.01 to 30 parts by weight, preferably 0.05 to 20 parts by weight with respect to 100 parts by weight of the total amount of the addition reaction type silicone resin and the crosslinking agent.
[0035]
The addition reaction inhibitor is a component used for imparting storage stability at room temperature to the addition reaction type silicone resin composition. As a specific example, 3,5-dimethyl-1-hexyne-3-ol is used. , 3-methyl-1-penten-3-ol, 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne, cyclic tetravinylsiloxane, benzotriazole, etc. It is done.
[0036]
In order to form the release agent layer 122 on the substrate 121, first, each component of the release agent K is blended at a predetermined ratio to prepare a coating liquid having a coatable viscosity. There is no restriction | limiting in particular as an organic solvent used at this time, A various thing can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, ethyl acetate, methyl ethyl ketone, and mixtures thereof are used.
[0037]
The coating solution thus prepared is applied to the surface of the substrate 121 by, for example, a gravure coating method, a bar coating method, a spray coating method, or the like. The coating amount in terms of solid content is usually 0.01 to 3.0 g / m. ² , Preferably 0.02 to 1.5 g / m ² It adjusts suitably so that it may become.
[0038]
When the release agent K is mainly composed of a photo-curable silicone resin, the substrate 121 coated with the coating liquid as described above is first pre-cured by heat treatment and then completely cured by ultraviolet irradiation. It is preferable to do so. The heating temperature for the pre-curing is preferably 40 to 120 ° C, and particularly preferably 50 to 100 ° C.
[0039]
In ultraviolet irradiation, for example, an ultraviolet lamp such as a high-pressure mercury lamp, a metal halide lamp, a high-power metal halide lamp, or an electrodeless ultraviolet lamp can be used. It is preferable to use an electrodeless ultraviolet lamp because it is less and the curability of the silicone resin is good.
[0040]
The ultraviolet irradiation output is usually 30 to 600 W / cm, preferably 50 to 360 W / cm. The temperature at the time of the ultraviolet irradiation treatment is not particularly limited, and may be any of a heated state immediately after the heat treatment or a room temperature state as long as the ultraviolet irradiation treatment is performed in-line.
[0041]
In addition, when the uneven | corrugated pattern of a stamper is transcribe | transferred to the surface by which the release sheet 12 is laminated | stacked in the stamper receiving layer 11, the surface of the release agent layer 122 of the release sheet 12 makes the stamper receiving layer 11 smooth. In order to give, it is preferable that surface roughness (Ra) is 0.1 micrometer or less.
[0042]
The cover sheet 13 in the present embodiment constitutes a part of the optical disk such as a light receiving surface and a label surface of the optical disk. As the material of the cover sheet 13, in the case where the cover sheet 13 constitutes a light receiving surface, any material may be used as long as it has sufficient light transmittance with respect to the wavelength range of light for reading information. In the case of constituting the surface, those having an easily adhesive surface on which the ink for label printing is easily fixed are preferable. In any case, the material of the cover sheet 13 is preferably a material having moderate rigidity and flexibility in order to easily manufacture the optical disk, and stable with respect to temperature for storing the optical disk. Preferably there is. As such a material, for example, a resin such as polycarbonate, polymethyl methacrylate, or polystyrene can be used.
[0043]
The linear expansion coefficient of the cover sheet 13 is preferably substantially the same as the linear expansion coefficient of the optical disk substrate so that the optical disk does not warp at high temperatures. For example, when the optical disk substrate is made of polycarbonate resin, the cover sheet 13 is preferably made of the same polycarbonate resin.
[0044]
The thickness of the cover sheet 13 is determined according to the type of the optical disk and the thickness of other components of the optical disk, but is usually about 25 to 300 μm, and preferably about 50 to 200 μm.
[0045]
The optical disk manufacturing sheet 1 according to the present embodiment is prepared by preparing a coating agent containing a material constituting the stamper-receiving layer 11 and, if desired, a solvent, a kiss roll coater, a reverse roll coater, a knife coater, and a roll knife coater. The stamper receiving layer 11 is formed by coating on the cover sheet 13 with a coating machine such as a die coater, and then the release sheet 12 is laminated on the surface of the stamper receiving layer 11, or the coating described above. An agent is applied onto the release sheet 12 and dried to form the stamper-receiving layer 11, and then the cover sheet 13 is laminated on the surface of the stamper-receiving layer 11.
[0046]
Next, an example of an optical disk manufacturing method using the optical disk manufacturing sheet 1 will be described.
[0047]
First, as shown in FIG. 2A, the release sheet 12 of the optical disk manufacturing sheet 1 is peeled off to expose the stamper receiving layer 11.
[0048]
Next, as shown in FIGS. 2A to 2B, the stamper S is pressure-bonded to the exposed surface of the stamper receiving layer 11, and the uneven pattern of the stamper S is transferred to the stamper receiving layer 11.
[0049]
Then, as shown in FIG. 2 (b), with the stamper S in close contact with the stamper receiving layer 11, an energy ray irradiation device (in FIG. 2 (b), as an example, a UV lamp L) is used to cover the cover. The stamper receiving layer 11 is irradiated with energy rays from the sheet 13 side. Thereby, the stamper receiving layer 11 is hardened and the storage elastic modulus is increased.
[0050]
Thereafter, as shown in FIG. 2C, the stamper S is separated from the stamper receiving layer 11. In this way, the concave / convex pattern of the stamper S is transferred and fixed to the stamper receiving layer 11 to form pits or grooves. However, in the optical disk manufacturing sheet 1 of this embodiment, the residual adhesive rate is 85% or more. Since the release sheet 12 having the layer 122 is used, it is possible to prevent the residual adhesive rate lowering component of the release layer 122 from moving to the stamper receiving layer 11 and forming void-like defects on the uneven pattern transfer surface. .
[0051]
Next, as shown in FIG. 2D, the reflective film 4 is formed on the surface of the stamper receiving layer 11 by means such as sputtering. The reflective film 4 may be a multilayer film further including a recording layer such as a phase change recording layer.
[0052]
Then, as shown in FIG. 2 (e), an optical disk substrate 3 is laminated on the reflective film 4 with an adhesive 5 to obtain an optical disk.
[0053]
The optical disk manufacturing sheet of the present invention may have a laminated structure in which a cover sheet is not laminated, and release sheets are laminated on both sides of the stamper-receiving layer. FIG. 3 shows a cross-sectional view of the optical disc manufacturing sheet 1 ′ having such a configuration.
[0054]
In this optical disk manufacturing sheet 1 ′, the same release sheet 12 as the release sheet 12 of the optical disk manufacturing sheet 1 is formed on one surface of the stamper receiving layer 11 so that the respective release sheets can be smoothly and smoothly released. (Light release type) A heavy release sheet 12 ′ having a high release force is laminated on the other surface of the stamper-receiving layer 11.
[0055]
Similarly to the release sheet 12, the heavy release sheet 12 ′ is composed of a base material 121 ′ and a release agent layer 122 ′ formed on the surface of the base material 121 ′ on which the stamper-receiving layer 11 is laminated. The base material 121 ′ of the heavy release sheet 12 ′ can be selected from the same material as the base material 121 of the release sheet 12 described above. The thickness of the substrate 121 ′ is usually about 10 to 200 μm, preferably about 25 to 75 μm.
[0056]
The release agent layer 122 ′ of the heavy release sheet 13 is a layer formed by applying and forming a heavy release type release agent (hereinafter referred to as “release agent J”), and its release force is 70 to 300 mN / 20 mm. Is preferable, and 80 to 150 mN / 20 mm is particularly preferable.
[0057]
The release agent J, like the release agent K, preferably has a residual adhesive rate of 85% or more, particularly 90% or more. Examples of the component of the release agent J include a silicone resin, a fluororesin, an alkyd resin, and a long-chain alkyl resin. Preferably, the silicone resin is the main component. Since a general heavy release silicone resin tends to exhibit a high residual adhesion rate, it can often be used as the release agent J without any particular adjustment. Moreover, even if it is a release agent composition used as the release agent K mentioned above, if a mixing | blending is adjusted so that the said peeling force may be obtained, it can be used as the release agent J.
[0058]
The heavy release sheet 12 ′ can be produced by the same method as that for the light release sheet 12 described above. The coating amount in terms of solid content of the release agent layer 122 ′ is usually 0.01 to 3.0 g / m. ² , Preferably 0.02 to 1.5 g / m ² It adjusts suitably so that it may become.
[0059]
In order to manufacture the optical disk manufacturing sheet 1 ′ according to the present embodiment, a coating liquid of a material constituting the stamper receiving layer 11 is prepared, and one of the peelings is performed by, for example, a gravure coating method, a bar coating method, a spray coating method, After coating on the release agent layer of the sheet (release sheet 12 or heavy release sheet 12 ′) and drying to form the stamper receiving layer 11, the other release sheet (heavy release sheet) is formed on the surface of the stamper receiving layer 11. The release sheet may be laminated so that the release agent layer of 12 'or release sheet 12) contacts.
[0060]
The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
[0061]
【Example】
EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.
[0062]
[Example 1]
(Manufacture of light release sheet)
Addition reaction type silicone resin release agent (trade name: SRX-211, manufactured by Toray Dow Corning Silicone Co., Ltd.), which is mainly composed of polydimethylsiloxane having a vinyl group as a functional group and polymethylhydrogensiloxane as a crosslinking agent. 2 parts by weight of platinum-based catalyst (trade name: SRX-212, manufactured by Toray Dow Corning Silicone Co., Ltd.) is added to parts by weight, and α-diketone dialkyl acetal as a photosensitizer per 100 parts by weight of the main component. 0.1 part by weight of benzyl dimethyl acetal was added and diluted with an organic solvent mainly composed of toluene to prepare a coating solution of a release agent having a solid content concentration of 1% by weight.
[0063]
This coating solution is applied on a polyethylene terephthalate film (thickness: 38 μm) as a base material so that the coating amount in terms of solid content is 0.13 g / m. ² It was uniformly coated by a gravure coating method. Next, after heat treatment for 20 seconds in a hot air circulation dryer at 50 ° C., immediately a conveyor type electrodeless UV irradiation machine with a H bulb 240 W / cm1 lamp attached by Fusion (uses a high diffusion type heat filter) ), The release agent was cured by irradiating ultraviolet rays at a conveyor speed of 200 m / min, and a light release sheet was produced.
[0064]
The obtained light release sheet had a residual adhesion rate of 90%, and the release agent layer had a surface roughness (Ra) of 0.024 μm.
[0065]
(Manufacture of optical disc manufacturing sheets)
62 parts by weight of butyl acrylate, 10 parts by weight of methyl methacrylate, and 28 parts by weight of 2-hydroxyethyl acrylate are reacted in ethyl acetate to obtain an ethyl acetate solution of an acrylic copolymer having a hydroxyl group as a functional group (solid A partial concentration of 40% by weight). Furthermore, 250 parts by weight of an ethyl acetate solution of the acrylic copolymer, 100 parts by weight of ethyl acetate, and 30 parts by weight of methacryloyloxyethyl isocyanate as an unsaturated group-containing compound having an isocyanate group as a substituent (acrylic type) 80.5 equivalents of 100 equivalents of 2-hydroxyethyl acrylate of the copolymer) and 0.12 parts by weight of dibutyltin dilaurate as a catalyst are added and reacted at room temperature in a nitrogen atmosphere for 24 hours. A curable copolymer was obtained. The energy ray curable copolymer had a weight average molecular weight (Mw) of 600,000.
[0066]
To 100 parts by weight of the solid content of the obtained energy beam curable copolymer, 3.7 weight of 1-hydroxycyclohexyl phenyl ketone (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) as a photopolymerization initiator. The solid part concentration was adjusted to 35% by weight to prepare a coating agent for the stamper-receiving layer.
[0067]
The obtained coating agent for the stamper-receiving layer was applied onto the release agent layer of the light release sheet with a knife coater and dried at 90 ° C. for 1 minute to form a stamper-receiving layer having a thickness of 20 μm. A cover sheet made of a polycarbonate film (trade name: Pure Ace C110-80, thickness: 80 μm) was laminated on the surface of the stamper-receiving layer, and this was used as an optical disk manufacturing sheet.
[0068]
In the obtained optical disc production sheet, the peel force between the light release sheet and the stamper-receiving layer was 43 mN / 20 mm. Further, the storage elastic modulus of the stamper-receiving layer before curing was measured at 25 ° C. at 1 Hz using a viscoelasticity measuring apparatus (manufactured by Rheometrics, apparatus name: DYNAMIC ANALYZER RDA II). The rate is 1.4 × 10 ⁴ Pa.
[0069]
The light release sheet of the optical disk production sheet was peeled off, and the stamper was pressure-bonded to the exposed surface of the stamper receiving layer with a pressure of 29N. The stamper-receiving layer was irradiated with ultraviolet rays from the cover sheet side (Lintech Co., Ltd., apparatus name: Adwill RAD-2000 m / 8, irradiation condition: illuminance: 310 mW / cm ² , Light quantity 300mJ / cm ² ), The stamper-receiving layer was cured.
[0070]
When the storage elastic modulus of the stamper-receiving layer after curing was measured at 25 ° C. at 3.5 Hz using a viscoelasticity measuring device (Orientec Co., Ltd., device name: Leopybron DDV-II-EP), it was cured. Later storage modulus is 6.0 × 10 ⁸ Pa.
[0071]
The cured stamper receiving layer and the stamper are separated, and the uneven pattern transfer surface of the stamper receiving layer is observed with an atomic force microscope (manufactured by Seiko Instruments Inc., apparatus name: SPI3800N / SPA300HV) at a scan size of 2 μm × 2 μm. The number of void defects on the surface of the stamper receiving layer was confirmed. The results are shown in Table 1.
[0072]
[Example 2]
In Example 1, instead of the cover sheet, a heavy release sheet based on a polyethylene terephthalate film having a thickness of 38 μm (manufactured by Lintec, trade name: SP-PET3811, residual adhesive rate: 85%, surface roughness of the release agent layer) (Ra): 0.029 μm) was laminated on the stamper-receiving layer, and the other processes were performed in the same manner as in Example 1 to manufacture a sheet for manufacturing an optical disk having release sheets on both sides of the stamper-receiving layer.
[0073]
In the obtained optical disk manufacturing sheet, the peel force between the heavy release sheet and the stamper-receiving layer was 88 mN / 20 mm.
[0074]
The light release sheet of the optical disk production sheet was peeled off, and the exposed surface of the stamper-receiving layer was pressure bonded to an optical disk substrate (thickness: 1.1 mm, outer diameter 120 mm) made of polycarbonate. Subsequently, the heavy release sheet was peeled off, and the stamper was pressure-bonded to the exposed surface of the stamper receiving layer with a pressure of 29 N. Then, the optical disk substrate was irradiated with ultraviolet rays in the same manner as in Example 1 to cure the stamper receiving layer. .
[0075]
The cured stamper-receiving layer and the stamper were separated and the number of void-like defects on the surface of the stamper-receiving layer was confirmed by observing a scan size of 2 μm × 2 μm with an atomic force microscope on the uneven pattern transfer surface of the stamper-receiving layer. The results are shown in Table 1.
[0076]
[Comparative Example 1]
In Example 1, 100 parts by weight of a curable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KS847H) and a curing agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: PL50T) were used. Example) Except for adjusting to a 1% solid content solution containing 1.0 part by weight and 2.5 parts by weight of dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF96H-1 million cs) In the same manner as in No. 1, a light release sheet and a sheet for producing an optical disc were produced. The residual release rate of this light release sheet was 78%, the surface roughness (Ra) of the release agent surface was 0.028 μm, and the release force from the stamper-receiving layer was 35 mN / 20 mm.
[0077]
Next, in the same manner as in Example 1, the stamper was pressed and irradiated with ultraviolet rays, and the number of void defects on the surface of the stamper-receiving layer was confirmed. The results are shown in Table 1.
[0078]
[Comparative Example 2]
In Example 1, 100 parts by weight of a curable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KS847H) and a curing agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: PL50T) were used. The same as in Example 1 except that the solution was adjusted to a solid content concentration of 1% containing 1.0 part by weight and 0.30 part by weight of methyl phenyl silicone oil (trade name: KF54, manufactured by Shin-Etsu Chemical Co., Ltd.) Thus, a light release sheet and a sheet for producing an optical disc were produced. The residual release rate of this light release sheet was 76%, the surface roughness (Ra) of the release agent surface was 0.030 μm, and the release force from the stamper-receiving layer was 30 mN / 20 mm.
[0079]
Next, in the same manner as in Example 1, the stamper was pressed and irradiated with ultraviolet rays, and the number of void defects on the surface of the stamper-receiving layer was confirmed. The results are shown in Table 1.
[0080]
[Table 1]

[0081]
As is apparent from Table 1, in the optical disc production sheet using the light release sheet produced in Examples 1 and 2, no void-like defects were found on the concavo-convex pattern transfer surface of the photocured stamper receiving layer. In the optical disc production sheet using the light release sheet produced in Comparative Examples 1 and 2, a void-like defect was observed on the concavo-convex pattern transfer surface of the photocured stamper receiving layer.
[0082]
【The invention's effect】
According to the present invention, it is possible to prevent a void-like defect from occurring on the concavo-convex pattern transfer surface of the cured stamper-receiving layer.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an optical disk manufacturing sheet according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an example of an optical disk manufacturing method using the optical disk manufacturing sheet according to the embodiment.
FIG. 3 is a cross-sectional view of an optical disc manufacturing sheet according to another embodiment of the present invention.
[Explanation of symbols]
1, 1 '... Optical disc manufacturing sheet
11 ... Stamper receiving layer
12, 12 '... release sheet
121, 121 '... base material
122, 122 '... release agent layer
13 ... Cover sheet

Claims (1)

A stamper-receiving layer having energy ray curability and a storage elastic modulus before curing of 10 ³ to 10 ⁶ Pa;
A light release sheet having a release layer laminated on one surface of the stamper receiving layer, having a release force of 50 mN / 20 mm or less and a residual adhesion rate of 85% or more with the stamper receiving layer;
A heavy release sheet having a release layer laminated on the other surface of the stamper receiving layer and having a release force of 70 to 300 mN / 20 mm with respect to the stamper receiving layer and a residual adhesion rate of 85% or more;
Sheet for an optical disk manufacturing, characterized in that it comprises a.

Images