JP4587944B2 - Energy ray curable resin composition for stamper-receiving layer, sheet for producing optical recording medium, and optical recording medium - Google Patents

Description

  The present invention relates to an energy ray-curable resin composition for forming a stamper-receiving layer in an optical recording medium, an optical recording medium production sheet capable of producing an optical recording medium, and an optical recording medium.

  As a method of manufacturing an optical disk, an optical disk manufacturing sheet provided with a stamper receiving layer is used. After a stamper receiving layer is laminated on an optical disk substrate, an uneven pattern of the stamper is transferred and fixed to the stamper receiving layer, and then the stamper receiving layer A method has been proposed in which a reflective film (information recording layer) is formed thereon and a protective sheet is laminated on the reflective film to form an optical disc (Patent Document 1).

Examples of the material constituting the stamper-receiving layer include an acrylate copolymer having an energy ray-curable group in the side chain, a photopolymerization initiator, a polymer component or an oligomer component having no energy ray curability, and an energy ray curable property. Those containing a polyfunctional monomer or oligomer component, a crosslinking agent, and the like.
JP 2003-123332 A

  However, the above-mentioned stamper-receiving layer may not always have sufficient adhesion to the reflective film of the optical disc depending on the type of acrylic ester copolymer. The reflective film is usually formed on the concavo-convex pattern of the optical disk substrate formed by a method such as injection molding or on the stamper receiving layer to which the concavo-convex shape of the stamper is transferred, but the adhesion between the stamper receiving layer and the reflective film If this is not sufficient, the stamper-receiving layer and the reflective film may be separated during the optical disk manufacturing process, or the completed optical disk may be peeled off between layers depending on storage conditions. In addition, when the adhesive strength of the stamper receiving layer to the reflective film is lower than the adhesive strength to the stamper, there arises a problem that when the stamper is separated from the stamper receiving layer, the stamper receiving layer is peeled off from the reflective layer.

  The present invention has been made in view of the above circumstances, and is an energy ray curable resin that is excellent in adhesion to a reflective film or an information recording layer and can form a stamper-receiving layer having low adhesion to a stamper. It is an object of the present invention to provide a composition, a sheet for producing an optical recording medium provided with such a stamper-receiving layer, and an optical recording medium excellent in adhesion between the stamper-receiving layer and a reflective film or an information recording layer.

（式中、Ｒ_１は水素またはメチル基であり、ｎは０〜５の整数である。）
で表される化合物とを含有し、前記エネルギー線硬化性樹脂組成物中における前記一般式（１）で表される化合物の含有量は、０．１〜１０質量％であることを特徴とするスタンパー受容層用エネルギー線硬化性樹脂組成物を提供する（請求項１）。 In order to achieve the above object, first, the present invention provides a stamper in which an uneven pattern of a stamper formed of nickel, which is laminated on a reflective film formed of silver, a silver alloy or aluminum in an optical recording medium , is transferred. An energy ray curable resin composition for forming a receiving layer,
Polymer-containing energy ray-curable component and the following general formula (1)

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 0 to 5.)
And the content of the compound represented by the general formula (1) in the energy ray curable resin composition is 0.1 to 10% by mass. An energy ray-curable resin composition for a stamper-receiving layer is provided (claim 1).

  Note that. An “optical recording medium” in this specification refers to a medium on which information can be optically recorded / reproduced, and is mainly a read-only, write once or rewritable disc-like medium (for example, CD, CD- ROM, CD-R, CD-RW, DVD, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, LD, Blu-ray Disc, HD DVD, MO, etc .; so-called optical disks (including magneto-optical disks) ), But is not necessarily limited to these.

  While the stamper-receiving layer by the energy ray-curable resin composition according to the invention (invention 1) is excellent in adhesion to the reflective film or the information recording layer due to the presence of the compound represented by the general formula (1), The adhesive strength to the stamper is low. Note that the “reflective film” in this specification is a film that reflects all or part of the laser light, and includes a translucent film.

  In the above invention (Invention 1), the polymer-containing energy ray-curable component is mainly composed of a polymer having energy ray-curability (Invention 2), or a polymer not having energy ray-curability and an energy ray. A mixture of a curable polyfunctional monomer and / or oligomer is preferred as a main component (claim 4). In the former case, the polymer-containing energy ray-curable component preferably further contains an energy ray-curable monomer and / or oligomer (claim 3).

  In the said invention (invention 1-4), it is preferable that each component contained in the said polymer containing energy ray hardening component does not contain an acidic functional group substantially (invention 5).

  By not containing, for example, a carboxyl group as an acidic functional group, it is possible to prevent corrosion of the reflective film and yellowing of the stamper-receiving layer due to the carboxyl group. However, the adhesive force to the reflective film or the information recording layer is ensured by the compound represented by the general formula (1).

Secondly, the present invention relates to an optical recording medium comprising a stamper-receiving layer which is laminated on a reflective film formed of silver, a silver alloy or aluminum in an optical recording medium and onto which a concave / convex pattern of a stamper formed of nickel is transferred. A manufacturing sheet, wherein the stamper-receiving layer comprises the energy ray-curable resin composition (Claims 1 to 5) (Claim 6).

Thirdly, the present invention provides an optical recording medium manufactured using the sheet for manufacturing an optical recording medium (Claim 6), a reflective film formed of silver, a silver alloy or aluminum, and the reflective film And a stamper-receptive layer to which the concave / convex pattern of the stamper formed of nickel is transferred. The optical recording medium is provided (claim 7).

  According to the energy ray curable resin composition of the present invention, it is possible to form a stamper-receiving layer that is excellent in adhesiveness to a reflective film or an information recording layer, but has low adhesion to a stamper. Further, according to the sheet for producing an optical recording medium of the present invention, it is possible to form a stamper receiving layer excellent in adhesiveness with a reflective film or an information recording layer, and when separating the stamper from the stamper receiving layer, It is possible to prevent the stamper receiving layer from being peeled off from the reflective film or the information recording layer. Furthermore, the optical recording medium of the present invention is excellent in the adhesion between the stamper-receiving layer and the reflective film or the information recording layer, and delamination does not easily occur during product storage.

（式中、Ｒ_１は水素またはメチル基であり、ｎは０〜５の整数である。）
で表される化合物（以下「化合物（II）」という場合がある。）と
を含有する。 Hereinafter, embodiments of the present invention will be described.
[Energy ray curable resin composition]
The energy ray curable resin composition for a stamper-receiving layer according to this embodiment is
(I) a polymer-containing energy ray-curable component;
(II) The following general formula (1)

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 0 to 5.)
(Hereinafter sometimes referred to as “compound (II)”).

I. Polymer-containing energy beam curable component The polymer-containing energy beam curable component (I) may be composed mainly of a polymer having energy beam curable properties, or a polymer having no energy beam curable properties and an energy beam curable multifunctional. It is good also considering the mixture with a monomer and / or an oligomer as a main component.

  The case where the polymer-containing energy beam curable component (I) is mainly composed of a polymer having energy beam curable properties will be described below.

  The polymer having energy ray curability is a (meth) acrylic acid ester (co) polymer (A) (hereinafter referred to as “energy ray”) in which a functional group having energy ray curability (energy ray curable group) is introduced into the side chain. It may be referred to as “curable polymer (A)”). This energy ray curable polymer (A) includes a (meth) acrylic copolymer (a1) having a functional group-containing monomer unit, and an unsaturated group-containing compound (a2) having a substituent bonded to the functional group. It is preferable that it is obtained by making it react. In the present specification, “(meth) acrylic acid ester” means acrylic acid ester and / or methacrylic acid ester, and “(co) polymer” means polymer and / or copolymer. It shall be.

  Here, the average side chain introduction rate of the energy ray-curable group is preferably 0.1 to 30 mol%. When the average side chain introduction rate of the energy ray curable group is less than 0.1 mol%, the desired energy ray curable property cannot be obtained, and when the average side chain introduction rate of the energy ray curable group exceeds 30 mol%, The optical recording medium may be warped due to volume shrinkage accompanying the curing of the stamper-receiving layer.

In addition, the average side chain introduction rate of the energy ray curable group is calculated by the following formula.
Average side chain introduction rate of energy beam curable group = (number of moles of energy beam curable group / total number of moles of monomers constituting acrylic copolymer) × 100

  The acrylic copolymer (a1) is composed of a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth) acrylic acid ester monomer or a derivative thereof.

  The functional group-containing monomer as a constituent unit of the acrylic copolymer (a1) is a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, an amino group, a substituted amino group, or an epoxy group in the molecule. In particular, a hydroxyl group-containing unsaturated compound is preferably used.

  In addition, it is preferable that a functional group containing monomer is a thing which does not have an acidic functional group, for example, a carboxyl group. In the case of a functional group-containing monomer having a carboxyl group, sufficient adhesion to a reflective film or an information recording layer can be obtained, but an unsaturated group having a substituent (for example, an isocyanate group or an epoxy group) bonded to the carboxyl group. Since the reactivity with the containing compound (a2) is low, it is difficult to introduce the energy ray-curable group into the side chain of the (meth) acrylic acid ester (co) polymer at a high introduction rate. Further, depending on the composition of the energy beam curable resin composition or the use conditions of the optical recording medium, the reflective film may be corroded or the stamper-receiving layer may turn yellow.

  Even if the functional group-containing monomer does not contain a carboxyl group, the energy ray-curable resin composition according to this embodiment has sufficient adhesion to the reflective film or the information recording layer due to the presence of the compound (II) described later. Can be secured.

  More specific examples of the functional group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

  Examples of the (meth) acrylic acid ester monomer constituting the acrylic copolymer (a1) include cycloalkyl (meth) acrylate, benzyl (meth) acrylate, and alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms. Is used. Among these, alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group are particularly preferable, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and n-butyl (meth) acrylate. 2-ethylhexyl (meth) acrylate or the like is used.

  The acrylic copolymer (a1) usually contains 3 to 100% by mass, preferably 5 to 40% by mass, particularly preferably 10 to 30% by mass of the structural unit derived from the functional group-containing monomer, A structural unit derived from a (meth) acrylic acid ester monomer or a derivative thereof is usually contained in an amount of 0 to 97% by mass, preferably 60 to 95% by mass, particularly preferably 70 to 90% by mass.

  The acrylic copolymer (a1) can be obtained by copolymerizing a functional group-containing monomer as described above with a (meth) acrylic acid ester monomer or a derivative thereof in a conventional manner. Dimethylacrylamide, vinyl formate, vinyl acetate, styrene and the like may be copolymerized in a small amount (for example, 10% by mass or less, preferably 5% by mass or less).

  By reacting the acrylic copolymer (a1) having the functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a substituent bonded to the functional group, an energy beam curable polymer (A ) Is obtained.

  The substituent which an unsaturated group containing compound (a2) has can be suitably selected according to the kind of functional group of the functional group containing monomer unit which an acrylic copolymer (a1) has. For example, when the functional group is a hydroxyl group, an amino group or a substituted amino group, the substituent is preferably an isocyanate group or an epoxy group, and when the functional group is an epoxy group, the substituent is an amino group, a carboxyl group or an aziridinyl group. preferable. One such substituent is included in each molecule of the unsaturated group-containing compound (a2).

The unsaturated group-containing compound (a2) contains 1 to 5, preferably 1 to 2, energy-polymerizable carbon-carbon double bonds per molecule.
Specific examples of such unsaturated group-containing compound (a2) include, for example, 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1- ( Bisacryloyloxymethyl) ethyl isocyanate; acryloyl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth) acrylate; diisocyanate compound or polyisocyanate compound, polyol compound, and hydroxyethyl (meth) Acryloyl monoisocyanate compound obtained by reaction with acrylate; glycidyl (meth) acrylate; (meth) acrylic acid, 2- (1 -Aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline and the like.

  The unsaturated group-containing compound (a2) is usually 10 to 100 equivalents, preferably 20 to 95 equivalents, particularly preferably 25 to 90 equivalents per 100 equivalents of the functional group-containing monomer of the acrylic copolymer (a1). Used in

  In the reaction between the acrylic copolymer (a1) and the unsaturated group-containing compound (a2), depending on the combination of the functional group and the substituent, the reaction temperature, pressure, solvent, time, presence of catalyst, catalyst Can be selected as appropriate. As a result, the functional group present in the acrylic copolymer (a1) reacts with the substituent in the unsaturated group-containing compound (a2), so that the unsaturated group is contained in the acrylic copolymer (a1). It introduce | transduces into a side chain and an energy-beam curable polymer (A) is obtained.

  The reaction rate between the functional group and the substituent in this reaction is usually 50% or more, preferably 80% or more, and an unreacted functional group may remain in the energy ray-curable polymer (A). . However, it is preferable that an acidic functional group, for example, a carboxyl group does not remain in the energy ray curable polymer (A) as an unreacted functional group.

  The weight average molecular weight of the energy ray curable polymer (A) thus obtained is preferably 10,000 or more, particularly preferably 150,000 to 1,500,000, and more preferably 200,000 000 to 1,000,000 is preferred. In addition, the weight average molecular weight (Mw) in this specification is the value of polystyrene conversion measured by the gel permeation chromatography method (GPC method).

  The content of the energy beam curable polymer (A) in the energy beam curable resin composition is preferably 20 to 99.9% by mass, and particularly preferably 30 to 80% by mass. If the content of the energy ray curable polymer (A) is less than 20% by mass, it is difficult to obtain good uneven pattern transferability, and the content of the (meth) acrylic acid ester (co) polymer (A) is small. If it exceeds 99.9% by mass, the content of the compound (II) is relatively decreased, and the effect of the compound (II) is hardly obtained.

  Even when the polymer-containing energy beam curable component (I) is mainly composed of a polymer having energy beam curable properties, the polymer-containing energy beam curable component (I) is an energy beam curable monomer and / or Or it is preferable to contain an oligomer (B) further. By containing this energy ray-curable monomer and / or oligomer (B), the conformability of the stamper to the concavo-convex pattern is improved, the shape transferability of the concavo-convex pattern is improved, or the cured stamper-receiving layer The elastic modulus can be increased, and the retention of the transferred shape is improved.

  As the energy ray-curable monomer and / or oligomer (B), for example, an ester of a polyhydric alcohol and (meth) acrylic acid or the like can be used. However, for the same reason as described above, an acid functional group such as a carboxyl group is preferably substantially not included.

  Examples of the energy ray-curable monomer and / or oligomer (B) include monofunctional acrylic acid esters such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, penta Erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol Polyfunctional acrylic acid esters such as di (meth) acrylate and dimethyloltricyclodecane di (meth) acrylate, polyester oligo (meth) acrylate, polyurethane oligo (meth) Acrylate, and the like.

  When the energy ray curable monomer and / or oligomer (B) is blended, the content of the energy ray curable monomer and / or oligomer (B) in the energy ray curable resin composition is 5 to 80% by mass. It is preferable that it is especially 20-60 mass%.

  Here, when using ultraviolet rays as an energy ray for curing the energy ray curable resin composition, it is preferable to add a photopolymerization initiator (C), and by using this photopolymerization initiator (C). The polymerization curing time and the amount of light irradiation can be reduced.

  Specific examples of the photopolymerization initiator (C) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, (2,4 6-trimethylbenzyldiphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy-2-methyl 1- [4- (1-propenyl) phenyl] propanone}, and 2,2-dimethoxy-1,2-and the like. These may be used alone or in combination of two or more.

  The photopolymerization initiator (C) is energy beam curable copolymer (A) (when energy beam curable monomer and / or oligomer (B) is blended, energy beam curable copolymer (A). And a total amount of 100 parts by mass of the energy ray-curable monomer and / or oligomer (B)) used in an amount in the range of 0.1 to 10 parts by mass, particularly 0.5 to 6 parts by mass. It is preferred that

  In the polymer-containing energy ray curable component (I), other components may be appropriately blended in addition to the above components. Examples of other components include a polymer component or oligomer component (D) that does not have energy beam curability, and a crosslinking agent (E).

  Examples of the polymer component or oligomer component (D) having no energy beam curability include polyacrylates, polyesters, polyurethanes, polycarbonates, polyolefins, and the like, and the weight average molecular weight (Mw) is 3,000 to 2, 500,000 polymers or oligomers are preferred.

  As a crosslinking agent (E), the polyfunctional compound which has the reactivity with the functional group which an energy-beam curable copolymer (A) etc. have can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts. And reactive phenol resins.

  By blending these other components (D) and (E) with the polymer-containing energy ray-curable component (I), tackiness and peelability before curing, strength after curing, adhesion to other layers, Storage stability can be improved. The compounding quantity of these other components is not specifically limited, It determines suitably in the range of 0-40 mass parts with respect to 100 mass parts of energy-beam curable copolymers (A).

  Next, the case where the polymer-containing energy beam curable component (I) is mainly composed of a mixture of a polymer component having no energy beam curable property and an energy beam curable polyfunctional monomer and / or oligomer will be described below. To do.

  As a polymer component which does not have energy-beam sclerosis | hardenability, the component similar to the acrylic copolymer (a1) mentioned above can be used, for example. The content of the polymer component having no energy beam curability in the energy beam curable resin composition is preferably 20 to 99.9% by mass, and more preferably 30 to 80% by mass.

  As the energy ray-curable polyfunctional monomer and / or oligomer, the same one as the above-mentioned component (B) is selected. The blending ratio of the polymer component having no energy beam curability and the energy beam curable polyfunctional monomer and / or oligomer is 10 to 150 parts by mass of the polyfunctional monomer and / or oligomer with respect to 100 parts by mass of the polymer component. It is preferable that it is, and it is especially preferable that it is 25-100 mass parts.

  Also in this case, the photopolymerization initiator (C) and the crosslinking agent (E) can be appropriately blended as described above.

（式中、Ｒ_１は水素またはメチル基であり、ｎは０〜５の整数である。）
で表される化合物（II）において、ｎの好ましい値は０〜３である。化合物（II）の具体例としては、アクリル酸、２−カルボキシエチルアクリレート等が挙げられる。 II. Compound represented by the general formula (1) The following general formula (1)

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 0 to 5.)
In the compound (II) represented by the formula, preferred values of n are 0-3. Specific examples of compound (II) include acrylic acid and 2-carboxyethyl acrylate.

As the compound (II), compounds having different R ₁ values or compounds having different values of n may be used in combination. In this case, it is preferable that the average value of n is 0-3.

  As the compound (II), a commercially available product can be used, or a known synthesis method (for example, “Functional Acrylic Resin” written by Eizo Omori, published by Techno System, 1985, page 19). Those synthesized by a synthesis method) can also be used.

  When the energy ray-curable resin composition according to the present embodiment contains the compound (II), the adhesive property to the reflective film or the information recording layer is improved regardless of the type of the functional group of the acrylic copolymer (a1). While being excellent, an energy ray-curable resin composition (stamper-receiving layer) having a low adhesion to the stamper can be obtained.

  The content of the compound (II) in the energy ray curable resin composition is preferably 0.1 to 50% by mass, and particularly preferably 0.1 to 10% by mass. When the content of the compound (II) is less than 0.1% by mass, it is difficult to obtain an effect of improving the adhesion to the reflective film or the information recording layer by the compound (II). When the content of the compound (II) exceeds 50% by mass, the unreacted compound (II) remains after irradiation with energy rays, and the stamper may be contaminated during the production of the optical recording medium.

  The energy ray-curable resin composition according to the present embodiment includes, for example, an ultraviolet absorber, an antioxidant, a tackifier, in addition to the polymer-containing energy ray-curable component (I) and the compound (II) described above. Various additives such as dyes and coupling agents may be contained. The compounding quantity of these additives is not specifically limited, In the energy ray curable resin composition, it determines suitably in the range of about 0-30 mass%.

  The energy ray-curable resin composition for a stamper-receiving layer according to this embodiment can be obtained by mixing the above-described components by a conventional method.

[Sheet for optical recording medium production]
FIG. 1 is a cross-sectional view of an optical recording medium manufacturing sheet according to an embodiment of the present invention, and FIGS. 2A to 2F are optical disk manufactures using the optical recording medium manufacturing sheet of the embodiment. It is sectional drawing which shows an example of a method.

  The optical recording medium manufacturing sheet 1 according to the present embodiment includes a stamper receiving layer 11 and release sheets 12 and 12 ′ laminated on both surfaces of the stamper receiving layer 11. However, the release sheets 12 and 12 ′ are peeled off when the optical recording medium manufacturing sheet 1 is used.

  The stamper-receiving layer 11 is a layer in which the concavo-convex pattern formed on the stamper is transferred to form pits or grooves / lands, and the information recording layers 3 and 3 ′ are formed or bonded.

  This stamper receiving layer 11 is composed of the energy ray curable resin composition described above. Accordingly, the stamper-receiving layer 11 exhibits excellent adhesion to the information recording layers 3 and 3 ′ and has low adhesion to the stamper.

The storage modulus of the stamper-receiving layer 11 before curing is preferably 1 × 10 ³ to 1 × 10 ⁶ Pa, and particularly preferably 1 × 10 ^{4 to} 5 × 10 ⁵ Pa. Here, the measurement temperature of the “storage modulus before curing” is the same temperature as the working environment in which the stamper and the optical disc manufacturing sheet 1 are overlapped (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.

  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.

Further, the storage elastic modulus after curing of the stamper-receiving layer 11 is preferably 1 × 10 ⁷ Pa or more, and particularly preferably 1 × 10 ⁸ to 1 × 10 ¹¹ Pa. 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.

  When the storage elastic modulus after curing of the stamper receiving layer 11 is in the above range, the pits or grooves / lands transferred to the stamper receiving layer 11 are securely fixed by curing, and the stamper and the stamper receiving layer 11 are bonded. During separation, there is no risk of pits or grooves / lands being destroyed or deformed.

  The thickness of the stamper receiving layer 11 is determined in consideration of the depth of the uneven pattern (pit / groove / land) to be formed, and is preferably 5 to 100 μm, and particularly preferably 5 to 60 μm. Furthermore, it is preferable that it is 15-40 micrometers.

  As the release sheets 12 and 12 ′, conventionally known ones can be used. For example, a release film of a resin film such as polyethylene terephthalate or polypropylene with a silicone release agent or the like can be used.

  The release sheets 12 and 12 ′ have a surface roughness (Ra) of 0.1 μm or less on the side subjected to the release treatment (side in contact with the stamper receiving layer 11) in order to impart smoothness to the stamper receiving layer 11. Is preferred. Further, the thickness of the release sheets 12 and 12 ′ is usually about 10 to 200 μm, preferably about 20 to 100 μm.

  Of the release sheets 12 and 12 ', it is preferable that the first release from the stamper-receiving layer 11 is a light release type, and the later release is a heavy release type.

  The optical recording medium manufacturing sheet 1 according to the present embodiment is prepared by preparing a coating agent containing the energy ray curable resin composition described above and, if desired, a solvent, a kiss roll coater, a reverse roll coater, a knife coater, The stamper receiving layer 11 is formed by coating the release treatment surface of the release sheet 12 with a coating machine such as a roll knife coater or a die coater, followed by drying. Then, another release sheet 12 is formed on the surface of the stamper receiving layer 11. It is obtained by laminating both of the peeled surfaces of '.

  Next, an example of a method for manufacturing an optical disc D (single-sided, double-layered; an example of an optical recording medium) using the optical recording medium manufacturing sheet 1 will be described.

  First, as shown in FIG. 2A, an optical disk substrate 2 having a concavo-convex pattern composed of pits or grooves / lands is manufactured. The optical disk substrate 2 is usually made of polycarbonate and can be formed by a molding method such as injection molding.

  A first information recording layer 3 is formed on the concave / convex pattern of the optical disk substrate 2 as shown in FIG. The first information recording layer 3 is usually composed of a film made of an inorganic material or a laminate of the films. For example, the first information recording layer 3 is a reflective film only, or a reflective film, a dielectric film, a phase change film, and a dielectric film in order from the bottom. It is comprised by the laminated body which consists of a body film. These films can be formed by means such as sputtering.

  As a material of the reflective film, for example, metals such as Al, Ag, Au, Cu, Ta, W and alloys thereof, for example, Al—Cr, Ag—Pt—Cu added with Cr, Pt, Nd, etc. Ag-Nd or the like can be used. The thickness of the reflective film is usually about 3 to 200 nm.

As a material of the dielectric film, for example, a single material made of SiO ₂ , ZnS—SiO ₂ , Si—SiO ₂ , TiO ₂ , ZnO, MgO, or the like, or a combination thereof can be used. The thickness of the dielectric film and the dielectric film is usually about 20 to 200 nm.

  As a material for the phase change film, for example, a chalcogen alloy thin film such as Ge—Te, Ge—Te—Sb, Ge—Sn—Te, or a Sb—Te eutectic thin film can be used. . The thickness of the phase change film is usually about 5 to 20 nm.

  The first information recording layer 3 may be a laminate composed of a reflective film and a dye film from below. Examples of the dye of the dye film include polymethine dyes, anthraquinone dyes, cyanine dyes, and phthalocyanine dyes. The dye film is formed by a spin coating method or the like, and the thickness is usually about 20 to 2000 nm.

  Next, the release sheet 12 ′ of the optical recording medium manufacturing sheet 1 is peeled and removed to expose the stamper receiving layer 11, and the stamper receiving layer 11 is placed on the first optical disk substrate 2 as shown in FIG. The information recording layer 3 is pressed onto the surface. Then, the release sheet 12 laminated on the stamper receiving layer 11 is peeled off and the stamper receiving layer 11 is exposed.

  Next, as shown in FIG. 2D, 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. In this state, the energy beam irradiation device is used to irradiate the stamper receiving layer 11 with energy rays from the stamper S side or the optical disc substrate 2 side, thereby curing the stamper receiving layer 11.

As energy rays, ultraviolet rays, electron beams, etc. are usually used. The amount of energy beam irradiation varies depending on the type of energy beam. For example, in the case of ultraviolet rays, the amount of light is preferably about 100 to 500 mJ / cm ² , and in the case of electron beams, it is preferably about 10 to 1000 krad.

  The stamper S is made of a metal material such as a nickel alloy or a transparent resin material such as norbonene resin. In addition, although the shape of the stamper S illustrated in FIG. 2D is a plate shape, the shape is not limited to this, and may be a roll shape.

  When the stamper receiving layer 11 is cured, the stamper S and the stamper receiving layer 11 are separated. Since the stamper receiving layer 11 has a high adhesive force to the first information recording layer 3 and a low adhesive force to the stamper S, when the stamper S and the stamper receiving layer 11 are separated, the stamper receiving layer 11 and the first information recording layer 3 are separated from each other. The information recording layer 3 is prevented from peeling off.

  When the concavo-convex pattern of the stamper S is transferred and fixed to the stamper receiving layer 11 as described above to form pits or grooves / lands, the concavo-convex pattern of the stamper receiving layer 11 is then formed as shown in FIG. A second information recording layer 3 ′ is formed on the pattern.

  This second information recording layer 3 ′ is usually composed of a film made of an inorganic material or a laminate of the films. For example, only the reflective film (semi-transparent film) or the reflective film (semi-transparent film) in order from the bottom. ), A laminate composed of a dielectric film, a phase change film, and a dielectric film. Further, a dielectric film may be further formed below the reflective film (semi-transparent film). These films can be formed by means such as sputtering.

  Examples of the material of the reflective film (semi-transparent film) include metals such as Al, Ag, Au, Cu, Ta, W and alloys thereof, for example, Al—Cr, Ag added with Cr, Pt, Nd, etc. -Pt-Cu, Ag-Nd, etc. can be used. The thickness of the reflective film (semi-transparent film) is usually about 3 to 20 nm. The material of the film other than the reflective film (semi-transparent film) is the same as the material of the film constituting the first information recording layer 3.

  Finally, as shown in FIG. 2 (f), a protective sheet 5 is laminated on the second information recording layer 3 ′ via an adhesive 4 to obtain an optical disk D. This protective sheet 5 constitutes a part of the optical disk D such as a light receiving surface and a label surface of the optical disk, and for example, a sheet (film) made of a resin such as polycarbonate, polymethyl methacrylate, polystyrene or the like is used. As the adhesive 4, for example, an acrylic ultraviolet curable adhesive can be used.

  In the optical disk D obtained as described above, since the adhesive force between the stamper-receiving layer 11, the first information recording layer 3 and the second information recording layer 3 ′ is high, the manufacturing process or product storage is performed. The resulting delamination is unlikely to occur.

  In the optical recording medium manufacturing method, a single-sided, dual-layer optical disk is manufactured using the optical recording medium manufacturing sheet 1, but the present invention is not limited to this. For example, for manufacturing the optical recording medium A single-sided single-layer optical disc can also be manufactured using the sheet 1.

  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.

  For example, the release sheet 12 or the release sheet 12 ′ in the optical recording medium manufacturing sheet 1 may be omitted.

  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.

[Example 1]
An acrylic copolymer obtained by reacting 52 parts by mass of n-butyl acrylate, 20 parts by mass of methyl methacrylate, and 28 parts by mass of 2-hydroxyethyl acrylate in a mixed solvent of ethyl acetate / methyl ethyl ketone (mass ratio 50:50). A solution (solid content concentration 35% by mass) was obtained.

  To the above acrylic copolymer solution, 33.7 parts by mass of 2-methacryloyloxyethyl isocyanate (90 equivalents with respect to 100 equivalents of hydroxyl group in the acrylate copolymer) and 0.5 parts by mass of dibutyltin dilaurate as a catalyst were added. Then, the reaction is carried out at 40 ° C. for 48 hours in a nitrogen atmosphere, the average side chain introduction rate of the methacryloyl group which is an energy ray curable group is 25.4 mol%, and the weight average molecular weight (Mw) is about 780,000. An energy ray-curable acrylic ester copolymer was obtained. Methyl ethyl ketone was added to the energy ray-curable acrylic ester copolymer to adjust the solid content concentration to 30% by mass.

なお、得られた化合物（II）におけるｎの平均値は１．３であった。 Further, 20 g of acrylic acid, 20 g of furan, and 0.02 g of methoxyhydroquinone were reacted at 160 ° C. for 5 hours in an autoclave. After completion of the reaction, furan and unreacted acrylic acid were removed under reduced pressure. ^When the structure of the product was confirmed from the ¹ HNMR spectrum, it was found to be a compound (II) represented by the following formula (1).

In addition, the average value of n in the obtained compound (II) was 1.3.

  100 parts by mass (30 parts by mass as a solid content) of the energy ray-curable acrylic acid ester copolymer, and dimethylol tricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) as an energy ray-curable bifunctional monomer 25 parts by weight of light acrylate DCP-A), 0.1 part by weight of the above compound (II), and 2,2-dimethoxy-1,2-diphenylethane-1-one (Ciba Specialty) as a photopolymerization initiator Chemicals, Irgacure 651) 1.7 parts by mass and a polyisocyanate compound cross-linking agent (Toyo Ink Mfg. Co., Ltd., Orbine BHS-8515) 1.5 parts by mass (0.56 parts by mass as the solid content) In addition, methyl ethyl ketone is added as a solvent to adjust the solid content concentration to 40% by mass, did.

  Meanwhile, a heavy release release sheet (SP-PET50C, manufactured by Lintec Co., Ltd., surface roughness of the release treated surface) obtained by subjecting one surface of a polyethylene terephthalate (PET) film (thickness: 50 μm) to release treatment with a heavy release silicone resin. = 0.016 μm), and a light release type release sheet (SP-PET38GS, manufactured by Lintec Co., Ltd., release surface treated with a light release type silicone resin on one side of a PET film (thickness: 38 μm): Two types of release sheets (Ra = 0.023 μm) were prepared.

  The above-mentioned coating agent for the stamper-receiving layer is applied to the release-treated surface of the heavy release type release sheet with a knife coater and dried at 90 ° C. for 1 minute to form a stamper-receiving layer having a thickness of 25 μm. The release treatment surface side of the light release type release sheet was bonded to the surface to obtain a sheet for manufacturing an optical recording medium.

[Example 2]
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that the amount of compound (II) was 0.25 parts by mass. Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

Example 3
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that the amount of compound (II) was 1.0 part by mass. Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

Example 4
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that 0.25 part by mass of acrylic acid was used instead of compound (II). Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

Example 5
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that 0.25 part by mass of 2-carboxyethyl acrylate (manufactured by Aldrich) was used instead of compound (II). Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

Example 6
85 parts by mass of n-butyl acrylate and 15 parts by mass of 2-hydroxyethyl acrylate are reacted in a mixed solvent of ethyl acetate / methyl ethyl ketone (mass ratio 50:50) to obtain an acrylic copolymer solution (solid content concentration 35 masses). %).

  100 parts by mass of the obtained acrylic copolymer solution (35 parts by mass as the solid content) and dimethylol tricyclodecane diacrylate (Kyoeisha Chemical Co., Ltd., light acrylate DCP) as an energy ray-curable bifunctional monomer -A) 20 parts by mass, 0.1 part by mass of the compound (II), and 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator , Irgacure 651) 1.7 parts by mass and 1.5 parts by mass (0.56 parts by mass as the solid content) of a crosslinking agent made of a polyisocyanate compound (Olivein BHS-8515, manufactured by Toyo Ink Manufacturing Co., Ltd.) Further, methyl ethyl ketone was added as a solvent to adjust the solid content concentration to 40% by mass to obtain a coating agent for a stamper-receiving layer.

  Using the above-mentioned coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

そして、得られたスタンパー受容層用の塗布剤を使用して、実施例１と同様にして光記録媒体製造用シートを作製した。 [Comparative Example 1]
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that 0.25 parts by mass of a compound having the following structural formula (manufactured by Kyoei Chemical Co., Ltd., HOA-MS) was used instead of compound (II). did.

Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

そして、得られたスタンパー受容層用の塗布剤を使用して、実施例１と同様にして光記録媒体製造用シートを作製した。 [Comparative Example 2]
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1, except that 0.25 parts by mass of a compound having the following structural formula (HOE-HH, manufactured by Kyoei Chemical Co., Ltd.) was used instead of compound (II). did.

Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

そして、得られたスタンパー受容層用の塗布剤を使用して、実施例１と同様にして光記録媒体製造用シートを作製した。 [Comparative Example 3]
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that 0.25 parts by mass of a compound having the following structural formula (HOE-MPL, manufactured by Kyoei Chemical Co., Ltd.) was used instead of compound (II). did.

Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

[Comparative Example 4]
A coating agent for a stamper-receiving layer was prepared in the same manner as in Example 1 except that compound (II) was not used. Then, using the obtained coating agent for the stamper-receiving layer, an optical recording medium production sheet was produced in the same manner as in Example 1.

[Test example]
(1) Measurement of Storage Elastic Modulus after Curing of Stamper Receiving Layer Irradiation with ultraviolet rays was performed on the optical recording medium production sheets produced in Examples and Comparative Examples (Product name: Adwill RAD-2000m / 8) Irradiation conditions: illuminance of 310 mW / cm ² , light quantity of 300 mJ / cm ² ), and the stamper receiving layer was cured. The storage elastic modulus of the stamper-receiving layer after the curing was measured at a value of 50 ° C. at 11 Hz using a dynamic thermomechanical measurement device (TA Instruments, device name: Q800). The results are shown in Table 1.

(2) Measurement of adhesive strength The light release type release sheet was peeled off from the optical recording medium manufacturing sheet produced in the examples and comparative examples, and instead, a 25 μm thick polyethylene terephthalate substrate and a 20 μm thick substrate were used. A sheet composed of an adhesive layer (manufactured by Lintec, PAT1) was bonded so that the adhesive layer and the stamper-receiving layer were in contact with each other.

The obtained laminated sheet was cut to a width of 25 mm, and the stamper-receiving layer exposed by peeling the heavy release type release sheet from the laminated sheet was pressure-bonded to a substrate with a silver reflective film or a nickel plated substrate using a 2 kg rubber roll. . The obtained laminate was irradiated with ultraviolet rays (manufactured by Lintec Corporation, apparatus name: Adwill RAD-2000 m / 8, irradiation conditions: illuminance: 310 mW / cm ² , light amount: 300 mJ / cm ² ), according to JIS Z0237 Then, the adhesive strength between the cured stamper receiving layer and the silver reflective film (vs. Ag reflective film) and the adhesive strength between the cured stamper receiving layer and nickel (vs. Ni) (both 180 ° peel) were measured. The results are shown in Table 1.

(3) Corrosion test The light release type release sheet is peeled off from the optical recording medium manufacturing sheet prepared in the examples and comparative examples, and the exposed stamper receiving layer is reflected on the reflective film surface of the polycarbonate substrate on which the silver reflective film is deposited. Affixed to. Thereafter, ultraviolet rays are irradiated from the side of the heavy release type release sheet (manufactured by Lintec Corporation, apparatus name: Adwill RAD-2000 m / 8, irradiation conditions: illuminance: 310 mW / cm ² , light quantity: 300 mJ / cm ² ), stamper receiving layer Was cured.

  Next, the heavy release type release sheet is peeled off from the stamper-receiving layer, placed in a constant temperature and humidity chamber at 80 ° C. and 90% Rh for 72 hours, and then the reflective film is formed using a confocal microscope (Leathertec, HD100). The condition was observed. The case where corrosion was not confirmed was evaluated as ○.

  As is apparent from Table 1, the stamper-receiving layer of the optical recording medium production sheet prepared in the examples has a storage elastic modulus suitable as a stamper-receiving layer, and has a high adhesive strength and nickel for the silver reflective film. In contrast, it exhibits a low adhesive force and can also suppress corrosion of the reflective film.

  The present invention is useful for stably producing an optical recording medium having no delamination.

It is sectional drawing of the sheet | seat for optical recording medium manufacture which concerns on one Embodiment of this invention. It is sectional drawing which shows an example of the optical disk manufacturing method using the sheet | seat for optical recording medium manufacture concerning the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sheet | seat for optical recording medium manufacture 11 ... Stamper receiving layer 12, 12 '... Release sheet 2 ... Optical disk substrate 3 ... 1st information recording layer 3' ... 2nd information recording layer 4 ... Adhesive 5 ... Protective sheet

Claims (7)

An energy ray curable resin composition for forming a stamper receiving layer laminated on a reflective film formed from silver, a silver alloy or aluminum in an optical recording medium and to which a concavo-convex pattern of a stamper formed from nickel is transferred There,
A polymer-containing energy ray-curable component; and
The following general formula (1)

(In the formula, R ₁ is hydrogen or a methyl group, and n is an integer of 0 to 5.)
Contains a compound represented by,
The energy beam for a stamper-receiving layer, wherein the content of the compound represented by the general formula (1) in the energy beam curable resin composition is 0.1 to 10% by mass. Curable resin composition.   2. The energy ray-curable resin composition for a stamper-receiving layer according to claim 1, wherein the polymer-containing energy ray-curable component is mainly composed of a polymer having energy ray-curability.   The energy ray-curable resin composition for a stamper-receiving layer according to claim 2, wherein the polymer-containing energy ray-curable component further contains an energy ray-curable monomer and / or oligomer.   The polymer-containing energy ray-curable component is mainly composed of a mixture of a polymer having no energy ray-curability and an energy ray-curable polyfunctional monomer and / or oligomer. An energy ray-curable resin composition for a stamper-receiving layer.   Each component contained in the polymer-containing energy ray-curable component does not substantially contain an acidic functional group, and the energy ray-curing property for the stamper-receiving layer according to any one of claims 1 to 4. Resin composition. In an optical recording medium, a sheet for manufacturing an optical recording medium comprising a stamper-receiving layer laminated on a reflective film formed from silver, a silver alloy or aluminum, to which a concave / convex pattern of a stamper formed from nickel is transferred, The said stamper receiving layer consists of an energy-beam curable resin composition in any one of Claims 1-5, The sheet | seat for optical recording medium manufacture characterized by the above-mentioned. An optical recording medium manufactured using the optical recording medium manufacturing sheet according to claim 6 ,
A reflective film formed from silver, a silver alloy or aluminum;
A stamper-receiving layer laminated on the reflective film, to which a concavo-convex pattern of a stamper formed from nickel is transferred;
Optical recording medium comprising the.

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