JP2008192200A - Sheet for manufacturing optical recording medium, optical recording medium, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for manufacturing an optical recording medium which can prevent peeling during a manufacturing process of an optical recording medium or storing a product (optical recording medium). <P>SOLUTION: A sheet 1 for manufacturing an optical disk contains a (meta) acrylic ester copolymer and an energy ray curable resin which has a polycarbonate bone skeleton as indispensable components, and has an energy ray curable layer 11 which contains further a (meta) acrylic ester monomer which has an alicyclic structure as needed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical recording medium manufacturing sheet capable of manufacturing an optical recording medium by forming a stamper-receiving layer or the like in the optical recording medium, an optical recording medium manufactured using such an optical recording medium manufacturing sheet, and the optical recording medium It relates to a manufacturing method.

As a method of manufacturing an optical disk, a dry photocurable film was laminated on an optical disk substrate made of polycarbonate, and then a stamper was pressure-bonded to the dry photocurable film, and light was irradiated in this state to cure the photocurable film. Thereafter, a method of separating a photocured film and a stamper and forming a light reflecting layer on an embossed surface of the photocured film is known (Patent Document 1).
Japanese Patent No. 2959689

  The photo-curable film is cured by irradiation with light, resulting in a decrease in adhesion and separation from the stamper. At the same time, the adhesion to polycarbonate, which is the material of the optical disk substrate, is also reduced. The optical disk substrate made of polycarbonate and the film after photocuring may be separated, or the completed optical disk may be peeled off between layers depending on storage conditions.

  The present invention has been made in view of such a situation, and an optical recording medium manufacturing sheet capable of preventing peeling that may occur during the manufacturing process of an optical recording medium or during storage of a product (optical recording medium). The purpose is to provide.

  In order to achieve the above object, first, the present invention is characterized by including an energy ray curable layer containing a (meth) acrylic acid ester copolymer and an energy ray curable resin having a polycarbonate skeleton. An optical recording medium manufacturing sheet is provided (claim 1).

  In the said invention (invention 1), the energy-beam curable layer contains the energy beam-curable resin having a polycarbonate skeleton, so that the adhesive force to the polycarbonate is high. Therefore, when the cured energy beam curable layer and the stamper are separated, the energy beam curable layer is prevented from peeling off from the polycarbonate layer such as a polycarbonate substrate, a sheet, or a film. It is prevented that the energy ray curable layer and the polycarbonate layer are peeled off during storage.

  The “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 (eg, CD, CD-ROM, CD-R, CD-RW, DVD, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, LD, Blu-ray Disc, HD DVD, MO, etc .; Including)), but is not necessarily limited thereto.

  In the said invention (invention 1), it is preferable that the said (meth) acrylic acid ester copolymer has a carboxyl group (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said energy-beam curable layer contains the (meth) acrylic acid ester monomer which has an alicyclic structure further (invention 3).

  Secondly, according to the present invention, a stamper is pressure-bonded to the energy ray curable layer of the sheet for manufacturing an optical recording medium (claims 1 to 3), and the energy ray curable layer is irradiated with an energy ray to thereby form the energy ray. A method for producing an optical recording medium, comprising: a step of transferring and fixing the uneven pattern of the stamper to the energy ray curable layer by peeling the stamper after curing the curable layer. (Claim 4).

  Thirdly, the present invention provides an optical recording medium manufactured using the sheet for manufacturing an optical recording medium (claims 1 to 3) (claim 5).

  According to the sheet for producing an optical recording medium of the present invention, it is possible to prevent peeling between the cured energy ray curable layer and the polycarbonate layer, which may occur during the production process of the optical recording medium or during product storage.

Hereinafter, embodiments of the present invention will be described. In the present embodiment, an optical disk will be described as an example of an optical recording medium.
[Sheet for optical disc production]
FIG. 1 is a cross-sectional view of an optical disk manufacturing sheet according to an embodiment of the present invention. The optical disk manufacturing sheet 1 according to this embodiment includes an energy beam curable layer 11 and release sheets 12 and 12 ′ laminated on both surfaces of the energy beam curable layer 11. However, the release sheets 12 and 12 ′ are peeled off when the optical disc manufacturing sheet 1 is used.

  The energy ray curable layer 11 in the present embodiment is a layer that can form a stamper receiving layer in which an uneven pattern formed on a stamper is transferred to form a pit or a groove / land in an optical disc.

  The energy beam curable layer 11 contains (meth) acrylic acid ester copolymer (A) and an energy beam curable resin (B) having a polycarbonate skeleton as essential components. The (meth) acrylic acid ester copolymer (A) has desirable properties as a stamper-receiving layer, and can accurately transfer the uneven pattern of the stamper, and can be peeled off from the stamper after curing. There is almost no deposit on the stamper. The energy ray curable resin (B) having a polycarbonate skeleton can improve the adhesive force of the energy ray curable layer 11 to a polycarbonate layer such as a polycarbonate substrate, a sheet, or a film.

  The (meth) acrylic acid ester copolymer (A) 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 is a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group in the molecule. When the obtained (meth) acrylic acid ester copolymer has a functional group, the (meth) acrylic acid ester copolymer can be cross-linked by a cross-linking agent described later. In addition, when the (meth) acrylic acid ester copolymer has a carboxyl group in particular, the energy beam curable layer 11 and a metal thin film formed on the energy beam curable layer 11 (a reflective film for recording and reproduction, etc.) And the strength and durability of the resulting optical disk are improved.

  More specific examples of the functional group-containing monomer as described above include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and other hydroxyl group-containing acrylates, acrylic acid, Examples thereof include carboxyl group-containing compounds such as methacrylic acid and itaconic acid, and these are used alone or in combination of two or more.

  As the (meth) acrylic acid ester monomer, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, or (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group is used. Among these, (meth) acrylic acid alkyl esters having an alkyl group with 1 to 18 carbon atoms, particularly methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, and the like are used.

  The (meth) acrylic acid ester copolymer contains the structural unit derived from the functional group-containing monomer in an amount of usually 3 to 99% by mass, preferably 5 to 40% by mass, particularly preferably 10 to 30% by mass. The structural unit derived from a (meth) acrylic acid ester monomer or a derivative thereof is usually 1 to 97% by mass, preferably 60 to 95% by mass, particularly preferably 70 to 90% by mass.

  A (meth) acrylic acid ester copolymer is 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. Also, 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).

  The mass average molecular weight of the (meth) acrylic acid ester copolymer is preferably 100,000 or more, particularly preferably 150,000 to 1,500,000, and more preferably 200,000 to 1,000,000. 000 is preferred.

  Moreover, as a (meth) acrylic acid ester copolymer, you may have an energy-beam curable group in a side chain. The (meth) acrylic acid ester copolymer having an energy ray-curable group in the side chain is a non-functional group having a substituent that binds the functional group-containing monomer unit (meth) acrylic copolymer to the functional group. It is obtained by reacting with a saturated group-containing compound.

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

  Specific examples of the unsaturated group-containing compound include, for example, methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate; diisocyanate compound or polyisocyanate compound And acryloyl monoisocyanate compound obtained by reaction of hydroxyethyl (meth) acrylate; acryloyl monoisocyanate obtained by reaction of diisocyanate compound or polyisocyanate compound, polyol compound and hydroxyethyl (meth) acrylate Nate compound; glycidyl (meth) acrylate; (meth) acrylic acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-isopropyl And lopenyl-2-oxazoline.

  The mass average molecular weight of the (meth) acrylic acid ester copolymer having an energy ray-curable group in the side chain is preferably 100,000 or more, and particularly preferably 150,000 to 1,500,000. Furthermore, it is preferable that it is 200,000-1,000,000.

  Examples of the energy ray curable resin (B) having a polycarbonate skeleton include (meth) acrylates having a polycarbonate skeleton such as polycarbonate urethane (meth) acrylate, polycarbonate polyester (meth) acrylate, and polycarbonate polyamide (meth) acrylate. Compounds. These may be used alone or in combination of two or more. Among the above, it is preferable to use polycarbonate urethane (meth) acrylate. In addition, the number of (meth) acryloyl groups contained in one molecule of (meth) acrylate having a polycarbonate skeleton is preferably 2 to 6. When the number of (meth) acryloyl groups is 2 to 6, when used as a stamper-receiving layer, the shape of the transferred unevenness after curing is good and the polycarbonate layer is deformed (warped). Hard to do.

  Polycarbonate urethane (meth) acrylate is produced, for example, by reacting polycarbonate urethane (meth) acrylate obtained by reacting polycarbonate diol, diisocyanate compound, and hydroxyl group-containing (meth) acrylic acid ester. can do.

  The mass average molecular weight of the energy ray curable resin (B) having a polycarbonate skeleton is preferably 200 to 30000, and particularly preferably 3000 to 20000.

  The compounding quantity with respect to the (meth) acrylic acid ester copolymer (A) of energy beam curable resin (B) which has a polycarbonate frame | skeleton is 1 with respect to 100 mass parts of (meth) acrylic acid ester copolymers (A). It is preferable that it is -100 mass parts, and it is especially preferable that it is 3-60 mass parts. When the blending amount of the energy beam curable resin (B) having a polycarbonate skeleton is less than 1 part by mass, the effect of improving the adhesive strength of the energy beam curable layer 11 to the polycarbonate layer cannot be sufficiently obtained. On the other hand, when the blending amount of the energy beam curable resin (B) having a polycarbonate skeleton exceeds 100 parts by mass, the energy beam curable layer 11 may be deformed because the cohesive force of the energy beam curable layer is reduced. .

  In the energy ray curable layer 11, in addition to the above components, other components may be appropriately blended. Other components include, for example, crosslinker (C), energy beam polymerization initiator (D), energy other than (meth) acrylate monomer (E), (B) and (E) having an alicyclic structure. Examples thereof include a linear curable resin (F) and other additives (G).

  As a crosslinking agent (C), the polyfunctional compound which has the reactivity with the functional group which (meth) acrylic acid ester 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 using the crosslinking agent (C), the strength and the like of the energy beam curable layer 11 before and after curing can be improved. The crosslinking agent (C) is used in an amount in the range of 0.001 to 30 parts by mass, particularly 0.01 to 15 parts by mass with respect to 100 parts by mass of the (meth) acrylic acid ester copolymer (A). Is preferred.

  As the energy ray polymerization initiator (D), a photopolymerization initiator is used when ultraviolet rays are used as the energy rays. By using a photopolymerization initiator, the polymerization curing time and the amount of light irradiation can be reduced.

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

  The energy ray polymerization initiator (D) is based on 100 parts by mass of the total amount of the energy ray curable resin (B) having a polycarbonate skeleton and the (meth) acrylic acid ester monomer (E) having an alicyclic structure. It is preferably used in an amount in the range of 0.1 to 50 parts by mass, particularly 0.5 to 30 parts by mass.

  Since the (meth) acrylic acid ester monomer (E) having an alicyclic structure has an action of reducing the adhesion to metal, when the stamper is made of a metal such as nickel, the energy ray curable layer 11 from the stamper Peelability can be improved.

  Examples of the (meth) acrylic acid ester monomer (E) having an alicyclic structure include tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclodecane di (meth) acrylate, and dicyclopentanyl (meth) acrylate. , Dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, and the like.

  The (meth) acrylic acid ester monomer (E) having an alicyclic structure is preferably blended in an amount of 1 to 45 mass%, particularly preferably 5 to 30 mass%, in the energy ray curable layer 11. .

  Examples of the energy ray curable resin (F) other than (B) and (E) include urethane (meth) acrylate, epoxy (meth) acrylate, and silicone (meth) acrylate. The energy beam curable resin (F) is preferably blended in the energy beam curable layer 11 in an amount of 45% by mass or less, particularly preferably 1 to 30% by mass.

  Examples of other additives (G) include ultraviolet absorbers, plasticizers, fillers, antioxidants, tackifiers, pigments, dyes, and coupling agents.

The storage elastic modulus of the energy beam curable layer 11 before curing is preferably 1 × 10 ³ to 1 × 10 ⁷ Pa, and particularly preferably 1 × 10 ^{4 to} 5 × 10 ⁶ 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.

  If the storage modulus before curing of the energy ray curable layer 11 is in the above range, the uneven pattern formed on the stamper is energy ray curable simply by pressing the stamper to the energy ray curable layer 11. Precision transfer to the layer 11 makes the manufacture of the optical disc very simple.

Moreover, it is preferable that the storage elastic modulus after hardening of the energy ray curable layer 11 is 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 energy beam curable layer 11 is in the above range, the pits or grooves / lands transferred to the energy beam curable layer 11 are securely fixed by curing, and the stamper and the energy beam are fixed. When separating from the curable layer 11, there is no possibility of pits or grooves / lands being destroyed or deformed.

  The thickness of the energy ray curable layer 11 is determined according to the depth of pits or grooves to be formed, but is usually about 5 to 30 μm, and preferably about 10 to 20 μm.

  The adhesive strength of the optical disk producing sheet 1 having the energy ray curable layer 11 to the polycarbonate after curing is preferably 100 mN / 25 mm or more, and particularly preferably 300 mN / 25 mm or more. When the energy beam curable layer 11 has such an adhesive force, it is possible to prevent the optical disk manufacturing sheet from being peeled off from the polycarbonate material during the manufacturing process of the optical disk. Further, even when long-term storage of the optical disk is assumed, it is possible to prevent interfacial peeling at the energy beam curable layer 11 due to insufficient adhesive force of the cured energy beam curable layer 11. The energy beam curable layer 11 in the present embodiment may have the above-described adhesive force with respect to the polycarbonate by containing the energy beam curable resin (B) having a polycarbonate skeleton.

  In the optical disk manufacturing sheet 1 according to the present embodiment, the energy beam curable layer 11 is easily deformed by pressure. In order to prevent this, release sheets 12 and 12 ′ are laminated on both surfaces of the energy beam curable layer 11. Has been. 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 sheet 12 has a surface roughness (Ra) of 0.1 μm or less on the side subjected to the release treatment (side in contact with the energy ray curable layer 11) in order to impart smoothness to the energy ray curable 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.

  In the case where the release sheet 12 is peeled first and the release sheet 12 ′ is peeled later, the release sheet 12 is preferably a light release type and the release sheet 12 ′ is preferably a heavy release type. .

[Manufacture of optical disc manufacturing sheet]
In order to manufacture the optical disk manufacturing sheet 1 according to the present embodiment, first, a coating material for the energy beam curable layer 11 is prepared, which contains a material constituting the energy beam curable layer 11 and, if desired, a solvent. To do.

  And after apply | coating the coating agent for energy-beam curable layers 11 on the peeling process surface of one peeling sheet 12 (12 ') and making it dry and forming energy-beam curable layer 11, energy-beam curable layer 11 The release treatment surface of the other release sheet 12 ′ (12) is bonded to the surface. For the coating of the coating agent, for example, a coating machine such as a kiss roll coater, a reverse roll coater, a knife coater, a roll knife coater, or a die coater can be used.

[Manufacture of optical discs (1)]
An example of an optical disk manufacturing method using the optical disk manufacturing sheet 1 will be described. FIGS. 2A to 2H are cross-sectional views showing an example of an optical disk manufacturing method using the optical disk manufacturing sheet 1.

  First, as shown in FIGS. 2 (a) to 2 (b), one release sheet 12 (light release type) of the optical disk manufacturing sheet 1 is peeled and removed, and the exposed energy ray curable layer 11 is used as a stamper S. The uneven pattern of the stamper S is transferred to the energy beam curable layer 11 by pressure bonding.

  The stamper S is made of a metal material such as a nickel alloy or a transparent resin material such as a norbornene resin. In addition, although the shape of the stamper S shown in FIGS. 2A to 2E is a plate shape, the shape is not limited to this, and may be a roll shape.

  Next, as shown in FIG. 2 (c), the other release sheet 12 ′ (heavy release type) is peeled off from the energy ray curable layer 11, and the exposed energy ray curable layer 11 is a cover sheet made of polycarbonate. 6 is laminated and pressure-bonded. The cover sheet 6 constitutes the light receiving surface of the optical disc.

  Then, as shown in FIG. 2 (d), with the stamper S in close contact with the energy ray curable layer 11, an energy ray irradiation device (in FIG. 2 (d), for example, a UV lamp L) is used. The energy ray curable layer 11 is irradiated with energy rays from the cover sheet 6 side. Thereby, the energy ray curable material constituting the energy ray curable layer 11 is cured, and the storage elastic modulus is increased.

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.

  Thereafter, as shown in FIG. 2 (e), the stamper S is separated from the energy ray curable layer 11. At this time, since the adhesive force of the energy ray curable layer 11 to the polycarbonate (cover sheet 6) is high, the energy ray curable layer 11 is pulled by the stamper S when the stamper S is separated from the energy ray curable layer 11. Thus, peeling from the cover sheet 6 is prevented.

  After the concave / convex pattern of the stamper S is transferred and fixed to the energy ray curable layer 11 as described above and pits or grooves / lands are formed, next, as shown in FIG. Thus, a transflective film 4 ′ made of a metal thin film such as silver, a silver alloy, or aluminum is formed on the surface of the energy ray curable layer 11.

  Here, when a carboxyl group exists in the material ((meth) acrylic acid ester copolymer (A)) constituting the energy ray curable layer 11, the adhesion between the energy ray curable layer 11 and the transflective film 4 ′ is adhered. The strength is increased, and the strength, durability, and the like of the obtained optical disk are improved.

  Apart from the laminate comprising the cover sheet 6, the energy ray curable layer 11 and the transflective film 4 ′, an optical disk substrate 3 made of polycarbonate and having a predetermined uneven pattern is formed as shown in FIG. 2 (g). Molding is performed by a molding method such as injection molding, and a reflective film 4 made of a metal thin film is formed on the concavo-convex pattern by means such as sputtering.

  Finally, as shown in FIG. 2 (h), the laminate (cover sheet 6 + energy ray curable layer 11 + semi-transmissive reflective film 4 ′) on which the semi-transmissive reflective film 4 ′ is formed, and the reflective film 4 The formed optical disk substrate 3 is bonded via an adhesive 5 so that the transflective film 4 ′ and the reflective film 4 face each other.

  In the optical disk obtained as described above, since the cured energy beam curable layer 11 and the cover sheet 6 are bonded with high adhesive force, the energy beam curable layer 11 and the cover sheet 6 are stored during storage. Delamination is prevented.

[Manufacture of optical discs (2)]
Another example of an optical disk manufacturing method using the optical disk manufacturing sheet 1 will be described. 3A to 3G are cross-sectional views showing an example of an optical disc manufacturing method using the optical disc manufacturing sheet 1.

  First, as shown in FIG. 3A, an optical disk substrate 3 made of polycarbonate and having a predetermined concavo-convex pattern is formed by a molding method such as injection molding, and a metal thin film is formed on the concavo-convex pattern by means such as sputtering. A reflective film 4 made of is formed. Here, since the reflective film 4 is not formed on the peripheral portion of the optical disc substrate 3, the polycarbonate that is the material of the optical disc substrate 3 is exposed at the peripheral portion of the optical disc substrate 3.

  As shown in FIG. 3B, one release sheet 12 (light release type) of the optical disk manufacturing sheet 1 is peeled and removed, and the exposed energy beam curable layer 11 is formed on the optical disk on which the reflective film 4 is formed. Lamination and pressure bonding are performed on the substrate 3. Then, as shown in FIG. 3C, the other release sheet 12 ′ (heavy release type) laminated on the energy ray curable layer 11 is peeled and removed to expose the energy ray curable layer 11.

  Next, as shown in FIG. 3D, a transparent stamper S is pressure-bonded to the exposed surface of the energy ray curable layer 11, and the uneven pattern of the stamper S is transferred to the energy ray curable layer 11. In this state, the energy ray curable layer 11 is irradiated with energy rays from the stamper S side using an energy ray irradiating apparatus (UV lamp L as an example in FIG. 3D). Layer 11 is cured.

  Thereafter, as shown in FIG. 3 (e), the stamper S is separated from the energy ray curable layer 11. At this time, the energy beam curable layer 11 has a high adhesive force to the polycarbonate, and the energy beam curable layer 11 is bonded to the polycarbonate portion at the peripheral edge of the optical disk substrate 3 with a high adhesive force. When separating from the layer 11, the energy beam curable layer 11 is prevented from being pulled from the optical disk substrate 3 by being pulled by the stamper S.

  When the concave / convex pattern of the stamper S is transferred and fixed to the energy ray curable layer 11 as described above to form pits or grooves / lands, then, as shown in FIG. Thus, a transflective film 4 ′ made of a metal thin film is formed on the surface of the energy ray curable layer 11.

  Finally, as shown in FIG. 3 (g), a cover sheet 6 is laminated on the transflective film 4 'with an adhesive 5 to obtain an optical disc.

  In the optical disk obtained as described above, the cured energy beam curable layer 11 and the peripheral portion of the optical disk substrate 3 are bonded with a high adhesive force, so that the energy beam curable layer 11 and the optical disk substrate are stored during storage. 3 is prevented from delamination.

  The optical disc manufacturing methods (1) and (2) are merely examples, and the optical disc manufacturing method using the optical disc manufacturing sheet according to the present embodiment is not limited to these manufacturing methods.

  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 disc 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]
In a nitrogen atmosphere, 80 parts by mass of n-butyl acrylate, 20 parts by mass of acrylic acid, and 0.2 parts by mass of azobisisobutyronitrile (polymerization initiator) were reacted in ethyl acetate at 60 ° C. for 24 hours. Thus, an acrylic ester copolymer solution having a mass average molecular weight of 850,000 (solid content concentration: 35% by mass) was obtained.

  1. 100 parts by mass of the resulting acrylic ester copolymer solution, 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator (manufactured by Ciba Specialty Chemicals, Irgacure 184, solid content concentration: 100% by mass) 0 parts by mass, polycarbonate-based urethane acrylate (manufactured by Negami Kogyo Co., Ltd., UN9000H, mass average molecular weight 5000, number of acryloyl groups in one molecule, solid content concentration 100%) 7.0 parts by mass, and alicyclic structure 10 parts by mass of tricyclodecane dimethanol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate DCP-A, solid content concentration 100% by mass) and a cross-linking agent comprising a polyisocyanate compound (manufactured by Toyo Ink Manufacturing Co., Ltd., (Olivein BHS-8515, solid content concentration 35% by mass) 1.0 part by mass Dissolved, to adjust the solid content concentration to 35 mass%, and an energy ray-curable layer of the coating agent.

  A heavy release type release sheet (SP-PET3811, manufactured by Lintec Co., Ltd., surface roughness (Ra): 0.016 μm) obtained by release treatment with a heavy release type silicone resin on one side of a polyethylene terephthalate (PET) film (thickness: 38 μm) , And 2 of a PET film (thickness: 38 μm), a light release type release sheet (Lintec Corporation, SP-PET3801, surface roughness (Ra): 0.023 μm), which was release-treated with a light release type silicone resin. Various types of release sheets were prepared.

  The energy ray curable layer coating agent obtained above is applied to the release treatment surface of the heavy release type release sheet with a knife coater and dried at 90 ° C. for 1 minute to form an energy ray curable layer having a thickness of 10 μm. Then, the release surface of the light release type release sheet was bonded to the surface of the energy ray curable layer, and this was used as a sheet for optical disc production.

[Example 2]
As the polycarbonate urethane acrylate, UN9200A (mass average molecular weight 15000, number of acryloyl groups in one molecule, solid content concentration 100%) manufactured by Negami Kogyo was used in place of UN9000H manufactured by Negami Kogyo. In the same manner as in Example 1, a sheet for producing an optical disc was produced.

Example 3
Except for using UN9000H manufactured by Negami Kogyo Co., Ltd. as a polycarbonate urethane acrylate, except that UN9000PEP manufactured by Negami Kogyo Co., Ltd. (mass average molecular weight 5000, two acryloyl groups in one molecule, solid concentration 100% by mass) was used. In the same manner as in Example 1, a sheet for producing an optical disk was produced.

Example 4
As a polycarbonate urethane acrylate, instead of UN9000H manufactured by Negami Kogyo Co., Ltd., purple light UV-3210EA manufactured by Nippon Synthetic Chemical Co., Ltd. (mass average molecular weight 5000, number of acryloyl groups in one molecule, solid content concentration 70% by mass) 10 An optical disk producing sheet was produced in the same manner as in Example 1 except that the parts by mass were used.

Example 5
As a polycarbonate urethane acrylate, instead of UN9000H manufactured by Negami Kogyo Co., Ltd., Purple Light UV-3210EA manufactured by Nippon Synthetic Chemical Co., Ltd. (mass average molecular weight 5000, number of acryloyl groups in one molecule, solid content concentration 70% by mass) 5 An optical disk manufacturing sheet was prepared in the same manner as in Example 1 except that 5 parts by mass of urethane acrylate (manufactured by Nippon Synthetic Chemical Co., Ltd., purple light UV-6020, solid content concentration 70% by mass) was blended. did.

Example 6
As a polycarbonate-based urethane acrylate, instead of UN9000H manufactured by Negami Kogyo Co., Ltd., Nippon Kogyo Kagaku's purple light UV-3210EA (mass average molecular weight 5000, number of acryloyl groups in one molecule, solid concentration 70% by mass) 2 A sheet for optical disc production was produced in the same manner as in Example 1 except that 8 parts by mass of urethane acrylate (manufactured by Nippon Synthetic Chemical Co., Ltd., purple light UV-6020, solid content concentration 70% by mass) was blended. did.

[Comparative Example 1]
100 parts by mass of isophorone diisocyanate, 23 parts by mass of neopentyl glycol, and 0.025 parts by mass of dibutyltin dilaurate were reacted at 60 ° C. for 2 hours to obtain a urethane prepolymer. The temperature of the obtained urethane prepolymer was lowered to 40 ° C., 0.15 part by mass of dibutyltin dilaurate and 0.1 part by mass of hydroquinone monomethyl ether as a polymerization inhibitor were added, and 60 parts by mass of 2-hydroxyethyl acrylate was slowly added. The reaction was conducted dropwise. And it was made to react at 60 degreeC continuously for 6 hours, and urethane acrylate (mass average molecular weight 900) was obtained.

  A sheet for producing an optical disk was produced in the same manner as in Example 1 except that the above urethane acrylate was used instead of polycarbonate urethane acrylate (manufactured by Negami Kogyo Co., Ltd., UN9000H).

[Comparative Example 2]
100 parts by mass of isophorone diisocyanate, 54 parts by mass of hydrogenated bisphenol A, and 0.025 parts by mass of dibutyltin dilaurate were reacted at 60 ° C. for 2 hours to obtain a urethane prepolymer. The temperature of the obtained urethane prepolymer was lowered to 40 ° C., 0.15 parts by mass of dibutyltin dilaurate and 0.1 parts by mass of hydroquinone monomethyl ether as a polymerization inhibitor were added, and 60 parts by mass of 2-hydroxyethyl acrylate was added. The reaction was slowly added dropwise. And it was made to react at 60 degreeC continuously for 6 hours, and urethane acrylate (mass mean molecular weight 1000) was obtained.

  A sheet for producing an optical disk was produced in the same manner as in Example 1 except that the above urethane acrylate was used instead of polycarbonate urethane acrylate (manufactured by Negami Kogyo Co., Ltd., UN9000H).

[Test example]
(1) Measurement of adhesive strength The light release type release sheet is peeled off from the optical disc production sheet produced in the example or the comparative example, and the exposed energy ray curable layer is a polycarbonate film (manufactured by Teijin Chemicals, Pure Ace C110, thickness). : 80 μm), and a rubber roll having a width of 45 mm and a weight of 2 kg was reciprocated once to press-bond both.

  The heavy release type release sheet is peeled off from the obtained laminate, and a 20 μm-thick adhesive (PL Thin, manufactured by Lintec Corporation) is laminated on a 50 μm-thick polyethylene terephthalate base material on the exposed energy ray-curable layer. A 25 mm wide adhesive tape was affixed and used as a sample for measuring adhesive strength (before curing).

In addition, the obtained laminate is irradiated with ultraviolet rays (Adtech RAD-2000m / 8, manufactured by Lintec Corporation. Irradiation conditions: illuminance: 310 mW / cm ² , light amount: 300 mJ / cm ² ), and energy ray curable. The layer was cured. Thereafter, the heavy release type release sheet was peeled off, and the cured energy ray curable layer was laminated with a 50 μm thick polyethylene terephthalate base material and a 20 μm thick adhesive (Lintec Co., Ltd., PL thin) 25 mm wide. The adhesive tape was affixed, and this was used as an adhesive strength measurement sample (after curing).

  About the sample for adhesive strength measurement obtained before (after curing and after curing), the adhesive strength to the polycarbonate film of the energy ray curable layer (peeling speed 300 mm / min, peeling angle 180 °) was measured according to JIS Z0237. . The results are shown in Table 1. In all the samples, peeling occurred at the interface between the energy ray curable layer and the polycarbonate.

(2) Evaluation of Peeling from Substrate The light release type release sheet is peeled off from the optical disc manufacturing sheet produced in the example or the comparative example, and the exposed energy ray curable layer is attached to the substrate with the reflective layer, and the width is 45 mm. A rubber roll having a weight of 2 kg was reciprocated once to press-bond both. As a substrate with a reflective layer, a polycarbonate substrate (thickness 1.1 mm) on which pits are formed is produced by an injection molding method, and a reflective layer (thickness 30 nm) made of a silver alloy is sputtered onto the obtained polycarbonate substrate. The one formed by was used.

The resulting laminate is irradiated with ultraviolet rays (Adtech RAD-2000m / 8, manufactured by Lintec Corporation. Irradiation conditions: illuminance: 310 mW / cm ² , light amount: 300 mJ / cm ² ) to form an energy ray curable layer. Cured. Next, the heavy release type release sheet was peeled off, allowed to stand for 240 hours under high-temperature and high-humidity conditions (80 ° C., 85% Rh), and then allowed to stand at room temperature (23 ° C., 50% Rh) for 1 hour. The presence or absence of peeling of the cured energy beam curable layer in this laminate from the substrate was visually observed. The results are shown in Table 1.

  As is apparent from Table 1, the optical disk manufacturing sheet of the example has a very large adhesive force to the polycarbonate as compared with the optical disk manufacturing sheet of the comparative example.

  The present invention is useful for efficiently producing a highly durable optical recording medium in which delamination is prevented.

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sheet for optical disk manufacture 11 ... Energy-beam curable layer 12, 12 '... Release sheet 3 ... Optical disk substrate 4 ... Reflective film 4' ... Semi-transmissive reflective film 5 ... Adhesive 6 ... Cover sheet

Claims (5)

  An optical recording medium manufacturing sheet comprising an energy ray curable layer containing a (meth) acrylic acid ester copolymer and an energy ray curable resin having a polycarbonate skeleton.   The sheet for producing an optical recording medium according to claim 1, wherein the (meth) acrylic acid ester copolymer has a carboxyl group.   The sheet for manufacturing an optical recording medium according to claim 1, wherein the energy ray curable layer further contains a (meth) acrylic acid ester monomer having an alicyclic structure.   A stamper is pressure-bonded to the energy ray curable layer of the optical recording medium production sheet according to any one of claims 1 to 3, and the energy ray curable layer is irradiated with an energy ray to form the energy ray curable layer. A method for producing an optical recording medium, comprising: a step of transferring and fixing the uneven pattern of the stamper to the energy ray curable layer by peeling the stamper after curing.   An optical recording medium manufactured using the optical recording medium manufacturing sheet according to claim 1.

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