JP2008027506A - Manufacturing method of multilayered optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a multilayered optical recording medium which manufactures an optical recording medium with excellent productivity and produces a reliable optical recording medium. <P>SOLUTION: In the manufacturing method of the multilayered optical recording medium having two or more information recording layers provided with patterns composed of pits or guiding grooves constituting two or more information recording tracks, two or more resin layers laminated together with the information recording layers are composed of resins whose glass transition points are in a specific relation between the resin layers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a multilayer optical recording medium, and more particularly to a method for manufacturing a multilayer optical recording medium in which a photoreactive curable resin is applied to a substrate and a recording layer is laminated.

  In recent years, optical recording media are being applied as recording media for recording various kinds of information in fields such as computers and audio visuals. Furthermore, with the spread of mobile computers and the diversification of information, small and large capacity optical recording media are required.

  An optical recording medium that records or reproduces information by light has a fine uneven pattern such as pits and guide grooves for obtaining a tracking servo signal on a substrate, and a recording layer or a reflective layer is formed thereon. In addition, it has a single plate structure in which an organic protective layer is further formed. There is also an optical recording medium having a configuration in which two substrates are bonded with their recording layer or reflecting layer surfaces facing each other.

  In response to the demand for higher density, an optical recording medium in which a plurality of recording layers are formed on one substrate surface has been proposed. Specifically, a plurality of recording layers are formed in contrast to the optical recording medium having the single-plate configuration and the bonded configuration having only one recording layer on one substrate surface. That is, a recording layer is formed on a support substrate on which a signal pattern is formed, and further, a recording layer is formed on the recording layer via a fine concavo-convex pattern forming layer. Optical recording with multiple recording layers on one substrate surface by forming signal pattern formation layer and recording layer formation repeatedly as needed, and finally forming an organic protective layer (cover sheet) on the recording layer A medium is manufactured. The light incident surface for recording / reproducing and erasing information can be from either the substrate surface side or the organic protective layer surface side on the recording layer, and one surface or both surfaces can be used. it can. Incident light is easier to reduce the thickness of the light-transmitting substrate if it is performed from the surface of the organic protective layer. Therefore, the NA (numerical aperture) of the objective lens of the pickup can be increased and the density can be increased. It is known to be advantageous.

  Methods for forming a plurality of recording layers on one substrate surface are disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-260307 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2003-203402 (Patent Document 2). It is also proposed in “Matsushita Technical Journal, Vol. 50, No. 5, Oct. 2004, p. 64-68” (Non-Patent Document 1).

  However, the above prior art has been found to have the following problems.

  In Patent Document 1, Patent Document 2, and Non-Patent Document 1, the following method is proposed as a method for manufacturing an optical recording medium having a multilayer structure.

After forming pits and guide grooves on the substrate surface, forming a reflective layer and a recording layer, and forming the first information recording layer, the following steps are performed.
(1) An ultraviolet curable resin or a dry photopolymer is formed on the first information recording layer.
(2) A resin stamper is superimposed on the ultraviolet curable resin or dry photopolymer to form pits and guide grooves, and the stamper is peeled off.
(3) A translucent film is formed on the pits and guide grooves.
Then, the steps (1) to (3) are repeated (see FIG. 9 (a) or (b) of Patent Document 2).

  The above technique is an application of the conventional Photopolymer (2P) method. The uniformity of the distance between layers and the positional accuracy of each layer can be controlled relatively easily, and it is considered that this is a method for obtaining a high-quality optical recording medium. However, since the translucent film attenuates ultraviolet rays for curing the ultraviolet curable resin and the dry photopolymer, it is necessary to irradiate the ultraviolet rays from the stamper side using a transparent stamper. A resin stamper can be used as the transparent stamper. However, since it is difficult to reuse the resin stamper in terms of productivity and quality, the resin stamper is disposable for each layer formation, which increases the cost.

  A conventional manufacturing method of an optical recording medium having a multilayer structure will be described with reference to FIG.

  6A to 6D show a method for manufacturing an optical recording medium having four information recording surfaces L0 to L3. These drawings show one half of a rotationally symmetric disk-shaped cross-sectional view having a central hole, and the central holes of the substrate and stamper are omitted.

  In FIG. 6A (1), a PC board 15 is a polycarbonate board that is injection-molded using an injection molding stamper A21, and an L0 layer information pattern 16 (pits and guide grooves) is formed on the board. Has been. Typically, the PC board 15 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm.

  In FIG. 6A (2), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer. The L0 layer recording film 17 typically includes a reflective film or a reflective film that does not transmit light.

  In FIG. 6A (3), the 2p resin 18 for the intermediate layer 3 for forming the intermediate layer 3 between the L0 layer and the L1 layer provided on the L0 layer is applied on the L0 layer recording film 17. The resin thickness is, for example, 10 μm. For simplicity, the 2p resin 18 for the intermediate layer 3 is a single layer, but in order to satisfy transferability, peelability, and thickness accuracy, a plurality of resins may be used in combination.

  In FIG. 6A (4), a resin-made transparent stamper A19-1 in which the information pattern of the L1 layer is formed in advance on the 2p resin 18 for the intermediate layer 3 is aligned using a center hole (not shown). , Superimposed. Thereafter, ultraviolet light is irradiated from the UV light source 5 through the transparent stamper A, and the 2p resin 18 for the intermediate layer 3 is cured. The 2p resin 18 for the intermediate layer 3 may be superimposed on the L0 layer recording film 17 on the PC substrate 15 after being applied to the transparent stamper A19-1.

  6A (5), after the 2p resin 18 for the intermediate layer 3 is cured, the transparent stamper A19-1 is peeled off, and the information pattern 13 (pits and guide grooves) of the L1 layer is formed on the substrate. The peeled transparent stamper A deteriorates because it is irradiated with ultraviolet rays, and not only cannot be reused as a stamper, but also its use is limited for reuse.

  In FIG. 6A (6), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer. The L1 layer recording film 14 is a translucent film.

  In FIG. 6A (7), the 2p resin 11 for the intermediate layer 2 for constituting the intermediate layer 2 between the L1 layer and the L2 layer provided on the L1 layer is similarly applied on the L1 layer recording film 14. The The resin thickness is, for example, 15 μm.

  In FIG. 6A (8), a resin-made transparent stamper B19-2 in which the information pattern of the L2 layer is formed in advance on the 2p resin 11 for the intermediate layer 2 is aligned using a center hole (not shown). , Superimposed. Thereafter, similarly, ultraviolet rays are irradiated from the UV light source 5 through the transparent stamper B, and the 2p resin 11 for the intermediate layer 2 is cured.

  6A (9), after the 2p resin 11 for the intermediate layer 2 is cured, the transparent stamper B19-2 is peeled off, and the information pattern 9 (pits and guide grooves) of the L2 layer is formed on the substrate. After all, the peeled transparent stamper B deteriorates because it is irradiated with ultraviolet rays, and cannot be reused as a stamper.

  6A (10), the L2 layer recording film 10 is formed on the information pattern 9 of the L2 layer. Similarly, the L2 layer recording film 10 is a translucent film.

  In FIG. 6A (11), the 2p resin 7 for the intermediate layer 1 for constituting the intermediate layer 1 between the L2 layer and the L3 layer provided on the L2 layer is similarly applied on the L2 layer recording film 10. The The resin thickness is, for example, 10 μm.

  In FIG. 6A (12), a resin-made transparent stamper C19-3 in which the information pattern of the L3 layer is previously formed is aligned on the 2p resin 7 for the intermediate layer 1 using a center hole (not shown). , Superimposed. Thereafter, similarly, ultraviolet rays are irradiated from the UV light source 5 through the transparent stamper C, and the 2p resin 7 for the intermediate layer 1 is cured.

  6A (13), after the 2p resin 7 for the intermediate layer 1 is cured, the transparent stamper C19-3 is peeled off, and the information pattern 4 (pits and guide grooves) of the L3 layer is formed on the substrate. After all, the peeled transparent stamper C deteriorates because it is irradiated with ultraviolet rays, and cannot be reused as a stamper.

  In FIG. 6A (14), the L3 layer recording film 6 is formed on the information pattern 4 of the L3 layer. Similarly, the L3 layer recording film 6 is composed of a translucent film.

  In FIG. 6A (15), the cover sheet 2p resin 2 for forming a cover sheet formed on the L3 layer is similarly applied on the L3 layer recording film 6. The resin thickness is, for example, 70 μm.

In FIG. 6A (16), the ultraviolet light is irradiated from the UV light source 5, and the 2p resin 2 for cover sheets is hardened. Instead of the cover sheet 2p resin, a 70 μm thick resin sheet may be attached.
JP 2002-260307 A JP 2003-203402 A Matsushita Technical Journal, Vol. 50, no. 5, Oct. 2004, p. 64-68

  Thus, in the prior art, in the steps shown in FIGS. 6A (4) to (5), FIGS. 6A (8) to (9) and FIGS. 6C (12) to (13), resin-made transparent stampers A and B are used. And C are used respectively. However, since these are difficult to reuse in terms of productivity and quality, they are thrown away after each layer is formed, and there is a problem that costs are significantly increased. In particular, as the number of layers of the multilayer structure increases, the problem of cost increase due to disposable resin stampers becomes more serious.

  Further, in the method for producing an optical recording medium having the multilayer structure, the photoreactive curable resin is required to have high transferability of the information pattern formed on the stamper. In addition, the stamper is required to be easily peeled off after curing. However, it is difficult to improve the peelability of the stamper while maintaining the transferability of the information pattern and the adhesiveness of the recording film, and there is a problem of a decrease in yield due to poor formation of each resin layer.

  Furthermore, in a multilayer structure in which a plurality of layers of photoreactive curable resin are formed, the occurrence of TILT due to temperature, humidity fluctuation, drop impact, etc. due to stress or elastic modulus due to curing shrinkage of photoreactive curable resin There was a case where the photoreactive resin peeled off.

  An object of the present invention is to provide a method for producing a multilayer optical recording medium that can produce an optical recording medium with high productivity. Another object of the present invention is to provide a manufacturing method capable of producing a reliable optical recording medium.

According to the present invention, as a first aspect, a multilayer having two or more information recording layers provided with a pattern comprising pits constituting a plurality of information recording tracks or pits constituting a plurality of information recording tracks or guide grooves An optical recording medium manufacturing method comprising:
Forming a first resin layer on which a first pattern is formed on a support substrate;
Forming a first information recording layer on the first pattern forming surface of the first resin layer;
Forming a second information recording layer on the second pattern formation surface on the base substrate;
Bonding the support substrate and the base substrate through a second resin layer with the first pattern formation surface side and the second pattern formation surface side facing each other;
A step of peeling the support substrate;
The first information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium is provided in which the glass transition point of the resin of the first resin layer is higher than the glass transition point of the resin of the second resin layer.

According to the present invention, as a second aspect, there is provided a method for producing a multilayer optical recording medium having two or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks. ,
Forming a first resin layer having a first pattern forming surface and a second pattern forming surface on the lower surface and the upper surface, respectively, on the support substrate;
Forming a first information recording layer on the second pattern formation surface;
The second pattern forming surface side of the support substrate and the base substrate are opposed to each other and bonded together via a second resin layer;
Peeling the support substrate;
Forming a second information recording layer on the first pattern formation surface of the first resin layer;
The second information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium is provided in which the glass transition point of the resin of the first resin layer is higher than the glass transition point of the resin of the second resin layer.

  According to the invention, in the second aspect, the method further includes forming a resin protective layer on the second information recording layer formed on the second pattern forming surface, and the resin of the first resin layer. A method for producing a multilayer optical recording medium is provided in which the glass transition point is higher than the glass transition temperature of the resin of the second resin layer and the glass transition point of the resin of the resin protective layer.

According to the present invention, as a third aspect, there is provided a method for producing a multilayer optical recording medium having two or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks. ,
Applying a first photoreactive curable resin on the transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern forming surface;
Transferring and forming a second pattern from the second stamper on the base substrate;
Forming a second information recording layer on the second pattern forming surface of the base substrate;
Applying a second photoreactive curable resin to the pattern forming surface side of either the first pattern or the second pattern;
The transparent support substrate and the base substrate are overlapped with each other through the second photoreactive curable resin so that the first pattern formation surface side and the second pattern formation surface side face each other, and light is transmitted from the transparent support substrate direction. Irradiating and curing and bonding the second photoreactive curable resin;
Having the step of peeling the transparent support substrate,
The first information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium is provided in which the glass transition point of the first photoreactive curable resin is higher than the glass transition point of the second photoreactive curable resin.

According to the present invention, as a fourth aspect, there is provided a method for producing a multilayer optical recording medium having two or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks. ,
Applying a first photoreactive curable resin on the transparent support substrate on which the first pattern is formed;
The first photoreactive curable resin is applied to the transparent support substrate on which the first pattern is formed and the stamper on which the second pattern is formed so that the first pattern formation surface and the second pattern formation surface are opposed to each other. The first photoreactive curable resin is cured by irradiating light from the transparent support substrate direction, and transferring the first and second patterns;
Peeling the stamper;
Forming a first information recording layer on the second pattern forming surface of the first photoreactive curable resin;
A step of facing the second pattern forming surface and the base transparent substrate, and bonding the transparent support substrate and the base transparent substrate through a second photoreactive curable resin;
Peeling the transparent support substrate;
Forming a second information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a third photoreactive curable resin to the first pattern forming surface on which the second information recording layer is formed;
Irradiating and curing the third photoreactive curable resin on the first pattern forming surface to form a resin protective layer made of the cured third photoreactive curable resin;
The second information recording layer is a translucent layer that transmits the recording light beam,
Method for producing multilayer optical recording medium, wherein glass transition point of first photoreactive curable resin is higher than glass transition point of second photoreactive curable resin and glass transition point of third photoreactive curable resin Is provided.

Moreover, the present invention provides, as a fifth aspect, a method for producing a multilayer optical recording medium having four or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Applying a first photoreactive curable resin on the transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a second photoreactive curable resin on the first pattern forming surface on which the first information recording layer is formed;
Transferring the second pattern from the second stamper onto the second photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the second photoreactive curable resin;
Forming a second information recording layer on the second pattern formation surface of the second photoreactive curable resin;
Applying a third photoreactive curable resin on the second pattern forming surface on which the second information recording layer is formed;
Transferring the third pattern from the third stamper onto the third photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the third photoreactive curable resin;
Forming a third information recording layer on the third pattern formation surface of the third photoreactive curable resin;
Transferring and forming a fourth pattern from the fourth stamper on the base substrate;
Forming a fourth information recording layer on a fourth pattern formation surface of the base substrate;
Applying a fourth photoreactive curable resin to the pattern forming surface side of either the third pattern or the fourth pattern;
3rd pattern formation surface side and 4th pattern formation surface side are made to oppose, the said transparent support substrate and the said base substrate are piled up via 4th photoreactive hardening resin, and light is irradiated from a transparent support substrate direction And curing and bonding the fourth photoreactive curable resin;
Having the step of peeling the transparent support substrate,
The first, second and third information recording layers are translucent layers that transmit the recording light beam,
The glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, the glass transition point of the third photoreactive curable resin is Tg3, and the fourth photoreaction. When the glass transition point of the thermosetting resin is Tg4, the following relationship:
Tg3 ≧ Tg2>Tg1> Tg4
A multilayer optical recording medium manufacturing method that satisfies the above is provided.

According to the present invention, as a sixth aspect, there is provided a method for producing a multilayer optical recording medium having four or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks. ,
Applying a first photoreactive curable resin on the first transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the first transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a second photoreactive curable resin on the first pattern forming surface on which the first information recording layer is formed;
Transferring the second pattern from the second stamper onto the second photoreactive curable resin and irradiating light from the first transparent support substrate direction to cure the second photoreactive curable resin;
Forming a second information recording layer on the second pattern formation surface of the second photoreactive curable resin;
Applying a third photoreactive curable resin on the second transparent support substrate on which the third pattern is formed or on the third stamper on which the fourth pattern is formed;
The second transparent support substrate and the third stamper are overlapped with each other through the third photoreactive curable resin with the third pattern formation surface side and the fourth pattern formation surface side facing each other, and the second transparent The third photoreactive curable resin is cured by irradiating light from the support substrate direction, and the third pattern and the fourth pattern are formed on the lower surface of the cured third photoreactive curable resin layer. A transfer process;
Peeling the third stamper;
Forming a third information recording layer on the fourth pattern formation surface;
The 4th pattern formation surface in which the 3rd information recording layer was formed, and the 3rd transparent support substrate are made to oppose, and the 2nd transparent support substrate and the 3rd transparent support are interposed via the 4th photoreactive hardening resin. A step of bonding the substrate,
Peeling the second transparent support substrate;
Forming a fourth information recording layer on the third pattern formation surface of the third photoreactive curable resin;
Applying a fifth photoreactive curable resin to the pattern forming surface of either the second pattern or the third pattern;
The first transparent support substrate and the third transparent support substrate are overlapped with each other through the fifth photoreactive curable resin with the second pattern formation surface side and the third pattern formation surface side facing each other. Irradiating light from the substrate direction to cure and bond the fifth photoreactive curable resin;
Having a step of peeling the first transparent support substrate;
The first, second and fourth information recording layers are translucent layers that transmit the recording light beam,
The glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, the glass transition point of the third photoreactive curable resin is Tg3, and the fourth photoreaction. When the glass transition point of the thermosetting resin is Tg4, the following relationship:
Tg2>Tg1> Tg4 and Tg3> Tg4
A multilayer optical recording medium manufacturing method that satisfies the above is provided.

According to the invention, in the sixth aspect, the glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, and the third photoreactive property. When the glass transition point of the cured resin is Tg3, the glass transition point of the fourth photoreactive cured resin is Tg4, and the glass transition point of the fifth photoreactive cured resin is Tg5, the following relationship:
Tg2>Tg1> Tg4 ≧ Tg5 and Tg3> Tg4
A multilayer optical recording medium manufacturing method that satisfies the above is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the multilayer optical recording medium which can manufacture an optical recording medium with sufficient productivity can be provided. In addition, a reliable optical recording medium can be provided.

  In the third aspect, it is advantageous that the thickness of the layer made of the first photoreactive curable resin applied on the transparent support substrate is larger than the thickness of the layer made of the second photoreactive curable resin. Is.

  In the third aspect, it is effective that the transparent support substrate is made of a transparent material that is not deteriorated by the irradiation light.

  In the third aspect, it is effective that the step of transferring the second pattern on the base substrate from the second stamper is formed by injection molding.

  In the third aspect, it is effective that the first stamper and the second stamper are made of metal.

In the fourth aspect, the step of bonding the transparent support substrate and the base transparent substrate comprises:
Applying a second photoreactive curable resin to either the second pattern forming surface side or the base transparent substrate side;
The second pattern formation surface side and the base transparent substrate are opposed to each other, the transparent support substrate and the base transparent substrate are overlapped via a second photoreactive curable resin, and light is irradiated from the direction of the base transparent substrate. It is effective to consist of the process of hardening 2 photoreactive cured resin.

  In the fourth aspect, the thickness of the layer made of the third photoreactive curable resin may be larger than the thickness of the layer made of the first photoreactive curable resin applied on the transparent support substrate. It is effective.

  In the fourth aspect, it is effective that the first pattern of the transparent support substrate is formed by injection molding.

  In the fourth aspect, it is effective to reuse the used transparent support substrate that has been irradiated with light in the manufacturing process performed previously as the base substrate.

  In the fourth aspect, it is effective that the stamper is made of metal.

  In the fifth aspect, the thickness of the first photoreactive curable resin includes the thickness of the second photoreactive curable resin, the third constant thickness of the third photoreactive curable resin, and the fourth thickness. It is effective to be thicker than the thickness of the photoreactive curable resin.

  In the fifth aspect, it is effective that the transparent support substrate is made of a transparent material that is not deteriorated by the irradiation light.

  In the fifth aspect, it is effective that the fourth pattern of the base substrate is formed by injection molding.

  In the fifth aspect, it is effective that the first, second, third and fourth stampers are made of metal.

  In the sixth embodiment, the fourth pattern forming surface on which the third information recording layer is formed and the third transparent support substrate are opposed to each other, and the second transparent support substrate and the third transparent support substrate are bonded. It is effective that the step of combining comprises the following steps. A step of applying a fourth photoreactive curable resin to either the fourth pattern forming surface side or the third transparent support substrate. The fourth pattern formation surface side and the third transparent support substrate are opposed to each other, and the second transparent support substrate and the third transparent support substrate are overlapped with each other via the fourth photoreactive curable resin, A step of irradiating light from the transparent substrate direction to cure and bond the fourth photoreactive curable resin.

  In the sixth embodiment, the thickness of the first photoreactive curable resin is the thickness of the second photoreactive curable resin, the thickness of the third photocurable curable resin, and the fifth photoreactive resin. It is effective to be thicker than the thickness of the curable resin.

  In the sixth embodiment, it is effective that the first transparent support substrate is made of a transparent material that does not deteriorate due to the irradiation light.

  In the sixth embodiment, it is effective that the third pattern of the second transparent support substrate is formed by injection molding.

  Moreover, in the said 6th form, it is effective to reuse the used said 2nd transparent support substrate irradiated with light in the manufacturing process performed previously as a 3rd transparent support substrate.

  In the sixth embodiment, it is effective that the first, second and third stampers are made of metal.

  In the first, second, third and fourth aspects, the glass transition point of the resin of the first resin layer is in the range of 70 ° C. to 200 ° C., and the glass transition point of the resin of the second resin layer is It is effective to be in the range of 25 ° C to 150 ° C. It is more effective that the glass transition point of the resin of the second resin layer is in the range of 25 ° C to 100 ° C.

  Moreover, in the said 2nd and 4th aspect, when it has a resin protective layer, it is effective that the glass transition point of resin of a 1st resin layer is higher than the glass transition point of resin of the said resin protective layer. The glass transition point of the resin of the resin protective layer is effectively in the range of 25 ° C. to 150 ° C., and more preferably in the range of 25 ° C. to 100 ° C.

  In the fifth aspect, the glass transition points of the first, second, and third photoreactive curable resins are in the range of 70 ° C. to 200 ° C., and the glass transition point of the fourth photoreactive curable resin is 25. It is effective to be in the range of from 150 ° C to 150 ° C. It is more effective that the glass transition point of the fourth photoreactive curable resin is in the range of 25 ° C to 100 ° C.

  In the sixth aspect, the glass transition points of the first, second and third photoreactive curable resins are in the range of 70 ° C. to 200 ° C., and the glass transition of the fourth and fifth photoreactive curable resins. It is effective that the point is in the range of 25 ° C to 150 ° C. It is more effective that the glass transition points of the fourth and fifth photoreactive curable resins are in the range of 25 ° C to 100 ° C.

  In each of the above embodiments, it is effective that the elastic modulus of the resin and the photoreactive curable resin is in the range of 0.5 MP to 2.5 GPa at 23 ° C., and more preferably in the range of 1 MPa to 2 GPa. It is effective.

  The glass transition point can be measured by differential scanning calorimetry (DSC) or differential thermal analysis (DTA) according to JIS standard K7121 (plastic transition temperature measurement method). The glass transition point can also be measured by JIS standard K7244 (a test method for dynamic mechanical properties of plastics). The elastic modulus can be measured according to the KJIS standard K7244.

  The photoreactive curable resin can be appropriately selected from known resins such as epoxy resins, urethane resins, acrylate resins, and silicone resins, and known resins known as 2p (Photopolymer) resins.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1
A first embodiment of a method for producing a two-layer optical recording medium according to the present invention will be described with reference to FIGS. 1A and 1B. The optical recording medium obtained by the manufacturing method shown in FIGS. 1A and 1B has two information recording layers (L0 layer and L1 layer). 1A and 1B show one half of a rotationally symmetric disk-shaped cross-sectional view having a central hole, and the central hole of the substrate and stamper is omitted.

  In FIG. 1A (1), a photoreactive curable resin for a cover sheet (resin protective layer) for forming a cover sheet provided on an L1 layer recording film on a glass substrate (transparent support substrate) 1 (hereinafter “ 2) (denoted as “2p resin”). Typically, the glass substrate 1 has a thickness of 1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm. The cover sheet 2p resin 2 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (first constant thickness). did. The thickness of this resin is, for example, 75 μm. An epoxy acrylate 2p resin was used as the 2p resin for the cover sheet, the glass transition point after curing was 80 ° C., and the elastic modulus was 1.0 GPa at 23 ° C.

  In FIG. 1A (2), a metal stamper A (first stamper) 3 in which an information pattern (first pattern) 13 of the L1 layer is previously formed on the cover sheet 2p resin 2 is formed in the center hole (FIG. (Not shown) is aligned with the glass substrate 1 and superimposed. Thereafter, UV light is irradiated from the UV light source 5 through the glass substrate 1, and the cover sheet 2p resin 2 is cured. The cover sheet 2p resin 2 may be overlaid on the glass substrate 1 after being applied to the stamper A3. The cover sheet 2p resin 2 is a single layer. However, in order to improve physical protection and moisture permeability, and to adjust the thickness by adjusting the film thickness and shrinking by curing, the resin layer or inorganic material is removed after the glass substrate is peeled off in the subsequent process. In some cases, a resin layer containing bismuth is formed.

  In FIG. 1A (3), after the cover sheet 2p resin 2 is cured, the stamper A3 is peeled off, and an information pattern 13 (pits and guide grooves) of the L1 layer is formed on the glass substrate. The peeled metal stamper A does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly. In addition, the peelability from a metal stamper was favorable by using 2p resin with a high glass transition point. The glass substrate can be subjected to known surface treatments such as plasma, UV ozone, and silane coupling agent coating to improve the adhesion between the glass substrate and the 2p resin. Also, the metal stamper can be subjected to a known surface treatment such as fluorine or silicone coating to improve the peelability. Furthermore, the 2p resin can contain a silane coupling agent to improve the adhesion only on the glass substrate side, thereby assisting the peelability of the stamper. However, the known surface treatment technique alone causes problems in terms of the peelability of the glass substrate in the subsequent process, the transferability of the stamper information pattern, and the adhesion between the recording film and the 2p resin. In the present invention, the problem is solved by adjusting the elastic modulus according to the glass transition point of the 2p resin and the 2p resin used in the subsequent step.

  In FIG. 1A (4), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer. The L1 layer recording film 14 is a translucent film. The configuration of the L1 layer will be described in detail later with reference to FIG.

  In FIG. 1B (5), a PC substrate (base substrate) 15 is a polycarbonate (PC) substrate that is injection-molded using an injection molding stamper (second stamper) 21. An L0 layer information pattern (second pattern) 16 (pits and guide grooves) is formed on the substrate. Typically, the PC board 15 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm.

  In FIG. 1B (6), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer. The L0 layer recording film 17 is typically configured to include a reflective film that does not transmit light or a reflective film. The configuration of the L0 layer will be described in detail later with reference to FIG.

  In FIG. 1B (7), the 2p resin 7 for the intermediate layer 1 for forming the intermediate layer 1 between the L0 layer recording film 17 and the L1 layer provided on the L0 layer recording film 17 is formed on the L0 layer. Applied. The 2p resin 7 for the intermediate layer 1 is dropped in an annular shape on the inner peripheral side of the PC board 15 having a center hole (not shown), and is spun off by rotating the PC board to obtain a uniform thickness (second constant thickness). It was. The thickness of this resin is, for example, 25 μm. As the 2p resin for the intermediate layer 1, a urethane acrylate-based 2p resin was used. The glass transition point after curing was 25 ° C., and the elastic modulus was 1.0 MPa at 23 ° C.

  In FIG. 1B (8), the laminated body after the process shown in FIG. 1A (4) is aligned and overlapped on the 2p resin 7 for the intermediate layer 1 using the center hole (not shown) of the glass substrate 1. The Thereafter, ultraviolet light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 7 for the intermediate layer 1 is cured. At this time, the L1 layer recording film 14 needs to be translucent at the wavelength of the UV light beam, and preferably has a transmittance of 20% or more. Further, when a visible light source is used instead of a UV light source and a resin that cures is selected at the wavelength of the visible light beam so that the transmittance of the L1 layer recording film 14 is 50% or more, the curing time can be shortened. . The 2p resin 7 for the intermediate layer 1 may be applied on the L1 layer recording film 14 and then overlapped with the L0 layer recording film 17 on the PC substrate 15.

  In FIG. 1B (9), after the 2p resin 7 for the intermediate layer 1 is cured, the glass substrate 1 is peeled off, and the two-layer optical recording medium in the present invention is completed.

  Next, the configuration of the L0 layer recording film 17 and the L1 layer recording film 14 will be described in detail with reference to FIG. FIG. 2 is a cross-sectional view of the completed two-layer optical recording medium of the present invention. On the PC substrate 15, the L0 layer 17 and the L1 layer 14 which are recording films are arranged via the intermediate layer 7 from the PC substrate side, and the cover layer 2 covers the L1 layer. The light beam for recording / reproduction enters the optical recording medium from the direction of the arrow 23.

  The recording layers of the L0 layer 17 and the L1 layer 14 will be described as an example. Each recording film may be a write-once type, a rewritable type, or a combination thereof.

  The L1 layer recording film 14 on the information pattern 13 of the L1 layer formed in the step shown in FIG. 1A (4) is formed by the following procedure as shown in FIG. First, an L1 dielectric layer 34 is formed on the information pattern 13 of the L1 layer formed by guide grooves and pits, and an L1 interface layer 33, an L1 recording layer 32, and an L1 interface layer as necessary. 31, the L1 reflection layer 30, and the L1 high refractive index layer 29 are sequentially formed as necessary. That is, the dielectric layer, the recording layer, and the reflective layer are formed in this order on the information pattern.

  On the other hand, the L0 layer recording film 17 on the information pattern 16 of the L0 layer formed in the step shown in FIG. 1B (6) is formed by the following procedure as shown in FIG. First, the L0 reflection layer 24 is formed on the information pattern 16 of the L0 layer formed by guide grooves and pits. The L0 interface layer 25, the L0 recording layer 26, and the L0 interface layer 27 as necessary. , L0 dielectric layer 28 is sequentially deposited. That is, the information layer is formed in the order of the reflective layer, the recording layer, and the dielectric layer in the reverse order to the L1 layer.

  In the conventional two-layer optical recording medium, all the layers are formed in the order of the reflective layer, the recording layer, and the dielectric layer.

  By employing the optical recording medium manufacturing method of the present invention, it is possible to manufacture an inexpensive two-layer optical recording medium without using a transparent stamper that is difficult to reuse, which was a factor of high cost. It became.

  Further, by making the glass transition point of the cover sheet resin higher than the glass transition point of the intermediate layer resin, the glass substrate can be easily peeled while maintaining the transferability of the information pattern of the stamper. That is, since the glass transition point of the 2p resin for the intermediate layer is low, the PC substrate, the L0 layer recording film, and the intermediate layer are firmly formed, and the intermediate layer, the L1 recording film, and the cover sheet resin are firmly formed. Become. As a result, only the glass adhered to the cover sheet layer having a high glass transition point can be easily peeled off. In addition, although stress is generated as the cover sheet resin cures and shrinks, the stress generated as the intermediate layer cures is small and firmly adhered to the substrate, so TILT occurs due to changes in temperature and humidity, drop impact, etc. No peeling of the resin layer occurred.

[Embodiment 2]
A second embodiment of the method for producing a two-layer optical recording medium according to the present invention will be described with reference to FIGS. 3A, 3B, and 3C. The optical recording medium obtained by the manufacturing method shown in FIGS. 3A, 3B, and 3C has two information recording layers (L0 layer and L1 layer). 3A, 3B, and 3C show one half of a rotationally symmetric disk-like cross-sectional view having a central hole, as in FIGS. 1A and 1B, and the central holes of the substrate and stamper are omitted. Moreover, the same code | symbol is used for the member similar to FIG. 1A and FIG. 1B.

  In FIG. 3A (1), a transparent stamper (transparent support substrate) 19 made of polycarbonate (PC) is a transparent stamper that is injection-molded using an injection molding stamper B22. On the transparent stamper 19, an information pattern (first pattern) 13 (pits and guide grooves) of the L1 layer is formed. Typically, the transparent stamper 19 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm.

  In FIG. 3A (2), 2p resin (photoreactive curable resin) 7 for the intermediate layer 1 for forming the intermediate layer 1 between the L0 layer and the L1 layer is applied. The 2p resin 7 for the intermediate layer 1 is dropped in an annular shape on the inner peripheral side of a transparent stamper 19 having a center hole (not shown), and the transparent stamper is rotated and shaken off to have a uniform thickness (first constant thickness). It was. The thickness of this resin is, for example, 25 μm. As the 2p resin for the intermediate layer 1, an epoxy acrylate type 2p resin was used. The glass transition point after curing was 200 ° C., and the elastic modulus was 2.0 GPa at 23 ° C.

  3A (3), the metal stamper A ′ (metal stamper) 3 in which the information pattern (second pattern) 16 of the L0 layer is previously formed on the 2p resin 7 for the intermediate layer 1 is formed in the central hole (FIG. 3A). (Not shown) and aligned with the transparent stamper 19. Thereafter, UV light is irradiated from the UV light source 5 through the transparent stamper 19, and the 2p resin 7 for the intermediate layer 1 is cured. The 2p resin 7 for the intermediate layer 1 may be superimposed on the transparent stamper 19 after being applied to the metal stamper A′3.

  3A (4), after the 2p resin 7 for the intermediate layer 1 is cured, the metal stamper A'3 is peeled off, and the information pattern 16 of the L0 layer is formed on the transparent stamper 19. The peeled metal stamper A'3 does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 3B (5), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer. The L0 layer recording film 17 typically includes a reflective film that does not transmit light or a reflective film. The configuration of the L0 layer is the same as that shown in FIG. 2 of the first embodiment, but the order of forming each layer constituting the L0 layer recording film is reverse to that shown in FIG.

  In FIG. 3B (6), the PC board bonding 2p resin 20 for bonding the L0 layer and the PC board is applied. The PC board bonding 2p resin 20 was dropped in an annular shape on the inner peripheral side of a transparent stamper 19 having a center hole (not shown), and the transparent stamper was rotated to shake off to a uniform thickness. The resin thickness is, for example, 10 to 20 μm, but it is only necessary to have a constant thickness. The PC board bonding 2p resin 20 does not need to consider transferability, and only needs to satisfy releasability and thickness accuracy. A urethane acrylate-based 2p resin was used as the PC substrate bonding 2p resin. The glass transition point after curing was 60 ° C., and the elastic modulus was 10.0 MPa at 23 ° C.

  In FIG. 3B (7), a PC substrate (base transparent substrate) 15 is formed in the center hole (not shown) on the transparent stamper 19 on which the 2p resin 7 for the intermediate layer 1, the L0 layer recording film 17 and the 2p resin 20 for adhesion are formed. )) And are overlaid. Thereafter, UV light is irradiated from the UV light source 5 through the PC board 15, and the PC board bonding 2p resin 20 is cured. The PC board 15 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm. The PC board 15 can use the used transparent stamper 19. Even if optical characteristics such as transmittance are slightly deteriorated by UV irradiation, there is no problem because the light flux for recording / reproduction does not pass through the PC board 15. Thereby, since the used transparent stamper 19 is not discarded, the cost can be reduced.

  In FIG. 3B (8), after the 2p resin 20 for bonding the PC board is cured, the transparent stamper 19 is peeled off, and the information pattern (first pattern) 13 of the L1 layer is formed on the PC board 15. The peeled transparent stamper 19 can be used as a substrate of a multilayer optical recording medium to be manufactured next, as described with reference to FIG. 3B (7).

  In FIG. 3C (9), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer. The L1 layer recording film 14 is a translucent film. The configuration of the L1 layer is the same as that shown in FIG. 2 of the first embodiment, but the order of forming each layer constituting the L1 layer recording film is reverse to that shown in FIG.

  3C (10), the cover sheet 2p resin 2 for forming a cover sheet (resin protective layer) provided on the L1 layer recording film 14 is similarly applied. The cover sheet 2p resin 2 is dropped in an annular shape on the inner peripheral side of the PC board 15 having a center hole (not shown), and the PC board is rotated and shaken to obtain a uniform thickness (second constant thickness). did. The thickness of this resin is, for example, 75 μm. As the 2p resin for the cover sheet, a urethane acrylate-based 2p resin was used, the glass transition point after curing was 60 ° C., and the elastic modulus was 10.0 MPa at 23 ° C. Similarly to Embodiment 1, a resin layer containing a resin layer and an inorganic material can be formed on the cover sheet, and the thickness of the cover sheet and the resin layer containing the resin and the inorganic material is adjusted to 75 μm. You can also.

  In FIG. 3C (11), the cover sheet 2p resin 2 is cured, and the two-layered optical recording medium of the present invention is completed.

  The recording film 17 of the L0 layer and the recording film 14 of the L1 layer will be described by taking a recording type as an example. Each recording film may be a write-once type, a rewritable type, or a combination thereof.

  As described with reference to FIG. 3B (5), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer by the following procedure. First, the L0 dielectric layer 28 is formed on the information pattern 16 of the L0 layer formed by guide grooves and pits. The L0 interface layer 27, the L0 recording layer 26, and the L0 interface layer as necessary. 25, the L0 reflection layer 23 is sequentially formed. That is, a film is formed on the information pattern in the order of dielectric layer-recording layer-reflection layer.

  On the other hand, as described with reference to FIG. 3C (9), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer by the following procedure. First, an L1 high refractive index layer 29 and an L1 reflective layer 30 are formed on the information pattern 13 of the L1 layer formed by guide grooves and pits, if necessary, and the L1 interface layer 31 and L1 recording are performed as necessary. A layer 32, and optionally an L1 interface layer 33 and an L1 dielectric layer 34 are sequentially formed. In other words, on the information pattern, the reflective layer, the recording layer, and the dielectric layer are formed in the reverse order to the L0 layer.

  In the conventional two-layer optical recording medium, all the layers are formed in the order of the reflective layer, the recording layer, and the dielectric layer.

  By adopting the optical recording medium manufacturing method of the present invention, an inexpensive two-layer optical recording medium can be manufactured by diverting a transparent stamper that is difficult to reuse as a substrate. It has become possible.

  Further, the exfoliation property of the stamper was improved by increasing the glass transition point of the resin layer 7 forming the L0 layer pattern and the L1 layer pattern. This is considered to be because the higher the glass transition point, the higher the rigidity, and as a result, the stress generated along with the curing shrinkage is accumulated and contributes to the peelability of the stamper. Further, since the resin layer 7 forming the L0 layer pattern and the L1 layer pattern has a thickness of about 25 μm and the stress of the other resin layers formed is considered to be low, the deterioration of TILT and the No problems such as peeling occurred. Further, since the glass transition point of the resin layer 7 to which the information pattern is transferred is high, the information pattern shape is not deformed even when the temperature rises in the recording film formation. This enabled us to improve productivity.

[Embodiment 3]
A first embodiment of a method for manufacturing a four-layer optical recording medium according to the present invention will be described with reference to FIGS. 4A, 4B, 4C, and 4D. The optical recording medium obtained by the manufacturing method shown in FIGS. 4A, 4B, 4C, and 4D has four information recording layers (L0, L1, L2, and L3 layers). 4A, 4B, 4C, and 4D show one half of a rotationally symmetric disk-shaped cross-sectional view having a central hole, and the central holes of the substrate and stamper are omitted. Moreover, the same code | symbol is used for the member similar to FIG. 1A and FIG. 1B.

  4A (1), a 2p resin (photoreactive curable resin) for a cover sheet for forming a cover sheet (resin protective layer) provided on an L3 layer recording film on a glass substrate (transparent support substrate) 1. 2 is applied. Typically, the glass substrate 1 has a thickness of 1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm. The cover sheet 2p resin 2 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (first constant thickness). did. The thickness of this resin is, for example, 70 μm. An epoxy acrylate type 2p resin was used as the 2p resin for the cover sheet, the glass transition point after curing was 70 ° C., and the elastic modulus was 500 MPa at 23 ° C.

  4A (2), a metal stamper A (first stamper) 3 in which an information pattern (first pattern) of the L3 layer is formed in advance on the cover sheet 2p resin 2 is a central hole (not shown). And the glass substrate 1 are aligned and overlapped. Thereafter, UV light is irradiated from the UV light source 5 through the glass substrate 1, and the cover sheet 2p resin 2 is cured. The cover sheet 2p resin 2 may be overlaid on the glass substrate 1 after being applied to the stamper A3. For simplicity, the cover sheet 2p resin 2 is a single layer. However, as in the first embodiment, a resin layer or a resin layer containing an inorganic material is formed on the cover sheet 2p resin after the glass substrate is peeled off in a later step. Sometimes formed.

  4A (3), after the cover sheet 2p resin 2 is cured, the stamper A3 is peeled off, and an information pattern 4 (pits or guide grooves) of the L3 layer is formed on the glass substrate. The peeled metal stamper A does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  4A (4), an L3 layer recording film 6 is formed on the information pattern 4 of the L3 layer. The L3 layer recording film 6 is a translucent film.

  In FIG. 4B (5), 2p resin 7 for intermediate layer 1 is applied on L3 layer recording film 6 to form intermediate layer 1 between L3 layer and L2 layer provided on this L3 layer. The The 2p resin 7 for the intermediate layer 1 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (second constant thickness). It was. The thickness of this resin is, for example, 10 μm. An epoxy acrylate type 2p resin was used as the 2p resin for the intermediate layer 1, and its glass transition point after curing was 120 ° C. and the elastic modulus was 1.2 GPa.

  4B (6), the metal stamper B (second stamper) 8 in which the information pattern (second pattern) of the L2 layer is formed in advance on the 2p resin 7 for the intermediate layer 1 has a central hole (see FIG. 4B). (Not shown) is aligned with the glass substrate 1 and superimposed. Thereafter, ultraviolet light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 7 for the intermediate layer 1 is cured. The 2p resin 7 for the intermediate layer 1 may be superimposed on the glass substrate 1 after being applied to the stamper B8.

  4B (7), after the 2p resin 7 for the intermediate layer 1 is cured, the stamper B8 is peeled off, and the information pattern 9 (pits and guide grooves) of the L2 layer is formed on the resin layer on the L3 layer recording film 6. The The peeled metal stamper B8 does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 4B (8), the L2 layer recording film 10 is formed on the information pattern 9 of the L2 layer. The L2 layer recording film 10 is a translucent film.

  4C (9), the 2p resin 11 for the intermediate layer 2 for forming the intermediate layer 2 between the L2 layer and the L1 layer provided on the L2 layer is applied on the L2 layer recording film 10. The The 2p resin 11 for the intermediate layer 2 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (third constant thickness). It was. The resin thickness is, for example, 15 μm. As the 2p resin for the intermediate layer 2, an epoxy acrylate type 2p resin was used. The glass transition point after curing was 140 ° C., and the elastic modulus was 1.5 GPa.

  In FIG. 4C (10), the metal stamper C (third stamper) 12 in which the information pattern (third pattern) of the L1 layer is formed in advance on the 2p resin 11 for the intermediate layer 2 has a central hole (see FIG. 4C). (Not shown) is aligned with the glass substrate 1 and superimposed. Thereafter, UV light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 11 for the intermediate layer 2 is cured. The 2p resin 11 for the intermediate layer 2 may be superimposed on the glass substrate 1 after being applied to the stamper C12.

  4C (11), after the 2p resin 11 for the intermediate layer 2 is cured, the stamper C12 is peeled off, and the information pattern 13 (pits and guide grooves) of the L1 layer is formed on the resin layer on the L2 layer recording film 10. The The peeled metal stamper C does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 4C (12), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer. The L1 layer recording film 14 is a translucent film.

  In FIG. 4D (13), a PC substrate (base transparent substrate) 15 is a polycarbonate (PC) substrate that is injection-molded using an injection molding stamper (fourth stamper) 21. An L0 layer information pattern (fourth pattern) 16 (pits and guide grooves) is formed on the substrate. Typically, the PC board 15 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm.

  In FIG. 4D (14), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer. The L0 layer recording film 17 is typically configured to include a reflective film that does not transmit light or a reflective film.

  In FIG. 4D (15), 2p resin 18 for intermediate layer 3 is applied on L0 layer recording film 17 to form intermediate layer 3 between L0 layer and L1 layer formed on this L0 layer. Is done. The 2p resin 18 for the intermediate layer 3 is dropped in an annular shape on the inner peripheral side of the PC board 15 having a center hole (not shown), and is spun off by rotating the PC board to obtain a uniform thickness (fourth constant thickness). It was. The thickness of this resin is, for example, 10 μm. As the 2p resin for the intermediate layer 3, a urethane acrylate-based 2p resin was used. The glass transition point after curing was 30 ° C., and the elastic modulus was 1.0 MPa at 23 ° C.

  In FIG. 4D (16), the laminated body after the process shown in FIG. 4C (12) is aligned and overlapped on the 2p resin 18 for the intermediate layer 3 using the center hole (not shown) of the glass substrate 1. The Thereafter, ultraviolet light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 18 for the intermediate layer 3 is cured. At this time, the L1 layer recording film 14, the L2 layer recording film 10 and the L3 layer recording film 6 need to be translucent at the wavelength of the UV light flux, and desirably the integrated transmittance is 20% or more. Further, a visible light source is used in place of the UV light source so that the integrated transmittance of the L1 layer recording film 14, the L2 layer recording film 10 and the L3 layer recording film 6 is 50% or more, and curing is performed at the wavelength of the visible light beam. When the resin to be selected is selected, the curing time can be shortened. The 2p resin 18 for the intermediate layer 3 may be applied to the L1 layer recording film 14 and then overlapped with the L0 layer recording film 17 on the PC substrate 15.

  In FIG. 4D (17), after the 2p resin 18 for the intermediate layer 3 is cured, the glass substrate 1 is peeled, and the optical recording medium having a four-layer structure in the present invention is completed.

  FIG. 4D (17) shows a sectional view of the completed four-layer type optical recording medium of the present embodiment. Four recording layers L0 (17), L1 (14), L2 (10), and L3 (6) from the PC substrate side on the PC substrate 15 are intermediate layers 3 (18) between the L0 layer and the L1 layer, respectively. The intermediate layer 2 (11) is disposed between the L1 layer and the L2 layer, and the intermediate layer 1 (7) is disposed between the L2 layer and the L3 layer. The cover layer 2 covers the L3 layer. A light beam for recording / reproduction enters the medium from the direction of the cover layer 2.

  As described in FIGS. 4A (4), 4B (8) and 4C (12), the L1-L3 layer recording films 14, 10 and 6 are formed on the information patterns of the L1-L3 layers in the following procedure, respectively. Be filmed. First, a dielectric layer is formed on the information patterns 13, 9, and 4 of the L1 to L3 layers formed by guide grooves and pits, and an interface layer, a recording layer, and an interface layer as necessary. A reflective layer and, if necessary, a high refractive index layer are sequentially formed. That is, a film is formed on the information pattern in the order of dielectric layer-recording layer-reflection layer.

  On the other hand, as described in FIG. 4D (14), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer by the following procedure. First, a reflective layer is formed on the information pattern 16 of the L0 layer formed by guide grooves and pits, and an interface layer, a recording layer, and an interface layer and a dielectric layer are sequentially formed as necessary. Is done. That is, the film is formed on the information pattern in the order of the reflective layer, the recording layer, and the dielectric layer in the reverse order of the L1 to L3 layers.

  By employing the optical recording medium manufacturing method of the present invention, it is possible to manufacture an inexpensive four-layer optical recording medium without using a transparent stamper that is difficult to reuse, which was a factor of high cost. It became.

  The glass transition point Tg of 2p resin is [Tg3 of 2p resin for intermediate layer 2] ≧ [Tg2 of 2p resin for intermediate layer 1]> [Tg1 of 2p resin for cover sheet]> [Tg4 of 2p resin for intermediate layer 3] ].

  When the stamper B8 is peeled from the 2p resin 7 for the intermediate layer 1 by Tg2> Tg1, the adhesiveness between the glass substrate 1 and the 2p resin 2 for the cover sheet is high, and the 2p resin 7 for the intermediate layer 1 and the stamper B8 are relatively Adhesive strength at the interface is weak. Further, the 2p resin 7 for the intermediate layer 1 and the 2p resin 2 for the cover sheet are firmly bonded to each other in a region where the recording film on the inner peripheral portion and the outer peripheral portion of the substrate is not formed. As a result, the stamper B could be easily peeled off.

  When the stamper C12 is peeled off from the intermediate layer 2 resin 11, the laminated structure from the glass substrate 1 to the 2p resin 11 for the intermediate layer 2 is firmly formed by Tg3 ≧ Tg2> Tg1, and the intermediate layer 2 relatively The adhesive force at the interface between the 2p resin 11 and the stamper C12 is weak. As a result, the stamper C12 was easily peeled off.

  In the peeling of the glass substrate 1, the adhesive force between the 2p resin 18 for the resin intermediate layer 3 and the PC substrate 15 is the strongest due to Tg1> Tg4, and relatively at the interface between the 2p resin 2 for the cover sheet and the glass substrate 1. Adhesive strength is weak. As a result, the glass substrate 1 can be peeled off.

  The four-layer type optical recording medium manufactured by the manufacturing method of the present embodiment has the problem that even if there is a temperature / humidity change or a drop impact, the deterioration of TILT is suppressed and each resin layer is peeled off. Thus, a highly reliable optical recording medium was obtained.

[Embodiment 4]
A second embodiment of the method for producing a four-layer optical recording medium according to the present invention will be described with reference to FIGS. 5A, 5B, 5C, 5D, and 5E. The optical recording medium obtained by the manufacturing method shown in FIGS. 5A, 5B, 5C, 5D, and 5E has four information recording layers (L0, L1, L2, and L3 layers). 5A, FIG. 5B, FIG. 5C, FIG. 5D and FIG. 5E show one half of a rotationally symmetric disk-shaped cross-sectional view having a center hole, and the center holes of the substrate and stamper are omitted. Moreover, the same code | symbol is used for the member similar to FIG. 1A and FIG. 1B.

  In FIG. 5A (1), 2p for cover sheet (photoreactive curing) for forming a cover sheet (resin protective layer) provided on the L3 layer recording film on glass substrate (first transparent support substrate) 1 Resin) Resin 2 is applied. Typically, the glass substrate 1 has a thickness of 1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm. The cover sheet 2p resin 2 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (first constant thickness). did. The thickness of this resin is, for example, 70 μm. As the 2p resin for the cover sheet, an epoxy acrylate type 2p resin was used, the glass transition point after curing was 80 ° C., and the elastic modulus was 1.0 GPa at 23 ° C.

  5A (2), a metal stamper A (first stamper) 3 in which an information pattern (first pattern) of the L3 layer is formed in advance on the cover sheet 2p resin 2 is a center hole (not shown). And the glass substrate 1 are aligned and overlapped. Thereafter, UV light is irradiated from the UV light source 5 through the glass substrate 1, and the cover sheet 2p resin 2 is cured. The cover sheet 2p resin 2 may be overlaid on the glass substrate 1 after being applied to the stamper A3.

  In FIG. 5A (3), after the cover sheet 2p resin 2 is cured, the stamper A3 is peeled off, and an information pattern 4 (pits and guide grooves) of the L3 layer is formed on the glass substrate. The peeled metal stamper A does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 5A (4), the L3 layer recording film 6 is formed on the information pattern 4 of the L3 layer. The L3 layer recording film 6 is a translucent film.

  In FIG. 5B (5), the 2p resin 7 for the intermediate layer 1 is applied on the L3 layer recording film 6 to form the intermediate layer 1 between the L3 layer and the L2 layer provided on the L3 layer. The The 2p resin 7 for the intermediate layer 1 is dropped in an annular shape on the inner peripheral side of the glass substrate 1 having a center hole (not shown), and the glass substrate is rotated and shaken to obtain a uniform thickness (second constant thickness). It was. The thickness of this resin is, for example, 10 μm. An epoxy acrylate 2p resin was used as the 2p resin for the intermediate layer 1, and the glass transition point after curing was 180 ° C., and the elastic modulus was 1.9 GPa at 23 ° C.

  5B (6), the metal stamper B (second stamper) 8 in which the information pattern (second pattern) of the L2 layer is formed in advance on the 2p resin 7 for the intermediate layer 1 is formed in the central hole (FIG. (Not shown) is aligned with the glass substrate 1 and superimposed. Thereafter, ultraviolet light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 7 for the intermediate layer 1 is cured. The 2p resin 7 for the intermediate layer 1 may be superimposed on the glass substrate 1 after being applied to the stamper B8.

  In FIG. 5B (7), after the 2p resin 7 for the intermediate layer 1 is cured, the stamper B8 is peeled off, and an information pattern 9 (pits and guide grooves) of the L2 layer is formed on the resin layer on the L3 layer recording film 6. The The peeled metal stamper B8 does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 5B (8), the L2 layer recording film 10 is formed on the information pattern 9 of the L2 layer. The L2 layer recording film 10 is a translucent film.

  In FIG. 5C (9), a transparent stamper (second transparent support substrate) 19 made of polycarbonate (PC) is injection-molded using an injection molding stamper 22. On the transparent stamper 19, an information pattern (third pattern) 13 (pits and guide grooves) of the L1 layer is formed. Typically, the transparent stamper 19 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm.

  In FIG. 5C (10), 2p resin 18 for intermediate | middle layer 3 for forming the intermediate | middle layer 3 between L0 layer and L1 layer is apply | coated. The 2p resin 18 for the intermediate layer 3 is dropped in an annular shape on the inner peripheral side of a transparent stamper 19 having a center hole (not shown), and the transparent stamper is rotated and shaken off to obtain a uniform thickness (third constant thickness). It was. The thickness of this resin is, for example, 10 μm. As the 2p resin for the intermediate layer 3, an epoxy acrylate type 2p resin was used. The glass transition point after curing was 170 ° C., and the elastic modulus was 1.8 GPa at 23 ° C.

  5C (11), the metal stamper C (third stamper) 12 in which the information pattern (fourth pattern) 16 of the L0 layer is previously formed on the 2p resin 18 for the intermediate layer 3 is formed in the center hole ( (Not shown) is used to align with the transparent stamper 19 and overlap. Thereafter, ultraviolet light is irradiated from the UV light source 5 through the transparent stamper 19, and the 2p resin 18 for the intermediate layer 3 is cured. The 2p resin 18 for the intermediate layer 3 may be superimposed on the transparent stamper 19 after being applied to the stamper C12.

  In FIG. 5C (12), after the 2p resin 18 for the intermediate layer 3 is cured, the stamper C12 is peeled off, and the information pattern 16 of the L0 layer is formed on the resin layer on the transparent stamper. The peeled metal stamper C12 does not deteriorate even when irradiated with a UV light beam, and can be used repeatedly.

  In FIG. 5C (13), the L0 layer recording film 17 is formed on the information pattern 16 of the L0 layer. The L0 layer recording film 17 is typically configured to include a reflective film that does not transmit light or a reflective film.

  In FIG. 5D (14), the PC board bonding 2p resin 20 for bonding the L0 layer and the PC board (transparent board) is applied. The PC board bonding 2p resin 20 was dropped in an annular shape on the inner peripheral side of a transparent stamper 19 having a center hole (not shown), and the transparent stamper was rotated to shake off to a uniform thickness. The resin thickness is, for example, 10 to 20 μm, but it is only necessary to have a constant thickness. The PC board bonding 2p resin 20 does not need to consider transferability, and only needs to satisfy releasability and thickness accuracy. As the PC substrate bonding 2p resin, a urethane acrylate-based 2p resin was used. The glass transition point after curing was 35 ° C., and the elastic modulus was 20 MPa at 23 ° C.

  In FIG. 5D (15), the PC board 15 is formed on the transparent stamper 19 on which the 2p resin 18 for the intermediate layer 3, the L0 layer recording film 17 and the 2p resin 20 for bonding are formed using a center hole (not shown). Aligned and overlaid. Thereafter, UV light is irradiated from the UV light source 5 through the PC board 15, and the PC board bonding 2p resin 20 is cured. The PC board 15 has a thickness of 1.1 mm, a diameter of 120 mm, and a center hole diameter of 15 mm. The PC board 15 can use the used transparent stamper 19. Even if optical characteristics such as transmittance are slightly deteriorated by UV irradiation, there is no problem because the light flux for recording / reproduction does not pass through the PC board 15. Thereby, since the used transparent stamper 19 is not discarded, the cost can be reduced.

  In FIG. 5D (16), after the 2p resin 20 for bonding the PC board is cured, the transparent stamper 19 is peeled off, and the information pattern 13 of the L1 layer is formed on the PC board 15. The peeled transparent stamper 19 can be used as a substrate for a multilayer optical recording medium to be manufactured next, as described in FIG. 5D (15).

  In FIG. 5D (17), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer. The L1 layer recording film 14 is a translucent film.

  In FIG. 5E (18), the 2p resin 11 for the intermediate layer 2 for forming the intermediate layer 2 provided on the L1 layer recording film 14 is applied. The 2p resin 11 for the intermediate layer 2 is dropped in an annular shape on the inner peripheral side of the PC board 15 having a center hole (not shown), and is spun off by rotating the PC board to obtain a uniform thickness (fourth constant thickness). It was. The thickness of this resin is 15 μm, for example. As the 2p resin for the intermediate layer 2, a urethane acrylate-based 2p resin was used, the glass transition point after curing was 25 ° C., and the elastic modulus was 1 MPa.

  In FIG. 5E (19), the laminated body after the process shown in FIG. 5B (8) is aligned and overlapped on the 2p resin 11 for the intermediate layer 2 using the center hole (not shown) of the glass substrate 1. The Thereafter, UV light is irradiated from the UV light source 5 through the glass substrate 1, and the 2p resin 11 for the intermediate layer 2 is cured. At this time, the L3 layer recording film 6 and the L2 layer recording film 10 need to be translucent at the wavelength of the UV light beam, and preferably the integrated transmittance is 20% or more. Further, if a visible light source is used instead of a UV light source and a resin that cures at the wavelength of the visible light beam is selected so that the integrated transmittance of the L3 layer recording film 6 and the L2 layer recording film 10 is 50% or more, the resin is cured. Time can be shortened. The 2p resin 11 for the intermediate layer 2 may be applied to the L2 layer recording film 10 and then overlapped with the L1 layer recording film 14 on the PC substrate 15.

  In FIG. 5E (20), after the 2p resin 11 for the intermediate layer 2 is cured, the glass substrate 1 is peeled, and the optical recording medium having a four-layer structure according to the present invention is completed.

  FIG. 5E (20) shows a sectional view of the completed four-layer type optical recording medium of the present embodiment. Four recording layers L0 (17), L1 (14), L2 (10), and L3 (6) from the PC substrate side on the PC substrate 15 are intermediate layers 3 (18) between the L0 layer and the L1 layer, respectively. The intermediate layer 2 (11) is disposed between the L1 layer and the L2 layer, and the intermediate layer 1 (7) is disposed between the L2 layer and the L3 layer. The cover layer 2 covers the L3 layer. A light beam for recording / reproduction enters the medium from the direction of the cover layer 2.

  As described in FIGS. 5A (4), 5B (8), and 5C (13), the recording films 6, 10, and 17 are formed on the information patterns of the L3 layer, the L2 layer, and the L0 layer according to the following procedure. A film is formed. First, on the information patterns 4, 9 and 16 of the L3, L2 and L0 layers formed by guide grooves and pits, a dielectric layer, an interface layer if necessary, a recording layer, an interface layer if necessary, a reflective layer If necessary, high refractive index layers are sequentially formed. That is, a film is formed on the information pattern in the order of dielectric layer-recording layer-reflection layer.

  On the other hand, as described in FIG. 5D (17), the L1 layer recording film 14 is formed on the information pattern 13 of the L1 layer by the following procedure. First, a reflective layer is formed on the information pattern 13 of the L1 layer formed by guide grooves and pits, and an interface layer, a recording layer, and an interface layer and a dielectric layer are sequentially formed as necessary. Is done. That is, the film is formed on the information pattern in the order of the reflective layer, the recording layer, and the dielectric layer in the reverse order of the L3 layer, the L2 layer, and the L0 layer.

  By employing the optical recording medium manufacturing method of the present invention, an inexpensive four-layer optical recording medium can be manufactured by using a metal stamper that can be used repeatedly. In addition, by using a transparent stamper that is difficult to reuse, which is a factor of high cost, as a substrate, an inexpensive optical recording medium having a four-layer structure can be manufactured.

  The glass transition point Tg of the 2p resin for the intermediate layer is [Tg2 of the 2p resin for the intermediate layer 1] ≧ [Tg3 of the 2p resin for the intermediate layer 3]> [Tg1 of the 2p resin for the cover sheet]> [For PC substrate bonding] 2p resin Tg4] ≧ [Tg5 of 2p resin for intermediate layer 2].

  According to the configuration of the present embodiment, the stamper A, the stamper B, and the stamper C can be easily peeled off from the 2p resin for the cover sheet, the 2p resin for the intermediate layer 1, and the 2p resin for the intermediate layer 3 as in the previous embodiment. . Similarly, the transparent stamper and the glass substrate could be easily separated from the 2p resin for the intermediate layer 3 and the 2p resin for the cover sheet, respectively.

  The stamper B8 can be easily peeled from the 2p resin 7 for the intermediate layer 1 by Tg2> Tg1, and the transparent stamper 19 can be easily peeled from the 2p resin 18 for the intermediate layer 3 by Tg3> Tg4. Moreover, the glass substrate 1 was able to peel easily from 2p resin 2 for cover sheets by Tg1> Tg4. Therefore, by satisfying Tg2> Tg1> Tg4 and Tg3> Tg4, the stamper and the substrate can be easily peeled off.

  In the present embodiment, in addition to the relationship related to Tg, it is preferable that Tg4 ≧ Tg5 is satisfied, that is, Tg2> Tg1> Tg4 ≧ Tg5 and Tg3> Tg4 are satisfied. By satisfying this requirement, the intermediate resin layer having a high glass transition point and the low resin layer for the intermediate layer are alternately formed as in this embodiment. As a result, the stress of the resin layer is alleviated, and even if there is a change in temperature and humidity or a drop impact, problems such as deterioration of TILT and peeling of each resin layer do not occur, and an optical recording medium with high long-term reliability can be obtained. can get.

  According to the present invention, it is possible to manufacture an optical recording medium at a low cost by using a metal stamper that can be used repeatedly. In addition, it is possible to supply an inexpensive optical recording medium by diverting a transparent stamper that is difficult to reuse as a substrate, which is a factor of high cost.

  Further, according to the present invention, focusing on the glass transition point and the elastic modulus of the resin, while maintaining the transferability of the information pattern formed on the stamper, both the adhesion to the recording film and the release property of the stamper are compatible. It was possible to improve productivity.

  Furthermore, according to the present invention, it is possible to prevent defects such as deterioration of TILT and peeling of each resin layer due to changes in temperature and humidity, drop impact, and the like, and it is possible to provide an optical recording medium with high long-term reliability.

Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the two-layer type optical recording medium by this invention Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the two-layer type optical recording medium by this invention Sectional drawing for demonstrating the structure of the two-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the two-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the two-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the two-layer type optical recording medium by this invention Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 1st Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating 2nd Embodiment of the manufacturing method of the four-layer type optical recording medium by this invention Process sectional drawing for demonstrating the prior art example of the manufacturing method of a four-layer type optical recording medium Process sectional drawing for demonstrating the prior art example of the manufacturing method of a four-layer type optical recording medium Process sectional drawing for demonstrating the prior art example of the manufacturing method of a four-layer type optical recording medium Process sectional drawing for demonstrating the prior art example of the manufacturing method of a four-layer type optical recording medium

Explanation of symbols

1 glass substrate 2 2p resin for cover sheet 3 stamper A
4 L3 layer pattern 5 UV light source 6 L3 layer recording film 7 2p resin for intermediate layer 1 8 Stamper B
9 L2 layer pattern 10 L2 layer recording film 11 2p resin for intermediate layer 2 12 Stamper C
13 L1 layer pattern 14 L1 layer recording film 15 PC board 16 L0 layer pattern 17 L0 layer recording film 18 2p resin for intermediate layer 3 19 Transparent stamper 19-1 Transparent stamper A
19-2 Transparent Stamper B
19-3 Transparent Stamper C
20 2p resin for PC board adhesion 21 Stamper A for injection molding
22 Stamper B for injection molding
23 Light beam incident direction 24 L0 reflection layer 25 L0 interface layer 26 L0 recording layer 27 L0 interface layer 28 L0 dielectric layer 29 L1 high refractive index layer 30 L1 reflection layer 31 L1 interface layer 32 L1 recording layer 33 L1 interface layer 34 L1 dielectric Body layer

Claims (31)

A method for producing a multilayer optical recording medium having two or more information recording layers provided with a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Forming a first resin layer on which a first pattern is formed on a support substrate;
Forming a first information recording layer on the first pattern forming surface of the first resin layer;
Forming a second information recording layer on the second pattern formation surface on the base substrate;
Bonding the support substrate and the base substrate through a second resin layer with the first pattern formation surface side and the second pattern formation surface side facing each other;
A step of peeling the support substrate;
The first information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium, wherein the glass transition point of the resin of the first resin layer is higher than the glass transition point of the resin of the second resin layer. A method for producing a multilayer optical recording medium having two or more information recording layers provided with a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Forming a first resin layer having a first pattern forming surface and a second pattern forming surface on the lower surface and the upper surface, respectively, on the support substrate;
Forming a first information recording layer on the second pattern formation surface;
The second pattern forming surface side of the support substrate and the base substrate are opposed to each other and bonded together via a second resin layer;
Peeling the support substrate;
Forming a second information recording layer on the first pattern formation surface of the first resin layer;
The second information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium, wherein the glass transition point of the resin of the first resin layer is higher than the glass transition point of the resin of the second resin layer. Forming a resin protective layer on the second information recording layer formed on the second pattern formation surface;
The multilayer optical recording medium according to claim 2, wherein the glass transition point of the resin of the first resin layer is higher than the glass transition temperature of the resin of the second resin layer and the glass transition point of the resin of the resin protective layer. Production method. A method for producing a multilayer optical recording medium having two or more information recording layers provided with a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Applying a first photoreactive curable resin on the transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern forming surface;
Transferring and forming a second pattern from the second stamper on the base substrate;
Forming a second information recording layer on the second pattern forming surface of the base substrate;
Applying a second photoreactive curable resin to the pattern forming surface side of either the first pattern or the second pattern;
The transparent support substrate and the base substrate are overlapped with each other through the second photoreactive curable resin so that the first pattern formation surface side and the second pattern formation surface side face each other, and light is transmitted from the transparent support substrate direction. Irradiating and curing and bonding the second photoreactive curable resin;
Having the step of peeling the transparent support substrate,
The first information recording layer is a translucent layer that transmits the recording light beam,
A method for producing a multilayer optical recording medium, wherein the glass transition point of the first photoreactive curable resin is higher than the glass transition point of the second photoreactive curable resin.   The multilayer optical recording medium according to claim 4, wherein a thickness of the layer made of the first photoreactive curable resin applied on the transparent support substrate is thicker than a thickness of the layer made of the second photoreactive curable resin. Manufacturing method.   The method for producing a multilayer optical recording medium according to claim 4, wherein the transparent support substrate is made of a transparent material that is not deteriorated by the irradiation light.   The method of manufacturing a multilayer optical recording medium according to claim 4, wherein the step of transferring and forming the second pattern from the second stamper on the base substrate is performed by injection molding.   5. The method of manufacturing a multilayer optical recording medium according to claim 4, wherein the first stamper and the second stamper are made of metal. A method for producing a multilayer optical recording medium having two or more information recording layers provided with a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Applying a first photoreactive curable resin on the transparent support substrate on which the first pattern is formed;
The first photoreactive curable resin is applied to the transparent support substrate on which the first pattern is formed and the stamper on which the second pattern is formed so that the first pattern formation surface and the second pattern formation surface are opposed to each other. The first photoreactive curable resin is cured by irradiating light from the transparent support substrate direction, and transferring the first and second patterns;
Peeling the stamper;
Forming a first information recording layer on the second pattern forming surface of the first photoreactive curable resin;
A step of facing the second pattern forming surface and the base transparent substrate, and bonding the transparent support substrate and the base transparent substrate through a second photoreactive curable resin;
Peeling the transparent support substrate;
Forming a second information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a third photoreactive curable resin to the first pattern forming surface on which the second information recording layer is formed;
Irradiating and curing the third photoreactive curable resin on the first pattern forming surface to form a resin protective layer made of the cured third photoreactive curable resin;
The second information recording layer is a translucent layer that transmits the recording light beam,
Method for producing multilayer optical recording medium, wherein glass transition point of first photoreactive curable resin is higher than glass transition point of second photoreactive curable resin and glass transition point of third photoreactive curable resin . The step of bonding the transparent support substrate and the base transparent substrate,
Applying a second photoreactive curable resin to either the second pattern forming surface side or the base transparent substrate side;
The second pattern formation surface side and the base transparent substrate are opposed to each other, the transparent support substrate and the base transparent substrate are overlapped via a second photoreactive curable resin, and light is irradiated from the direction of the base transparent substrate. The method for producing a multilayer optical recording medium according to claim 9, comprising the step of curing the photoreactive curable resin.   The multilayer optical recording medium according to claim 9, wherein the thickness of the layer made of the third photoreactive curable resin is thicker than the thickness of the layer made of the first photoreactive curable resin applied on the transparent support substrate. Manufacturing method.   The method for producing a multilayer optical recording medium according to claim 9, wherein the first pattern of the transparent support substrate is formed by injection molding.   The method for producing a multilayer optical recording medium according to claim 9, wherein the used transparent support substrate that has been irradiated with light in a previously produced production process is reused as the base substrate.   The method for manufacturing a multilayer optical recording medium according to claim 9, wherein the stamper is made of metal. A method for producing a multilayer optical recording medium having four or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Applying a first photoreactive curable resin on the transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a second photoreactive curable resin on the first pattern forming surface on which the first information recording layer is formed;
Transferring the second pattern from the second stamper onto the second photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the second photoreactive curable resin;
Forming a second information recording layer on the second pattern formation surface of the second photoreactive curable resin;
Applying a third photoreactive curable resin on the second pattern forming surface on which the second information recording layer is formed;
Transferring the third pattern from the third stamper onto the third photoreactive curable resin and irradiating light from the transparent support substrate direction to cure the third photoreactive curable resin;
Forming a third information recording layer on the third pattern formation surface of the third photoreactive curable resin;
Transferring and forming a fourth pattern from the fourth stamper on the base substrate;
Forming a fourth information recording layer on a fourth pattern formation surface of the base substrate;
Applying a fourth photoreactive curable resin to the pattern forming surface side of either the third pattern or the fourth pattern;
3rd pattern formation surface side and 4th pattern formation surface side are made to oppose, the said transparent support substrate and the said base substrate are piled up via 4th photoreactive hardening resin, and light is irradiated from a transparent support substrate direction And curing and bonding the fourth photoreactive curable resin;
Having the step of peeling the transparent support substrate,
The first, second and third information recording layers are translucent layers that transmit the recording light beam,
The glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, the glass transition point of the third photoreactive curable resin is Tg3, and the fourth photoreaction. When the glass transition point of the thermosetting resin is Tg4, the following relationship:
Tg3 ≧ Tg2>Tg1> Tg4
The manufacturing method of the multilayer optical recording medium which satisfy | fills.   The thickness of the first photoreactive curable resin is the thickness of the second photoreactive curable resin, the third constant thickness of the third photoreactive curable resin, and the thickness of the fourth photoreactive curable resin. The method for producing a multilayer optical recording medium according to claim 15, wherein the method is thicker.   The method for producing a multilayer optical recording medium according to claim 15, wherein the transparent support substrate is made of a transparent material that is not deteriorated by the irradiation light.   The method for manufacturing a multilayer optical recording medium according to claim 15, wherein the fourth pattern of the base substrate is formed by injection molding.   16. The method for manufacturing a multilayer optical recording medium according to claim 15, wherein the first, second, third and fourth stampers are made of metal. A method for producing a multilayer optical recording medium having four or more information recording layers having a pattern comprising pits or guide grooves constituting a plurality of information recording tracks,
Applying a first photoreactive curable resin on the first transparent support substrate;
Transferring the first pattern from the first stamper onto the first photoreactive curable resin and irradiating light from the first transparent support substrate direction to cure the first photoreactive curable resin;
Forming a first information recording layer on the first pattern formation surface of the first photoreactive curable resin;
Applying a second photoreactive curable resin on the first pattern forming surface on which the first information recording layer is formed;
Transferring the second pattern from the second stamper onto the second photoreactive curable resin and irradiating light from the first transparent support substrate direction to cure the second photoreactive curable resin;
Forming a second information recording layer on the second pattern formation surface of the second photoreactive curable resin;
Applying a third photoreactive curable resin on the second transparent support substrate on which the third pattern is formed or on the third stamper on which the fourth pattern is formed;
The second transparent support substrate and the third stamper are overlapped with each other through the third photoreactive curable resin with the third pattern formation surface side and the fourth pattern formation surface side facing each other, and the second transparent The third photoreactive curable resin is cured by irradiating light from the support substrate direction, and the third pattern and the fourth pattern are formed on the lower surface of the cured third photoreactive curable resin layer. A transfer process;
Peeling the third stamper;
Forming a third information recording layer on the fourth pattern formation surface;
The 4th pattern formation surface in which the 3rd information recording layer was formed, and the 3rd transparent support substrate are made to oppose, and the 2nd transparent support substrate and the 3rd transparent support are interposed via the 4th photoreactive hardening resin. A step of bonding the substrate,
Peeling the second transparent support substrate;
Forming a fourth information recording layer on the third pattern formation surface of the third photoreactive curable resin;
Applying a fifth photoreactive curable resin to the pattern forming surface of either the second pattern or the third pattern;
The first transparent support substrate and the third transparent support substrate are overlapped with each other through the fifth photoreactive curable resin with the second pattern formation surface side and the third pattern formation surface side facing each other. Irradiating light from the substrate direction to cure and bond the fifth photoreactive curable resin;
Having a step of peeling the first transparent support substrate;
The first, second and fourth information recording layers are translucent layers that transmit the recording light beam,
The glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, the glass transition point of the third photoreactive curable resin is Tg3, and the fourth photoreaction. When the glass transition point of the thermosetting resin is Tg4, the following relationship:
Tg2>Tg1> Tg4 and Tg3> Tg4
The manufacturing method of the multilayer optical recording medium which satisfy | fills. The glass transition point of the first photoreactive curable resin is Tg1, the glass transition point of the second photoreactive curable resin is Tg2, the glass transition point of the third photoreactive curable resin is Tg3, and the fourth photoreaction. When the glass transition point of the photocurable curable resin is Tg4 and the glass transition point of the fifth photoreactive curable resin is Tg5, the following relationship:
Tg2>Tg1> Tg4 ≧ Tg5 and Tg3> Tg4
The method for producing a multilayer optical recording medium according to claim 20, wherein The step of causing the fourth pattern forming surface on which the third information recording layer is formed and the third transparent support substrate to face each other, and bonding the second transparent support substrate and the third transparent support substrate together,
Applying a fourth photoreactive curable resin to either the fourth pattern forming surface side or the third transparent support substrate;
The fourth pattern formation surface side and the third transparent support substrate are opposed to each other, and the second transparent support substrate and the third transparent support substrate are overlapped with each other via the fourth photoreactive curable resin, The method for producing a multilayer optical recording medium according to claim 20 or 21, comprising a step of irradiating light from the transparent substrate direction to cure and bond the fourth photoreactive curable resin.   The thickness of the first photoreactive curable resin is greater than the thickness of the second photoreactive curable resin, the thickness of the third photocurable curable resin, and the thickness of the fifth photoreactive curable resin. The method for producing a multilayer optical recording medium according to claim 20 or 21.   The method for producing a multilayer optical recording medium according to claim 20 or 21, wherein the first transparent support substrate is made of a transparent material that is not deteriorated by the irradiation light.   The method for producing a multilayer optical recording medium according to claim 20 or 21, wherein the third pattern of the second transparent support substrate is formed by injection molding.   The method for producing a multilayer optical recording medium according to claim 20 or 21, wherein the used second transparent support substrate irradiated with light in the previously produced production process is reused as the third transparent support substrate.   The method of manufacturing a multilayer optical recording medium according to claim 20 or 21, wherein the first, second and third stampers are made of metal.   The glass transition point of the resin of the first resin layer is in the range of 70 ° C to 200 ° C, and the glass transition point of the resin of the second resin layer is in the range of 25 ° C to 150 ° C. A method for producing a multilayer optical recording medium according to any one of the above.   The glass transition point of the resin of the first resin layer is in the range of 70 ° C. to 200 ° C., and the glass transition point of the resin of the second resin layer and the glass transition point of the resin of the resin protective layer are 25 ° C. to 150 ° C. The method for producing a multilayer optical recording medium according to claim 3, which is in the range.   The glass transition point of the first, second and third photoreactive curable resins is in the range of 70 ° C. to 200 ° C., and the glass transition point of the fourth photoreactive curable resin is in the range of 25 ° C. to 150 ° C. The method for producing a multilayer optical recording medium according to any one of claims 15 to 19. The glass transition points of the first, second and third photoreactive curable resins are in the range of 70 ° C. to 200 ° C., and the glass transition points of the fourth and fifth photoreactive curable resins are from 25 ° C. to 150 ° C. The method for producing a multilayer optical recording medium according to any one of claims 20 to 27, which is in the range of

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