JP2007012224A - Optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer type optical information recording medium having thin disk thickness, nearly free from generation of cross-talk and nearly free from incorrect reading when reproduction is performed. <P>SOLUTION: An optical information recording substrate (21) has ruggedness on its surface and a reflection layer (23a) formed on the surface of the ruggedness. An intermediate resin layer (11a) has ruggedness on the reflection layer and a reflection layer (23b) formed on the surface of the ruggedness. In the optical information recording medium wherein the intermediate resin layer (11a) is provided on the reflection layer (23a) of the optical information recording substrate (21) so that the surface of the intermediate resin layer having no ruggedness is opposed to the reflection layer (23a) of the surface of the substrate (21) along the ruggedness on the reflection layer of the surface of substrate, and one or more other intermediate layers each having ruggedness and a reflection layer are further provided on the reflection layer of the intermediate resin layer already provided along the ruggedness, at least adjacent two layers of the intermediate resin layers have refractive indices different from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical information recording medium on which information such as large-capacity characters, audio, moving images, etc. such as DVD (Digital Versatile Disc) and CD (Compact Disc) is recorded and / or recordable as a digital signal. The present invention relates to a type optical information recording medium, a method for producing the same, and a photocurable transfer sheet used for the production.

  Audio CDs and CD-ROMs are widely used as recorded optical information recording media with pits formed on the surface as digital signals. Recently, DVDs with pit recording on both sides capable of recording moving images and recordings have been made. As a next-generation recording medium for CD, it has been gradually used. In addition, CD-R, CD-RW, DVD-R, DVD-RW and the like that can be recorded by a user in which pits and grooves are formed have been used.

  Furthermore, as a next-generation DVD, a proposal for a next-generation optical disc unified standard “Blu-ray Disc” has already been made on February 10, 2002. The main specifications are recording capacity: 23.3 / 25/27 GB, laser wavelength: 405 nm (blue-violet laser), lens numerical aperture (N / A): 0.85, disc diameter: 120 mm, disc thickness: 1.2 mm Track pitch: 0.32 μm or the like.

  As described above, the blu-ray disc has a narrow groove and a small pit. For this reason, it is necessary to narrow down the spot of the reading laser. However, if the spot is made smaller, it will be greatly affected by the tilt of the disc, and even if the DVD to be reproduced is slightly bent, it cannot be reproduced. In order to compensate for this disadvantage, it is considered to reduce the thickness of the substrate and to make the thickness of the cover layer on the pit on the laser irradiation side about 0.1 mm.

  Development of practical application of a multilayer optical recording medium in which two or more recording surfaces on which pits are formed so as to satisfy the above-described requirements has been promoted is in progress.

  FIG. 7 shows a schematic cross-sectional view of an example of an optical disc for a Blu-ray disc. A schematic sectional view of an optical information recording medium having a two-layer structure in which a first recording surface 2 and a second recording surface 3 are laminated on a transparent substrate 1 via an intermediate intermediate resin layer (intermediate layer) 4 is shown. Yes. Each of the recording surfaces 2 and 3 has, for example, a pit in which data information is recorded, fine concavo-convex such as an address and a tracking pre-groove for recording on a disc on which information is recorded. Even if they are equal to each other, fine irregularities such as pregrooves are formed.

  The first recording surface 2 is formed as fine irregularities on the transparent substrate 1 formed to a relatively thick thickness of, for example, 1.2 mm. The transparent substrate 1 on which the fine irregularities are formed is formed by injection molding using a transparent resin such as polycarbonate, for example, and this is coated with a reflective layer 5 of a semi-transparent film made of Ag alloy, for example.

  The second recording surface 3 is formed by a so-called 2P method (Photopolymerization method). That is, a photocurable resin is applied onto the first recording surface 2, and a stamper on which the fine unevenness that forms the second fine unevenness constituting the second recording surface 3 is transferred is pressed onto the transparent substrate 1. It forms by irradiating light to a photocurable resin from the side and hardening this (formation of the cured layer 4 of photocurable resin). Then, a reflective film 6 made of an Al vapor deposition film or the like is formed on the second fine unevenness to form the second recording surface 3. Then, a protective film 7 made of a photocurable resin or the like is formed on the second recording surface 3.

  Then, the first recording surface 2 and the second recording surface 3 are each irradiated with the laser beam 8 to read the signal due to the unevenness.

  Furthermore, Non-Patent Document 1 (OPTRONICS (2004) No. 12, pp. 73-77) introduced a four-layer disc as a high-capacity disc of a blu-ray disc, and instead of the coating type photocurable resin. It has been proposed to use a photopolymer sheet. In a Blu-ray disc, since the NA of the objective lens is large, an intermediate layer (the hardened layer 4 of the photo-curing resin (between the first recording surface 2 and the second recording surface 3) is formed between the cover layer and the recording surface. Is required to have a high level of thickness accuracy. Here, by using a photopolymer sheet, the intermediate layer forming the recording surface can be made thin and the thickness accuracy can be several μm or less. Further, in a multi-layer such as four layers, when the thickness of the intermediate layer is reduced, deterioration of jitter due to leakage of signals (correlated crosstalk) on adjacent recording surfaces is likely to occur. For example, the laser beam condensed on the pits on the first recording surface may be reflected on the second recording surface and may also be collected on the back side of the reflective layer on the third recording surface. The laser light focused on the pit overlaps to cause optical interference. In order to solve this, the thicknesses of the adjacent intermediate layers are made different from each other.

OPTRONICS (2004) No. 12, pages 73-77

  In the case of a multilayer (multiple recording) optical disc (DVD), the laser beam condensed during reproduction is reflected not only on the recording surface to be read but also on other recording surfaces as described above, and thus is irrelevant to the read signal. Since reflected light also enters, signal reading errors are likely to occur. As described above, it can be improved by changing the thickness of the intermediate layer between the recording surfaces, but in the case of multiple layers, the thickness of each intermediate layer is further increased in order to reduce the overall thickness of the disc. It needs to be small. However, there is a limit to the reduction in the thickness of the intermediate layer, which is not yet sufficient. Further, when the thickness of the intermediate layer is reduced in this way, the occurrence of the correlated crosstalk is likely to occur, and therefore, it may not be possible to sufficiently cope with the change of the thickness of the intermediate layer alone.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical information recording medium having a thin disk and almost no reading error at the time of reproduction despite a high capacity.

  In addition, the present invention provides an optical information recording medium, particularly a multilayer optical information recording medium, which has a thin disk, hardly generates crosstalk, and has almost no reading error during reproduction despite its high capacity. The purpose is to do.

  Another object of the present invention is to provide a method for producing the optical information recording medium.

  A further object of the present invention is to provide a photocurable transfer sheet useful for the production of the optical information recording medium.

The above purpose is
On the surface of the optical information recording substrate having irregularities as recording pits and / or grooves and further having a reflective layer formed on the irregular surface, irregularities as recording pits and / or grooves are formed on the surface. An intermediate resin layer having a reflective layer formed on the uneven surface, the surface of the intermediate resin layer having no unevenness facing the reflective layer on the substrate surface, One or more other intermediate resin layers that are provided along the unevenness and further have an uneven surface and a reflective layer are arranged so that the surface without the unevenness of the intermediate resin layer faces the reflective layer of the already provided intermediate resin layer. An optical information recording medium provided on the reflective layer of the intermediate resin layer already provided along the unevenness thereof,
This is achieved by an optical information recording medium characterized by an optical information recording medium characterized in that at least two adjacent layers of the intermediate resin layer have different refractive indexes.

Preferred embodiments of the optical information recording medium of the present invention are listed below.
(1) The intermediate resin layer is a cured layer of a photocurable composition containing a polymer and a reactive diluent having a photopolymerizable functional group.
(2) The polymer of the at least one intermediate resin layer is a polymer having a fluorine atom in the molecular structure. A low refractive index can be advantageously obtained by using such a polymer.
(3) The polymer having a fluorine atom is an acrylic resin. The refractive index can be easily adjusted, and the transferability of pits and the like is excellent.
(4) The acrylic resin is a polymer or copolymer of a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom. The refractive index can be lowered and the transferability of pits and the like is excellent.
(5) The acrylic resin is a copolymer of (meth) acrylate having a fluorine atom and (meth) acrylate having a hydroxyl group. The refractive index can be lowered, and control of transferability of pits, maintenance of pit shape, etc. is easy.
(6) The reactive diluent having a photopolymerizable functional group contains (meth) acrylate having a fluorine atom. The refractive index can be lowered and the transferability of pits and the like can be easily controlled.
(7) The photocurable composition further contains polyisocyanate (preferably diisocyanate). Post-crosslinking is possible, and the shape retention of the film before transfer is improved.
(8) A photocurable composition contains 0.1-10 mass% of photoinitiators.
(9) The light transmittance in the wavelength region of 380 to 420 nm of the intermediate resin layer is 70% or more.
(10) The light transmittance in the wavelength region of 380 to 800 nm of the intermediate resin layer is 70% or more.
(11) The thickness of the intermediate resin layer is 5 to 30 μm.
(12) The refractive index of the intermediate resin layer closest to the transparent substrate is 1.42 or less.
(13) The difference in refractive index between adjacent intermediate resin layers is 0.02 or more (particularly 0.02 to 0.10). This is advantageous for reducing crosstalk and reducing jitter.
(14) A protective layer is provided on the reflective layer of the uppermost intermediate resin layer.

The optical information recording medium of the present invention has the following production method:
That is,
The following steps (2) to (4):
(2) It has a photocurable transfer layer made of a photocurable composition that can be deformed by pressurization, and a release sheet is provided on one or both surfaces of the photocurable transfer layer. A step of removing one release sheet of the photocurable transfer sheet when the release sheet is provided on both sides thereof;
(3) Photocuring of the photocurable transfer sheet on the reflective layer of the substrate having irregularities as recording pits and / or grooves on the surface and further provided with a reflective layer along the irregularities on the irregular surface. A laminate in which the surface of the light-sensitive transfer layer is placed in contact with the uneven surface of the reflective layer, and the surface of the photocurable transfer sheet is adhered along the uneven surface of the reflective layer by pressing them. A step of forming; and (4) a step of removing the other release sheet from the laminate,
(5) The irregular surface of the stamper having irregularities as recording pits and / or grooves is placed on the surface of the photocurable transfer layer from which the release sheet of the laminate has been removed, and these are pressed to press the light. Forming a laminate in which the surface of the curable transfer sheet is adhered along the uneven surface;
(6) A step of providing irregularities on the surface of the photocurable transfer layer by curing the photocurable transfer layer of the laminate having the stamper by ultraviolet irradiation and then removing the stamper;
(7) providing a reflective layer on the uneven surface of the photocurable transfer layer;
(8) The surface of the photocurable transfer layer of the photocurable transfer sheet having a photocurable transfer layer having a refractive index different from the refractive index of the already cured photocurable transfer layer on the reflective layer is Placing the surface so as to be in contact with the uneven surface of the reflective layer and pressing them to form a laminate in which the surface of the photocurable transfer sheet is adhered along the uneven surface of the reflective layer;
(9) removing the other release sheet from the laminate;
(10) The irregular surface of the stamper having irregularities as recording pits and / or grooves is placed on the surface of the photocurable transfer layer from which the release sheet of the laminate has been removed, and these are pressed to press the light. Forming a laminate in which the surface of the curable transfer sheet is adhered along the uneven surface;
(11) A step of providing irregularities on the surface of the photocurable transfer layer by curing the photocurable transfer layer of the laminate having the stamper by ultraviolet irradiation and then removing the stamper;
(12) A step of providing a reflective layer on the uneven surface of the photocurable transfer layer;
And the method (8) to (12) are performed at least once, and can be advantageously obtained by a method of manufacturing an optical information recording medium.

In the manufacturing method, before the step (2),
(1) A step of punching a photocurable transfer sheet into a disc shape; or (1) A step of punching out the photocurable transfer layer of the photocurable transfer sheet and one release sheet into a disc shape, and leaving the other release sheet as it is. ;
It is preferable to carry out.

  The photocurable composition corresponds to the composition in the optical information recording medium described above.

  A preferred embodiment of the optical information recording medium of the present invention can also be applied to the manufacturing method.

Furthermore, the present invention provides
A photocurable transfer sheet having a photocurable transfer layer made of a photocurable composition that can be deformed by pressurization,
There is also a photocurable transfer sheet, wherein the photocurable composition contains a polymer having a fluorine atom in a molecular structure and a reactive diluent having a photopolymerizable functional group.

  The photocurable transfer sheet of the present invention can be advantageously used for forming a low refractive index layer in the production of the optical information recording medium of the present invention (particularly the production method described above).

Preferred embodiments of the photocurable transfer sheet of the present invention are listed below.
(1) The polymer having a fluorine atom is an acrylic resin.
(2) The acrylic resin is a polymer or copolymer of a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom.
(3) The acrylic resin is a copolymer of (meth) acrylate having a fluorine atom and (meth) acrylate having a hydroxyl group.
(4) The reactive diluent having a photopolymerizable functional group contains (meth) acrylate having a fluorine atom.
(5) The photocurable composition further contains a diisocyanate.
(6) A photocurable composition contains 0.1-10 mass% of photoinitiators.
(7) The refractive index of the photocurable transfer layer is 1.42 or less.

  The optical information recording medium of the present invention is a multilayer type (multiple recording type) optical information recording medium having three or more intermediate resin layers (intermediate layers) on which uneven recording surfaces such as recording pits are formed. In the optical information recording medium of the present invention, the intermediate resin layers adjacent to these intermediate resin layers are formed to have different refractive indexes. For this reason, even though the thickness of the intermediate resin layer is small, there is almost no occurrence of crosstalk, so the jitter is small, and thus there is almost no signal reading error due to laser light. In particular, by making the first intermediate resin layer on the transparent substrate side a layer having a low refractive index of 1.42 or less, a multilayer optical information recording medium with few reading errors can be easily obtained.

  In addition, by using a photocurable transfer sheet containing a polymer having a fluorine atom in the molecular structure of the present invention, among the intermediate resin layers of the optical information recording medium of the present invention, a layer having a low refractive index can be easily designed and formed. Therefore, the multilayer optical information recording medium of the present invention can be produced advantageously.

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

  FIG. 1 shows a schematic sectional view of an example of an embodiment of the optical information recording medium of the present invention.

  As shown in FIG. 1, for example, the optical information recording medium of the present invention includes a substrate 21 having an uneven surface, a reflective layer 23a provided on the uneven surface, and an intermediate resin layer provided on the uneven surface of the reflective layer 23a. 11a, a reflective layer (generally a reflective layer having a lower reflectance than the previous reflective layer 23a) 23b provided on the concave and convex upper surface, and a refractive index different from that of the intermediate resin layer 11a provided on the concave and convex surface of the reflective layer 23b. Value of the intermediate resin layer 11b, the reflective layer 23c formed on the uneven surface thereof (reflective layer having a lower reflectance than the previous reflective layer 23b), and the refractive index of the intermediate resin layer 11b provided on the uneven surface of the reflective layer 23c The intermediate resin layer 11c having different refractive index values and the reflective layer 23d (a reflective layer having a lower reflectance than the previous reflective layer 23c) formed on the uneven surface thereof are configured. On the reflective layer 23d, an organic polymer film (cover layer) 46 and the like are attached as described above. As shown in FIG. 1, the recording surface (on the substrate and the intermediate resin layer) of the concavo-convex surface is generally four layers, but may be three layers, and may be five layers or more. The correlation between the magnitudes of the reflectances in the four reflective layers may be opposite to the above.

  In the present invention, among the intermediate resin layers 11a, 11b, and 11c, the refractive indexes of at least two adjacent layers are different from each other. Crosstalk is reduced and jitter is reduced. Note that the refractive index of the intermediate resin layer 11a is different from that of the transparent substrate, but is generally lower than the refractive index of the transparent substrate.

  In the present invention, it is preferable that the refractive index of the intermediate resin layer having a low refractive index out of the intermediate resin layer is 1.42 or less. The difference in refractive index between adjacent intermediate resin layers is 0.02 or more (particularly 0.02 to 0.10). This is particularly advantageous because it reduces crosstalk and reduces jitter.

  The intermediate resin layers 11a, 11b, and 11c are a cured layer (usually a photocured layer) of a photocurable transfer layer generally made of a photocurable composition. The photo-curable transfer layer for forming the intermediate resin layer is a layer that is easily deformed by pressurization so that it can be accurately transferred by pressing the uneven surface of the stamper. In the present invention, photocurable transfer layers having different refractive indexes are generally used.

  The photocurable composition constituting the photocurable transfer layer generally contains a reactive diluent having a polymer and a photopolymerizable functional group as main components. The polymer constituting at least one intermediate resin layer is a polymer having a fluorine atom in the molecular structure. A low refractive index can be advantageously obtained by using such a polymer.

  The polymer having a fluorine atom is an acrylic resin, and is particularly preferably a polymer or copolymer of a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom. Thereby, it is possible to easily obtain a multilayer optical information recording medium having a low refractive index and few reading errors.

  The optical information recording medium of the present invention is a multilayer type (multiple recording type) optical information recording medium having three or more intermediate resin layers (intermediate layers) on which uneven recording surfaces such as recording pits are formed. In the optical information recording medium of the present invention, the intermediate resin layers adjacent to these intermediate resin layers are formed to have different refractive indexes. For this reason, even though the thickness of the intermediate resin layer is small, there is almost no occurrence of crosstalk, so the jitter is small, and thus there is almost no signal reading error due to laser light. In particular, by making the first intermediate resin layer on the transparent substrate side a layer having a low refractive index of 1.42 or less, a multilayer optical information recording medium with few reading errors can be easily obtained.

  In addition, by using a photocurable transfer sheet containing a polymer having a fluorine atom in the molecular structure of the present invention, among the intermediate resin layers of the optical information recording medium of the present invention, a layer having a low refractive index can be easily designed and formed. Therefore, the multilayer optical information recording medium of the present invention can be produced advantageously.

  The polymer constituting the photocurable composition has a polymerizable functional group, which can react with the reactive diluent and is advantageous for speeding up the curing. In addition, by including a diisocyanate in the transfer layer 11 by having a hydroxyl group, it is possible to slightly crosslink the polymer, and in particular, a layer in which the transfer layer oozes out and the layer thickness fluctuation is greatly suppressed can be obtained. It is advantageous. Diisocyanates are effective to some extent even in polymers without hydroxyl groups.

  The photocurable transfer sheet and the intermediate resin layer preferably have a light transmittance of 70% or more in a wavelength region of 380 to 420 nm so that the information can be read with a reproducing laser in order to increase the density of information. In particular, the light transmittance in the wavelength region of 380 to 420 nm is preferably 80% or more. Therefore, the optical information recording medium of the present invention produced using this transfer sheet can be advantageously used in a method of reproducing a pit signal using a laser having a wavelength of 380 to 420 nm.

  The optical information recording medium of the present invention can be produced using the above-mentioned photocurable transfer sheet, for example, as shown in FIGS.

  First, a photocurable transfer sheet 10 shown in FIG. 2 is prepared (1). The photocurable transfer layer 11 has release sheets 12a and 12b on both sides. The release sheet may be either one or not. It is set as appropriate according to the usage.

  The photocurable transfer sheet 10 is first punched into a disk shape. At this time, when the photocurable transfer layer 11 and all of the release sheets 12a and 12b on both sides are punched out (generally in the case of full edge), the photocurable transfer layer 11 and one release sheet 12b are punched into a disk shape, and the other There is a case where the release sheet 12a is left as it is (generally a dry edge), which is appropriately selected (1). As described above, the punching operation in advance can be performed with good workability without using the photocurable transfer sheet of the present invention without causing the transfer layer to ooze out or protrude.

Next, as shown in FIG. 3, the release sheet 12a is removed from the photocurable transfer sheet 10, and a photocurable transfer sheet with the release sheet 12b is prepared (2). The side having no release sheet is opposed to the high-reflectance reflective layer 23a (generally a reflective layer of Al or a thick reflective layer such as AgX) of the concavo-convex surface of the substrate 21 having irregularities as recording pits on the surface. Then, the photocurable transfer sheet 10 is pressed (3). As a result, a laminate (11, 23a, 21) in which the surface of the photocurable transfer sheet is closely adhered along the uneven surface is formed.
Next, a stamper 24 having irregularities as recording pits on the surface is pressed against the surface of the uncured photocurable transfer layer 11 (the surface not in contact with the substrate) by removing the release sheet 12b from the laminate. (5). A laminate (21, 23a, 11, 24) in which the surface of the photocurable transfer layer 11 is in close contact with the uneven surface of the stamper 24 is formed, and the photocurable transfer sheet of the laminate is irradiated with ultraviolet rays (generally, (6) After curing (300 mJ / cm ² or more), the stamper 24 is removed to provide irregularities such as recording pits on the surface of the cured sheet. Thus, a laminate (optical information recording medium) including the substrate 11, the reflective layer 23a, and the intermediate resin layer 11a which is a cured photocurable transfer sheet is obtained. Usually, a reflective layer (generally a reflective layer such as AgX) 23b having a lower reflectance than the reflective layer 23a is provided on the unevenness (the surface of the intermediate resin layer 11a) (7).

Further, by repeating the steps (2) to (7), that is, by forming the intermediate resin layer 11b having a refractive index different from that of the intermediate resin layer 11a and the reflective layer 23c having a lower reflectivity than the reflective layer 23b, FIG. 4 (8), the three-layer optical information recording medium of the present invention having three recording surfaces can be obtained, and the intermediate resin layer 11c and the reflective layer 23c having a refractive index different from those of the intermediate resin layer 11b are lower in reflection. By forming the reflective layer 23d having a refractive index, the four-layer optical information recording medium of the present invention having four recording surfaces as shown in FIG. 4 (9) can be obtained.

  For example, in order to form an optical information recording medium having a four-layer structure, it is manufactured as follows. As shown in FIG. 3, the substrate 21 having irregularities on the surface, the reflective layer 43a and the intermediate resin layer 11a of the cured photocurable transfer sheet obtained in the step (7) and the irregularities (the surface of the cured sheet) A photo-curing transfer layer having a refractive index different from that of the intermediate resin layer 11a on the reflective layer 23b of the laminate formed of the reflective layer (generally a reflective layer having a lower reflectance than the previous reflective layer 23a) 23b. The photocurable transfer sheet 10 is pressed, the stamper is pressed and cured on the surface, the stamper is removed to form the intermediate resin layer 11b having irregularities on the surface, and then the reflective layer 23c (reflectivity from the previous reflective layer 23b is increased). And a photocurable transfer sheet 10 having a photocurable transfer layer having a refractive index different from that of the intermediate resin layer 11b is pressed and cured, and the stamper is removed to form irregularities on the surface. Have The intermediate resin layer 11c is cured, and a light-cured reflective layer 23d (a reflective layer having a lower reflectance than the previous reflective layer 23c) is formed to obtain an optical information recording medium having a four-layer recording surface. Can do. In general, an organic polymer film (cover layer) 26 or the like is attached onto the reflective layer 23d as described above. Thus, the four-layer optical information recording medium shown in FIG. 1 can be obtained.

On the reflective layer on the surface of the cured sheet having recording pits, a photocurable transfer sheet is pressed instead of the organic polymer film (cover layer) 26 and cured by ultraviolet irradiation (generally 300 mJ / cm ² or more). Also good. Alternatively, an ultraviolet curable resin may be applied and cured on the reflective layer on the surface of the cured sheet. The translucent reflective layer may be a normal reflective layer such as Al (for double-sided readout). The stamper may be a substrate having irregularities.

  In the present invention, at least the photocurable transfer layer 11 for producing a multilayer optical information recording medium including the four-layer optical information recording medium shown in FIG. 1 and the intermediate resin layers 11a, 11b, and 11c that are the cured layers are used. Since the refractive indexes of the two adjacent layers (11a and 11b, 11b and 11c) are set to be different from each other, the occurrence of crosstalk is reduced or eliminated, so that the jitter can be kept low, and the laser beam It is possible to eliminate almost all signal (pit) reading errors. The refractive indexes of the plurality of intermediate resin layers are preferably different from each other by at least 0.02 or more (particularly 0.02 to 0.10). This is advantageous because crosstalk is reduced and jitter is reduced. Furthermore, the refractive index of the intermediate resin layer can be set randomly regardless of the stacking order from the substrate side.

  In the above method shown in FIGS. 2 to 4, the reproduction-only optical information recording medium has been described. However, the recording can be performed in the same manner. In the case of a recordable medium, the recording medium generally has grooves or grooves and pits. In this case, instead of the reflective layer and the semitransparent reflective layer, a metal recording layer (in the case of a dye recording layer or when the reflectance of the metal recording layer is low) , Recording layer and reflective layer) are generally provided. Otherwise, the optical information recording medium can be manufactured in the same manner as described above.

  In the present invention, the concavo-convex shape which is a recording pit and / or a groove is pressed against the photocurable transfer layer 11 and the substrate 21 at a relatively low temperature (preferably normal temperature) of 100 ° C. or less (preferably under reduced pressure). The photo-curable transfer sheet is designed so that it can be transferred more accurately. The superposition of the substrates 21 and 51 and the photocurable transfer layer 11 is generally performed with a pressure roll or a simple press (preferably under reduced pressure). Further, the cured layer of the photocurable transfer layer 11 has a good adhesive force with the metal used for the reflective layer on the surface of the substrate 21 and does not peel off. If necessary, an adhesion promoting layer may be provided on the reflective layer.

  In the present invention, the concave and convex shapes that are recording pits and / or grooves are accurately determined by pressing the photocurable transfer layer 11 and the stamper 24 at a low temperature (preferably normal temperature) of 100 ° C. or less (preferably under reduced pressure). A photo-curable transfer sheet is designed to be transferred to the sheet. The stacking of the stamper 24 and the photocurable transfer sheet 11 is generally performed by a pressure roll or a simple press (preferably under reduced pressure). Further, the cured layer of the photocurable transfer layer 11 is generally a layer having a Tg of 65 ° C. or higher (particularly 80 ° C. or higher), and has a very weak adhesive force with a metal such as nickel used for a stamper. The photosensitive transfer sheet can be easily peeled from the stamper.

  Since the substrate 21 is generally a thick plate (usually about 0.3 to 1.5 mm, particularly about 1.1 mm), it is generally produced by a conventional injection molding method. However, you may manufacture using a photocurable transfer sheet and a stamper. Since the photocurable transfer sheet of the present invention can be thinned to 300 μm or less (preferably 150 μm or less), the other substrate can be produced by a conventional method, and the thickness of the substrate can be increased. Transfer accuracy can be increased.

  In the above step, when pressing the photocurable transfer layer against the substrate or when pressing the stamper against the photocurable transfer layer, it is preferable to press under reduced pressure. Thereby, the removal of bubbles and the like are performed smoothly.

  The pressing under reduced pressure may be performed, for example, by passing a photocurable transfer sheet and a stamper between two rolls under reduced pressure, or using a vacuum forming machine, placing the stamper in a mold and reducing the pressure. Examples thereof include a method in which a photocurable transfer sheet is pressure-bonded to a stamper.

  In addition, pressing under reduced pressure can be performed using a double vacuum chamber type apparatus. This will be described with reference to FIG. FIG. 5 shows an example of a double vacuum chamber type laminator. The laminator includes a lower chamber 54, an upper chamber 52, a silicone rubber sheet 53, and a heater 55. In the lower chamber 54 in the laminator, a laminate 59 of a substrate having unevenness and a photocurable transfer sheet or a laminate 59 of a substrate, a photocurable transfer sheet and a stamper is placed. Both the upper chamber 52 and the lower chamber 54 are evacuated (depressurized). The laminated body 59 is heated by the heater 55, and then the upper chamber 52 is returned to atmospheric pressure while the lower chamber 54 is exhausted, and the laminated body is pressure-bonded. Cool and take out the laminate and move to the next step. Thereby, defoaming is sufficiently performed at the time of exhaust, and the stamper or the substrate and the photocurable transfer sheet can be pressure-bonded without any bubbles.

  The photocurable transfer layer 11 of the photocurable transfer sheet used in the present invention is generally a photocurable composition mainly comprising a polymer and a reactive diluent (polymerizable monomer, oligomer) having a photopolymerizable functional group. It consists of things.

  However, a photocurable transfer sheet having a photocurable transfer layer made of a photocurable composition that can be deformed by pressurization, wherein the photocurable composition is a polymer having a fluorine atom in its molecular structure and photopolymerization. A photocurable transfer sheet comprising a reactive diluent having a functional functional group is novel and is the photocurable transfer sheet of the present invention. As described above, this transfer sheet is advantageously used to form a particularly low refractive index layer of the intermediate resin layer of the optical information recording medium of the present invention.

  The photocurable composition used in the present invention is generally a polymer, a reactive diluent (monomer and oligomer) having a photopolymerizable functional group (generally a carbon-carbon double bond, preferably a (meth) acryloyl group), It is composed of a photopolymerizable initiator and optionally other additives.

  Hereinafter, both a specific photocurable composition advantageous for forming a low refractive index layer used in the transfer sheet of the present invention and a general photocurable composition will be described.

  The specific photocurable composition of the transfer sheet of the present invention uses a polymer having a fluorine atom as the polymer. Furthermore, it is preferable to use a (meth) acrylate having a fluorine atom as a reactive diluent in order to obtain a low refractive index. Examples of the (meth) acrylate having a fluorine atom include fluorine atom-containing monomers such as trifluoroethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate.

  The polymer having a fluorine atom suitable in the present invention is preferably a polymer or copolymer of an acrylic resin having a fluorine atom, particularly a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom. Examples of the (meth) acrylate having a fluorine atom include 2-perfluoroalkylethyl (meth) acrylates such as trifluoroethyl (meth) acrylate and 2-perfluorooctylethyl (meth) acrylate. Other fluorine atom-containing monomers include (perfluoroalkyl) ethylene such as (perfluorooctyl) ethylene with fluorine atoms. As the polymer containing a fluorine atom, a homopolymer of these monomers or a copolymer with other monomers described later can be appropriately used. For example, the refractive index of a trifluoroethyl (meth) acrylate polymer is 1.37.

  In the case of a copolymer of a (meth) acrylate having a fluorine atom and another monomer, the mass ratio of each repeating unit is preferably 90:10 to 50:50, particularly 80:20 to 60:40.

  Examples of the other monomers include (methyl (meth) acrylate ((meth) acrylate means acrylate and methacrylate; the same applies hereinafter), ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) ) Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and other alcohol residues having 2 to 10 carbon atoms (particularly 3 to 5) alkyl (meth) Acrylic acid ester; alkoxyalkyl (meth) acrylate such as ethoxyethyl (meth) acrylate and butoxyethyl (meth) acrylate, alkoxyalkoxyal such as 2-methoxyethoxyethyl (meth) acrylate and 2-ethoxyethoxyethyl (meth) acrylate (Meth) acrylate; alkoxy (such as methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, etc. Poly) alkylene glycol (meth) acrylate; pyrenoxide adduct (meth) acrylate, dialkylaminoalkyl (meth) acrylate such as N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate; 2 -2 to 4 carbon atoms in which an alcohol residue such as hydroxyethyl methacrylate or hydroxypropyl methacrylate styrene has a hydroxyl group Vinyl aromatics such as styrene; (meth) acrylic acid esters of alkyl vinyl acetate; (meth) acrylic acid, maleic acid, fumaric acid, and acid having a vinyl machine such as itaconic acid.

  The acrylic resin containing a sulfur atom is preferably an acrylic resin further having a polymerizable functional group or a hydroxyl group.

  Polymers that can be used in combination with or alone with the above-described polymer containing fluorine atoms include acrylic resins other than those mentioned above, polyvinyl acetate, vinyl acetate / (meth) acrylate copolymers, ethylene / vinyl acetate copolymer Polymer, polystyrene and copolymer thereof, polyvinyl chloride and copolymer thereof, butadiene / acrylonitrile copolymer, acrylonitrile / butadiene / styrene copolymer, methacrylate / acrylonitrile / butadiene / styrene copolymer, 2-chlorobutadiene- 1,3-polymer, chlorinated rubber, styrene / butadiene / styrene copolymer, styrene / isoprene / styrene block copolymer, epoxy resin, polyamide, polyester, polyurethane, cellulose ester, cellulose ether, polycarbonate DOO, and polyvinyl acetal.

  In the present invention, the other polymer is preferably an acrylic resin from the viewpoint of good transferability and excellent curability. The acrylic resin is preferably an acrylic resin having a polymerizable functional group or an acrylic resin having a hydroxyl group.

  The acrylic resin having a polymerizable functional group is generally an acrylic resin having a polymerizable functional group, wherein the alcohol residue has at least one alkyl (meth) acrylate ester having 1 to 10 carbon atoms and glycidyl ( A copolymer of (meth) acrylate, which is obtained by reacting the glycidyl group with a carboxylic acid having a polymerizable functional group, or an alkyl (meth) acrylate having an alcohol residue of 1 to 10 carbon atoms. It is a copolymer of at least one kind and a carboxylic acid having a polymerizable functional group, and the carboxylic acid group is reacted with glycidyl (meth) acrylate.

  In a copolymer of at least one kind of alkyl (meth) acrylic acid ester having an alcohol residue of 1 to 10 carbon atoms and glycidyl (meth) acrylate or the like, by an appropriate combination with a reactive diluent, It becomes easy to achieve both good transferability and excellent curability. Alkyl (meth) acrylic acid esters having 1 to 10 carbon atoms (particularly 3 to 5) of alcohol residues include methyl methacrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) ) Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferred. Further, such a (meth) acrylic acid ester is preferably contained in the polymer as a repeating unit in general in an amount of 5 to 30% by mass, particularly 10 to 30% by mass. The glycidyl (meth) acrylate or carboxylic acid having a polymerizable functional group is preferably contained in the polymer in an amount of generally 5 to 25% by mass, particularly 5 to 20% by mass as the repeating unit. The glycidyl group or carboxylic acid group of the obtained copolymer is reacted with a carboxylic acid or glycidyl (meth) acrylate having a polymerizable functional group, respectively.

  In the case of the acrylic resin having a fluorine atom, a polymerizable functional group can be similarly introduced as described above.

  The acrylic resin having a hydroxyl group generally has at least one alkyl (meth) acrylate ester of an alkyl having 1 to 10 (particularly 1 to 5) carbon atoms and an alcohol residue. It is a copolymer with at least one kind of alkyl (meth) acrylic acid ester having 2 to 4 carbon atoms. Appropriate combination with the reactive diluent makes it easy to achieve both good transferability and excellent curability. Examples of the alkyl (meth) acrylic acid ester having 1 to 10 carbon atoms (particularly 1 to 5) alcohol residues include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, Examples include isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are preferred. Further, such a (meth) acrylic acid ester is preferably contained in the polymer as a repeating unit in general in an amount of 5 to 30% by mass, particularly 10 to 30% by mass. Examples of the alkyl (meth) acrylic acid ester having 2 to 4 carbon atoms in which the alcohol residue has a hydroxyl group include 2-hydroxyethyl methacrylate and hydroxypropyl methacrylate. In general, it is preferably contained in an amount of 5 to 25% by mass, particularly 5 to 20% by mass.

  The (meth) acrylic monomer that can be used as a main component constituting the acrylic resin that includes the above-described fluorine atom, or OH or an acrylic resin having a polymerizable functional group and can be used in the present invention is acrylic acid or Mention may be made of various esters of methacrylic acid. Examples of various esters of acrylic acid or methacrylic acid include methyl (meth) acrylate ((meth) acrylate means acrylate and methacrylate; the same applies hereinafter), ethyl (meth) acrylate, n-propyl (meth) acrylate, n- Alkyl (meta) such as butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, and tridecyl (meth) acrylate ) Acrylate, ethoxyethyl (meth) acrylate, alkoxyalkyl (meth) acrylate such as butoxyethyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate, 2-ethoxyethoxyethyl Alkoxyalkoxyalkyl (meth) acrylates such as meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol ( Dialkylamino such as alkoxy (poly) alkylene glycol (meth) acrylate such as (meth) acrylate, pyrenoxide adduct (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate An alkyl (meth) acrylate etc. can be mentioned. Further, an aromatic compound containing an unsaturated group (eg, styrene) may be used.

  In the present invention, as described above, as the main component of the acrylic monomer, at least one of methyl methacrylate and an alkyl (meth) acrylate having 2 to 10 carbon atoms as an alcohol residue is used. Is preferred.

  The acrylic resin having a hydroxyl group preferably contains 0.1 to 10 mol%, particularly 0.5 to 5 mol% of a hydroxyl group. By using the diisocyanate in combination, it is easy to obtain an appropriate cross-linking that prevents the transfer layer from exuding.

  Furthermore, in the present invention, in order to obtain an intermediate resin layer having a high refractive index (generally 1.60 or more), a polymer containing sulfur atoms (particularly an acrylic resin) can be used as the polymer. Examples of monomers that can be used include phenylthiol (meth) acrylate, naphththiol (meth) acrylate, 4-chlorophenylthiol (meth) acrylate, 4- (meth) acryloxyphenyl-4′-methoxyphenylthioether, and the like. This is preferable. These may be copolymerized with other monomers described above. The refractive index of the phenylthiol acrylate polymer is 1.64, the naphthothiol (meth) acrylate polymer is 1.68, and the 4-chlorophenylthiol acrylate polymer is 1.67. The refractive index of 4-acryloxyphenyl-4′-methoxyphenyl thioether polymer is 1.70, and 4-acryloxyphenyl-4′-methoxyphenyl thioether (70% by mass) and styrene (30% by mass) are combined. The refractive index of the polymer is 1.66, and the refractive index of the 4-methacryloxyphenyl-4′-methoxyphenyl thioether polymer is 1.69, 4-methacryloxyphenyl-4′-methoxyphenyl thioether (70% by mass) The refractive index of the copolymer of styrene and 30% by weight is 1.66.

  The polymer of the present invention preferably has a number average molecular weight of 10,000 or more, particularly 10,000 to 300,000, and a weight average molecular weight of 10,000 or more, particularly 10,000 to 300,000.

  Furthermore, in this invention, the polymer which has both the functional group which has active hydrogens, such as a hydroxyl group, and a photopolymerizable functional group can also be used as a polymer containing a fluorine atom or another polymer. As such a reactive polymer, for example, a homopolymer or a copolymer (that is, an acrylic resin) mainly obtained from the acrylic monomer, and a photopolymerizable functional group and active hydrogen are present in the main chain or side chain. It has a functional group. Therefore, such a reactive polymer is prepared by, for example, coordinating one or more (meth) acrylates with (meth) acrylate having a functional group such as a hydroxyl group (for example, 2-hydroxyethyl (meth) acrylate). It can be obtained by polymerizing and reacting the resulting polymer with a compound having a photopolymerizable group and reacting with a functional group of the polymer, such as isocyanatoalkyl (meth) acrylate. In that case, the polymer which has a hydroxyl group and a photopolymerizable functional group as a functional group which has active hydrogen is obtained by adjusting and using the amount of isocyanatoalkyl (meth) acrylate so that a hydroxyl group may remain.

  Alternatively, in the above, a photopolymerizable functional group having an amino group as a functional group having active hydrogen by using a (meth) acrylate having an amino group instead of a hydroxyl group (eg, 2-aminoethyl (meth) acrylate) A containing polymer can be obtained. Similarly, a photopolymerizable functional group-containing polymer having a carboxyl group or the like as a functional group having active hydrogen can also be obtained.

  In the present invention, an acrylic resin having the photopolymerizable functional group via a urethane bond is also preferable.

  The polymer having a photopolymerizable functional group and a functional group having active hydrogen generally contains 1 to 50 mol%, particularly 5 to 30 mol% of the photopolymerizable functional group. As this photopolymerizable functional group, an acryloyl group, a methacryloyl group, and a vinyl group are preferable, and an acryloyl group and a methacryloyl group are particularly preferable.

  Diisocyanates that can be added to the photocurable composition of the present invention include tolylene diisocyanate (TDI), isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4-diisocyanate, dicyclopentanyl diisocyanate, hexamethylene diisocyanate, 2 4,4'-trimethylhexamethylene diisocyanate and 2,2 ', 4-trimethylhexamethylene diisocyanate. Polyisocyanate cyanates such as trifunctional or higher functional isocyanate compounds such as a TDI adduct of trimethylolpropane can also be used. Of these, a hexamethylene diisocyanate adduct of trimethylolpropane is preferred.

  It is preferable that the diisocyanate of this invention is contained in the photocurable composition in 0.2-4 mass%, especially 0.2-2 mass%. Appropriate crosslinking is provided to prevent the transfer layer from seeping out, and good transferability of the unevenness of the substrate and stamper is also maintained. The reaction between the compound and the polymer proceeds gradually after the transfer layer is formed, and reacts considerably at room temperature (generally 25 ° C.) at 24 hours. It is considered that the reaction proceeds after the coating solution for forming the transfer layer is prepared and before the coating solution is applied. After forming the transfer layer, it is preferable to cure to a certain extent before winding it in the roll state. If necessary, the reaction is promoted by heating during the formation of the transfer layer or before winding in the roll state. You may let them.

  The photocurable composition used in the present invention is generally reactive with the above-described polymers (polymers having fluorine atoms, other polymers) and photopolymerizable functional groups (preferably (meth) acryloyl groups). It is composed of a diluent (monomer and oligomer), a photopolymerizable initiator, and optionally other additives.

As the reactive diluent having a photopolymerizable functional group constituting the photocurable composition used in the present invention, for example,
Fluorine atom-containing monomers such as trifluoroethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate;
It has a sulfur atom and an aromatic ring in the molecule such as phenylthiol (meth) acrylate, naphththiol (meth) acrylate, 4-chlorophenylthiol (meth) acrylate, 4- (meth) acryloxyphenyl-4′-methoxyphenylthioether, etc. (Meth) acrylate;
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-ethylhexyl polyethoxy (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, phenyl Oxyethyl (meth) acrylate, tricyclodecane mono (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acryloylmorpholine, N-vinylcaprolactam, 2-hydroxy-3-phenyloxy Propyl (meth) acrylate, o-phenylphenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol dipro Xidi (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, tri (Meth) acrylates such as methylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, ditrimethylolpropane tetra (meth) acrylate Monomers;
Polyol compounds (for example, ethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butyl-1, Polyols such as 3-propanediol, trimethylolpropane, diethylene glycol, dipropylene glycol, polypropylene glycol, 1,4-dimethylolcyclohexane, bisphenol A polyethoxydiol, polytetramethylene glycol, the polyols and succinic acid, maleic acid Polyester polyols which are reaction products of polybasic acids such as itaconic acid, adipic acid, hydrogenated dimer acid, phthalic acid, isophthalic acid, terephthalic acid, etc., or their acid anhydrides, and the above-mentioned polyols and ε-capro Polycaprolactone polyols which are reactants with kuton, reaction products of the above-mentioned polyols with the above-mentioned polybasic acids or ε-caprolactone of these acid anhydrides, polycarbonate polyols, polymer polyols, etc.) and organic polyisocyanates (for example, , Tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dicyclopentanyl diisocyanate, hexamethylene diisocyanate, 2,4,4′-trimethylhexamethylene diisocyanate, 2,2 ′, 4- Trimethylhexamethylene diisocyanate) and hydroxyl group-containing (meth) acrylates (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydride) Xylbutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, cyclohexane-1,4-dimethylol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerin di (meth) acrylate, etc.) (Meth) acrylate such as polyurethane (meth) acrylate, bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc. ) Acrylate oligomers and the like. These compounds having a photopolymerizable functional group can be used alone or in combination of two or more. In the present invention, as described above, it is preferable to use (meth) acrylate having a sulfur atom and an aromatic ring in the molecule.

  Among these, compounds having a molecular weight of 1000 or less, more preferably 500 or less, and particularly 200 to 400 are preferable. The amount of the reactive diluent is preferably 20 to 80% by mass, particularly 30 to 70% by mass, particularly 40 to 60% by mass in terms of non-volatile content with respect to the total amount of the photocurable composition. The mass ratio of the polymer to the reactive diluent is generally 100: 40 to 160, preferably 100: 60 to 140, and particularly preferably 100: 80 to 120. By setting in this way, it becomes easy to set the glass transition temperature after irradiation with 300 mJ of ultraviolet light to 65 ° C. or higher.

  As the photopolymerization initiator, any known photopolymerization initiator can be used, but one having good storage stability after blending is desirable. Examples of such photopolymerization initiators include benzoin series such as acetophenone series and benzyldimethyl ketal, thiophenone series such as benzophenone series, isopropylthioxanthone, and 2-4-diethylthioxanthone, and other special types include methylphenylglycol. Oxylate can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may contain one or two or more kinds of known and commonly used photopolymerization accelerators such as benzoic acid-based or tertiary amine-based compounds such as 4-dimethylaminobenzoic acid as required. Can be mixed and used. Moreover, it can be used by 1 type, or 2 or more types of mixture of only a photoinitiator. In general, the photocurable composition preferably contains a photopolymerization initiator in an amount of 0.1 to 20% by mass, particularly 1 to 10% by mass.

  Among the photopolymerization initiators, examples of the acetophenone-based polymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone, and 2-hydroxy-2. -Methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methyl Propan-1-one, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2 As benzophenone polymerization initiators such as morpholinopropane-1, Benzophenone, benzoyl benzoate, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, etc. 3,3'-dimethyl-4-methoxybenzophenone may be used.

  As the acetophenone-based polymerization initiator, in particular, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2 -Morpholinopropane-1 is preferred. As the benzophenone polymerization initiator, benzophenone, benzoylbenzoic acid, and methyl benzoylbenzoate are preferable. Tertiary amine photopolymerization accelerators include triethanolamine, methyldiethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate. , Ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate and the like can be used. Particularly preferably, as the photopolymerization accelerator, ethyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate (n-butoxy), isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, etc. Is mentioned.

  In the photocurable transfer layer of the present invention, in addition to the reactive diluent having a photopolymerizable functional group and a photopolymerization initiator, it is preferable to add the following thermoplastic resin and other additives as required.

  As another additive, a silane coupling agent (adhesion promoter) can be added. As this silane coupling agent, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Propyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β There are (aminoethyl) -γ-aminopropyltrimethoxysilane and the like, and one of these can be used alone or two or more of them can be used in combination. As for the addition amount of these silane coupling agents, 0.01-5 mass% is enough normally in a photocurable composition.

  Similarly, an epoxy group-containing compound can be added for the purpose of improving adhesiveness. Examples of the epoxy group-containing compound include triglycidyl tris (2-hydroxyethyl) isocyanurate; neopentyl glycol diglycidyl ether; 1,6-hexanediol diglycidyl ether; acrylic glycidyl ether; 2-ethylhexyl glycidyl ether; Examples thereof include phenol glycidyl ether; pt-butylphenyl glycidyl ether; adipic acid diglycidyl ester; o-phthalic acid diglycidyl ester; glycidyl methacrylate; Further, the same effect can be obtained by adding an oligomer containing an epoxy group having a molecular weight of several hundred to several thousand or a polymer having a weight average molecular weight of several thousand to several hundred thousand. The addition amount of these epoxy group-containing compounds is usually 0.1 to 20% by mass in the photocurable composition, and at least one of the above epoxy group-containing compounds can be added alone or as a mixture.

  As another additive, a hydrocarbon resin can be added for the purpose of improving workability such as workability and bonding. In this case, the added hydrocarbon resin may be either a natural resin type or a synthetic resin type. In natural resin systems, rosin, rosin derivatives, and terpene resins are preferably used. For rosin, gum-based resins, tall oil-based resins, and wood-based resins can be used. As the rosin derivative, rosin obtained by hydrogenation, heterogeneity, polymerization, esterification, or metal chloride can be used. As the terpene resin, a terpene phenol resin can be used in addition to a terpene resin such as α-pinene and β-pinene. In addition, dammar, corbal and shellac may be used as other natural resins. On the other hand, in the synthetic resin system, petroleum resin, phenol resin, and xylene resin are preferably used. As the petroleum resin, aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin, hydrogenated petroleum resin, pure monomer petroleum resin, and coumarone indene resin can be used. As the phenol resin, an alkyl phenol resin or a modified phenol resin can be used. As the xylene-based resin, a xylene resin or a modified xylene resin can be used.

  Although the addition amount of polymers, such as the said hydrocarbon resin, is selected suitably, 1-20 mass% is preferable normally in a photocurable composition, More preferably, it is 5-15 mass%.

  In addition to the above additives, the photocurable composition of the present invention may contain a small amount of an ultraviolet absorber, an antioxidant, a dye, a processing aid and the like. In some cases, additives such as silica gel, calcium carbonate, and fine particles of silicone copolymer may be included in a small amount.

  The photocurable transfer sheet comprising the photocurable composition of the present invention comprises the polymer, a reactive diluent (monomer and oligomer) having a photopolymerizable functional group, a diisocyanate cyanate, and optionally other additives. Can be uniformly mixed and kneaded with an extruder, roll or the like, and then formed into a predetermined shape by a film forming method such as calendering, roll, T-die extrusion or inflation. When using a support, it is necessary to form a film on the support. More preferably, the photocurable adhesive film-forming method of the present invention is obtained by uniformly mixing and dissolving each constituent component in a good solvent, and then applying this solution to a separator precisely coated with silicone or fluororesin. , A gravure roll method, a Myer bar method, a lip die coating method or the like, and a method of forming a film by drying a solvent.

  The thickness of the photocurable transfer sheet is preferably 1 to 1200 μm, particularly preferably 5 to 500 μm. In particular, when producing a multilayer optical information recording medium, 5 to 30 μm, particularly 5 to 20 μm is preferable. If it is thinner than 1 μm, the sealing performance is poor, and the unevenness of the transparent resin substrate may not be filled. On the other hand, if the thickness is greater than 1200 μm, the thickness of the recording medium increases, which may cause problems in the storage and assembly of the recording medium, and may also affect the light transmission.

  It is preferable that release sheets are attached to both sides of the photocurable transfer sheet.

  As a material for the release sheet, a transparent organic resin having a glass transition temperature of 50 ° C. or higher is preferable. As such a material, polyester resins such as polyethylene terephthalate, polycyclohexylene terephthalate, polyethylene naphthalate, nylon 46, modified In addition to polyamide resins such as nylon 6T, nylon MXD6, polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, sulfone resins such as polysulfone and polyether sulfone, polyether nitrile, polyarylate, Use a transparent resin substrate mainly composed of an organic resin such as polyetherimide, polyamideimide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride, etc. Can. Of these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 30 to 100 μm.

  As a material for the substrate 21 having irregularities on the surface, a transparent organic resin having a glass transition temperature of 50 ° C. or higher is preferable. Examples of such a support include polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate. Besides polyester resins, nylon 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, and sulfone resins such as polysulfone and polyether sulfone Organic resin such as polyether nitrile, polyarylate, polyether imide, polyamide imide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride It can be used transparent resin substrate that. Among these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in terms of transferability and birefringence, and can be suitably used. The thickness is preferably 200 to 2000 μm, particularly preferably 500 to 1500 μm.

  The organic polymer film material 26 is preferably a transparent organic resin having a glass transition temperature of 50 ° C. or higher. Examples of such a support include polyester resins such as polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate, and nylon. 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, polysulfone, sulfone resins such as polyether sulfone, polyether nitrile, Transparent tree mainly composed of organic resins such as polyarylate, polyetherimide, polyamideimide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride Substrate can be used. Among these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in terms of transferability and birefringence, and can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 50 to 100 μm.

  The photocurable transfer sheet thus obtained in the present invention preferably further has a light transmittance of 70% or more in the wavelength region of 380 to 420 nm of the photocurable transfer layer.

  The photocurable transfer sheet has a light transmittance of 70% or more in a wavelength region of 380 to 420 nm (preferably 380 to 800 nm), in order to prevent a decrease in intensity of a read signal by a laser. Furthermore, the light transmittance in the wavelength region of 380 to 420 nm is preferably 80% or more.

  Since the photocurable transfer sheet of the present invention can be provided in the form of a film whose film thickness accuracy is precisely controlled, it is possible to easily and accurately bond the substrate and the stamper. In addition, this bonding can be carried out at 20 to 100 ° C. by a simple method such as a pressure roll or a simple press, and then cured by light at room temperature for 1 to several tens of seconds. Since it is difficult for displacement and peeling to occur in the laminate, it has a feature that it can be handled freely until photocuring.

When the photocurable transfer sheet of the present invention is cured, many light sources that emit light in the ultraviolet to visible region can be used as the light source, for example, ultrahigh pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, Mercury halogen. A lamp, a carbon arc lamp, an incandescent lamp, a laser beam, etc. are mentioned. The irradiation time is not generally determined depending on the type of the lamp and the intensity of the light source, but is about 0.1 to several tens of seconds, preferably 0.5 to several seconds. The ultraviolet irradiation amount is preferably 300 mJ / cm ² or more.

  In order to accelerate curing, the laminate may be preheated to 30 to 80 ° C. and irradiated with ultraviolet rays.

  The obtained reflective layer on the uneven surface of the substrate of the present invention is formed by metal deposition (for example, sputtering, vacuum deposition, ion plating, etc.) of the reflective layer on the substrate. As a metal, aluminum, gold | metal | money, silver, these alloys (preferably silver alloy) etc. can be mentioned. The translucent reflective layer on the cured sheet is formed using silver or the like as a metal. That is, it is necessary to make the reflective layer have a lower reflectance than the reflective layer, and the components, film thickness, and the like are changed.

When an organic polymer film is pasted on the reflective layer of the cured sheet, an adhesive is applied on one side, and the other is stacked thereon and cured. When the adhesive is a UV curable resin, it is obtained by UV irradiation, and when it is a hot melt adhesive, it is obtained by applying and cooling under heating.
The production of the optical information recording medium of the present invention is usually processed in a disc shape as described above, but it may be made continuously in a sheet shape and finally in a disc shape.

  The following examples further illustrate the present invention.

[Example 1]
<Preparation of Photocurable Transfer Sheet A>
(Production of polymer 1)
Polymer blend 1
Benzyl methacrylate 83.1 parts by mass 2-hydroxyethyl methacrylate 16.9 parts by mass AIBN 5 parts by mass Toluene 30 parts by mass Ethyl acetate 70 parts by mass

  The mixture having the above composition was heated to 70 ° C. with gentle stirring to initiate polymerization, and stirred at this temperature for 8 hours to obtain Polymer 1 (acrylic resin) having a hydroxyl group in the side chain. The solid content was adjusted to 50% by mass (polymer solution 1).

  The obtained polymer 1 had a refractive index of 1.50, a Tg of 55 ° C., and a weight average molecular weight of 20000.

Composition formulation 1
Polymer solution 1 100 parts by mass Dimethylol tricyclodecane diacrylate (DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.) 40 parts by mass Diisocyanate (BXX5627, manufactured by Toyo Ink Manufacturing Co., Ltd.) 1 part by mass Irgacure 651
(Ciba Specialty Chemicals) 1 part by weight Hydroquinone monomethyl ether (MEHQ) 0.05 part by weight

  The mixture having the above composition was uniformly dissolved and kneaded, and applied onto the entire surface of a release sheet (width 140 mm, length 300 m, thickness 75 μm; trade name No. 23, manufactured by Fujimori Kogyo Co., Ltd.), and a dry thickness of 25 μm. A photocurable transfer layer was formed, and the same release sheet as above was attached to the opposite side of the sheet and rolled up into a roll to obtain a full edge type roll (diameter 260 mm) of the photocurable transfer sheet. The refractive index of the photocurable transfer layer after curing was 1.50.

<Preparation of Photocurable Transfer Sheet B>
(Production of polymer 2)
Polymer blend 2
t-Butyl methacrylate 81 parts by mass 2-hydroxyethyl methacrylate 19 parts by mass AIBN 5 parts by mass Toluene 30 parts by mass Ethyl acetate 70 parts by mass

  The mixture having the above composition was heated to 70 ° C. with gentle stirring to initiate polymerization, and stirred at this temperature for 8 hours to obtain polymer 2 (acrylic resin) having a hydroxyl group in the side chain. The solid content was adjusted to 50% by mass (polymer solution 2).

  The obtained polymer 2 had a refractive index of 1.42, a Tg of 95 ° C., and a weight average molecular weight of 20000.

Composition formulation 2
Polymer solution 2 100 parts by mass Hexanediol diacrylate (KS-HDDA, manufactured by Kyoeisha Chemical Co., Ltd.) 40 parts by mass Diisocyanate (BXX5627, manufactured by Toyo Ink Manufacturing Co., Ltd.) 1 part by mass Irgacure 651
(Ciba Specialty Chemicals) 1 part by weight Hydroquinone monomethyl ether (MEHQ) 0.05 part by weight

  The mixture having the above composition was uniformly dissolved and kneaded, and applied onto the entire surface of a release sheet (width 140 mm, length 300 m, thickness 75 μm; trade name No. 23, manufactured by Fujimori Kogyo Co., Ltd.), and a dry thickness of 25 μm. A photocurable transfer layer was formed, and the same release sheet as above was attached to the opposite side of the sheet and rolled up into a roll to obtain a full edge type roll (diameter 260 mm) of the photocurable transfer sheet. The refractive index of the photocurable transfer layer after curing was 1.43.

<Preparation of photocurable transfer sheet C>
(Production of polymer 3)
Polymer blend 3
Trifluoroethyl methacrylate 80 parts by mass 2-hydroxyethyl methacrylate 20 parts by mass AIBN 5 parts by mass Toluene 30 parts by mass Ethyl acetate 70 parts by mass

  The mixture having the above composition was heated to 70 ° C. with gentle stirring to initiate polymerization, and stirred at this temperature for 8 hours to obtain Polymer 3 (acrylic resin) having a hydroxyl group in the side chain. The solid content was adjusted to 50% by mass (polymer solution 3).

  The obtained polymer 3 had a refractive index of 1.37, a Tg of 44 ° C., and a weight average molecular weight of 20000.

Composition 3
Polymer solution 3 100 parts by mass Trifluoroethyl methacrylate (M-3F, manufactured by Kyoeisha Chemical Co., Ltd. ) 40 parts by mass Diisocyanate (BXX5627, manufactured by Toyo Ink Manufacturing Co., Ltd.) 1 part by mass Irgacure 651
(Ciba Specialty Chemicals) 1 part by weight Hydroquinone monomethyl ether (MEHQ) 0.05 part by weight

  The mixture having the above composition was uniformly dissolved and kneaded, and applied onto the entire surface of a release sheet (width 140 mm, length 300 m, thickness 75 μm; trade name No. 23, manufactured by Fujimori Kogyo Co., Ltd.), and a dry thickness of 25 μm. A photocurable transfer layer was formed, and the same release sheet as above was attached to the opposite side of the sheet and rolled up into a roll to obtain a full edge type roll (diameter 260 mm) of the photocurable transfer sheet. The refractive index of the photocurable transfer layer after curing was 1.37.

<Production of optical information recording medium>
After punching out the roll of the photocurable transfer sheet C into a disk shape, one release sheet is removed, and the obtained disk-shaped photocurable transfer sheet is a polycarbonate substrate having uneven surfaces as pits formed by injection molding Placed on the silver alloy reflective layer (90 nm) provided on the uneven surface (thickness 1.1 mm), the transfer sheet surface and the reflective layer are in contact, and a load of 2 kg using a roller made of silicone rubber Then, the photocurable transfer sheet was pressed to form a laminate.

  Remove the other release sheet of the photo-curing transfer sheet of the laminate, and contact the surface of the removed transfer sheet with a nickel stamper with a concavo-convex surface as a pit, with the concavo-convex surface of the stamper The stamper was pressed with a load of 2 kg using a silicone rubber roller to form a laminate, and the uneven shape of the stamper was transferred to the transfer sheet surface.

Next, from the photocurable transfer sheet side, UV irradiation was performed using a metal halide lamp (600 mW / cm) through a silver alloy transflective layer under the condition of an integrated light quantity of 300 mJ / cm ² (irradiation distance 20 cm, An irradiation time of 1.0 sec) was formed, and a first intermediate resin layer (intermediate layer) (11a in FIG. 1) having a thickness of 10 μm was formed by curing the transfer sheet. Next, a silver alloy reflective layer (70 nm) was formed by sputtering a silver alloy on the uneven surface of the cured photocurable transfer layer.

  On the said silver alloy reflective layer, the photocurable transfer sheet B was pressed like the above, and the laminated body was formed. The other release sheet of the photocurable transfer sheet of the laminate is removed, and a stamper is pressed onto the removed transfer sheet surface in the same manner as described above to form a laminate, and the uneven shape of the stamper is formed on the transfer sheet surface. Transcribed to. Next, from the photocurable transfer sheet side, UV irradiation was performed in the same manner as described above to form a second intermediate resin layer (intermediate layer) (11b in FIG. 1) having a thickness of 10 μm, which cured the transfer sheet. A thin silver alloy reflective layer (50 nm) was formed by peeling and removing the stamper from the laminate and sputtering a silver alloy on the uneven surface of the cured photocurable transfer sheet.

  Furthermore, the photocurable transfer sheet A was pressed on the above semitransparent reflective layer of the silver alloy provided on the uneven surface to form a laminate. The other release sheet of the photocurable transfer sheet of the laminate is removed, and a stamper is pressed onto the removed transfer sheet surface in the same manner as described above to form a laminate, and the uneven shape of the stamper is formed on the transfer sheet surface. Transcribed to. Next, from the photocurable transfer sheet side, UV irradiation was performed in the same manner as described above to form a second intermediate resin layer (intermediate layer) (11c in FIG. 1) having a thickness of 10 μm by curing the transfer sheet. A thin silver alloy reflective layer (30 nm) was formed by peeling and removing the stamper from the laminate and sputtering a silver alloy on the uneven surface of the cured photocurable transfer sheet.

  A polycarbonate film (thickness 70 μm; trade name Pure Ace C110-70, manufactured by Teijin Ltd.) was pasted thereon via an adhesive.

Thus, an optical information recording medium having four layers of uneven surfaces was obtained.
[Comparative Example 1]
In the production of the optical information recording medium, the three types of sheets of the photocurable transfer sheets A, B and C used in Example 1 were all used as the intermediate resin layer (layer) using the photocurable transfer sheet B. An optical information recording medium having four layers of uneven surfaces was prepared in the same manner except that three layers (thickness: 10 μm) were provided.

(1) Evaluation of photocurable transfer sheet (1-1) Measurement of refractive index It measured according to JIS-K-7142-1996.
(1-2) Measurement of glass transition temperature (Tg) The release sheets on both sides were removed from the obtained photocurable transfer sheet, and the sample was cut into a length of 20 mm and a width of 4 mm (thickness 25 μm).

Using a TMA (Thermal Mechanical Analysis) apparatus SS6100 (manufactured by SII Nanotechnology Co., Ltd.), Tg of the sample was sample temperature: 30 to 120 ° C., temperature rising rate: 5 ° C./min, tensile tension: 4.9 × The measurement was performed at 10 ⁵ Pa.

  When the test was performed under the above conditions, the graph shown in FIG. 6 was obtained, and the intersection of the tangent line of the stable region and the tangent line from the maximum slope of the stretch region was defined as the glass transition temperature.

(1-3) Measurement of weight average molecular weight The weight average molecular weight of the polymer obtained by the said Example and the comparative example was measured using the gel permeation chromatography (HLC-8220GPC; Tori Co., Ltd. product).

(2) Evaluation of the obtained optical information recording medium (2-1) Measurement of glass transition temperature (Tg) A sample obtained in the same manner as in (1-1) was subjected to UV under the condition of an integrated light quantity of 300 mJ / cm ^2. Irradiation was performed and Tg was measured in the same manner as in (1-1).

The integrated light quantity (300 mJ / cm ² ) was measured on the surface of the layer using UV Power Pack (UV-A band measurement) manufactured by Fusion UV Systems Japan Co., Ltd.

(2-2) Jitter The jitter of the pit signal of the obtained optical information recording medium was measured using a time interval analyzer TA723 (manufactured by Yokogawa Electric Corporation). Evaluation was performed as follows.

○: Less than 7.0% ×: 7.0% or more.

  The test results obtained are shown in Table 1.

Remarks) Ref .: Refractive index
L0: Recording surface on substrate
L1: First intermediate resin layer recording surface
L2: Second intermediate resin layer recording surface
L3: Third intermediate resin layer recording surface

  The four-layer optical information recording medium using the photocurable transfer sheet obtained in Example 1 exhibited low jitter even though the intermediate resin layer was thin. A conventional four-layer type optical information recording medium using an intermediate resin layer having the same refractive index cannot obtain a sufficiently low jitter.

It is sectional drawing which shows an example of the optical information recording medium according to this invention. It is sectional drawing which shows an example of embodiment of the photocurable transfer sheet according to this invention. It is sectional drawing which shows an example of the manufacturing method of the multilayer type | mold optical information recording medium according to this invention. FIG. 4 is a cross-sectional view showing a process following FIG. 3 in the method for manufacturing a multilayer optical information recording medium according to the present invention of FIG. 3. It is this schematic for demonstrating the press method using the apparatus of a double vacuum chamber system. It is a graph which shows the measuring method of the glass transition temperature in an Example. It is sectional drawing of the conventional optical information recording medium.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photocurable transfer sheet 11 Photocurable transfer layer 11a, 11b, 11c Cured photocurable transfer layer (intermediate resin layer)
12a, 12b Release sheet 21 Substrate 23a, 23b, 23c, 23d Reflective layer 24 Stamper 26 Organic polymer film (cover layer)

Claims (25)

On the surface of the optical information recording substrate having irregularities as recording pits and / or grooves and further having a reflective layer formed on the irregular surface, irregularities as recording pits and / or grooves are formed on the surface. The intermediate resin layer having a reflective layer formed on the uneven surface of the intermediate resin layer has the uneven surface of the intermediate resin layer opposed to the reflective layer of the substrate surface, and the unevenness on the reflective layer of the substrate surface. Further, one or more other intermediate resin layers having a concavo-convex surface and a reflective layer are provided so that the surface having no concavo-convex surface of the intermediate resin layer faces the reflective layer of the intermediate resin layer already provided. An optical information recording medium provided on the reflective layer of the intermediate resin layer already provided along the unevenness thereof,
An optical information recording medium characterized in that at least two adjacent layers of the intermediate resin layer have different refractive indexes.   The optical information recording medium according to claim 1, wherein the intermediate resin layer is a cured layer of a photocurable composition containing a polymer and a reactive diluent having a photopolymerizable functional group.   The optical information recording medium according to claim 2, wherein the polymer of at least one intermediate resin layer is a polymer having a fluorine atom in the molecular structure.   4. The optical information recording medium according to claim 2, wherein the polymer of the intermediate resin layer closest to the transparent substrate is a polymer having a fluorine atom in the molecular structure.   The optical information recording medium according to any one of claims 2 to 4, wherein the polymer having a fluorine atom is an acrylic resin.   The optical information recording medium according to claim 5, wherein the acrylic resin is a polymer or copolymer of a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom.   The optical information recording medium according to claim 6, wherein the acrylic resin is a copolymer of (meth) acrylate having a fluorine atom and (meth) acrylate having a hydroxyl group.   The optical information recording medium according to claim 2, wherein the reactive diluent having a photopolymerizable functional group contains (meth) acrylate having a fluorine atom.   The optical information recording medium according to any one of claims 2 to 8, wherein the photocurable composition further contains diisocyanate.   The optical information recording medium according to any one of claims 2 to 9, wherein the photocurable composition contains 0.1 to 10% by mass of a photopolymerization initiator.   The optical information recording medium according to any one of claims 1 to 10, wherein the light transmittance in the wavelength region of 380 to 420 nm of the intermediate resin layer is 70% or more.   The optical information recording medium according to any one of claims 1 to 14, wherein the light transmittance in a wavelength region of 380 to 800 nm of the intermediate resin layer is 70% or more.   The optical information recording medium according to claim 1, wherein the intermediate resin layer has a thickness of 5 to 300 μm.   The photocurable transfer sheet according to any one of claims 1 to 13, wherein the refractive index of at least one of the intermediate resin layers is 1.42 or less.   The optical information recording medium according to claim 1, wherein a difference in refractive index between adjacent intermediate resin layers is 0.02 or more.   The optical information recording medium according to claim 1, wherein a protective layer is provided on the reflective layer of the uppermost intermediate resin layer. The following steps (2) to (4):
(2) It has a photocurable transfer layer made of a photocurable composition that can be deformed by pressurization, and a release sheet is provided on one or both surfaces of the photocurable transfer layer. A step of removing one release sheet of the photocurable transfer sheet when the release sheet is provided on both sides thereof;
(3) Photocuring of the photocurable transfer sheet on the reflective layer of the substrate having irregularities as recording pits and / or grooves on the surface and further provided with a reflective layer along the irregularities on the irregular surface. A laminate in which the surface of the light-sensitive transfer layer is placed in contact with the uneven surface of the reflective layer, and the surface of the photocurable transfer sheet is adhered along the uneven surface of the reflective layer by pressing them. A step of forming; and (4) a step of removing the other release sheet from the laminate,
(5) The irregular surface of the stamper having irregularities as recording pits and / or grooves is placed on the surface of the photocurable transfer layer from which the release sheet of the laminate has been removed, and these are pressed to press the light. Forming a laminate in which the surface of the curable transfer sheet is adhered along the uneven surface;
(6) A step of providing irregularities on the surface of the photocurable transfer layer by curing the photocurable transfer layer of the laminate having the stamper by ultraviolet irradiation and then removing the stamper;
(7) providing a reflective layer on the uneven surface of the photocurable transfer layer;
(8) The surface of the photocurable transfer layer of the photocurable transfer sheet having a photocurable transfer layer having a refractive index different from the refractive index of the already cured photocurable transfer layer on the reflective layer is Placing the surface so as to be in contact with the uneven surface of the reflective layer and pressing them to form a laminate in which the surface of the photocurable transfer sheet is adhered along the uneven surface of the reflective layer;
(9) removing the other release sheet from the laminate;
(10) The irregular surface of the stamper having irregularities as recording pits and / or grooves is placed on the surface of the photocurable transfer layer from which the release sheet of the laminate has been removed, and these are pressed to press the light. Forming a laminate in which the surface of the curable transfer sheet is adhered along the uneven surface;
(11) A step of providing irregularities on the surface of the photocurable transfer layer by curing the photocurable transfer layer of the laminate having the stamper by ultraviolet irradiation and then removing the stamper;
(12) A step of providing a reflective layer on the uneven surface of the photocurable transfer layer;
And (8) to (12) are performed at least once. A photocurable transfer sheet having a photocurable transfer layer made of a photocurable composition that can be deformed by pressurization,
A photocurable transfer sheet, wherein the photocurable composition contains a polymer having a fluorine atom in a molecular structure and a reactive diluent having a photopolymerizable functional group.   The optical information recording medium according to claim 18, wherein the polymer having a fluorine atom is an acrylic resin.   The photocurable transfer sheet according to claim 19, wherein the acrylic resin is a polymer or copolymer of a (meth) acrylate monomer containing a (meth) acrylate having a fluorine atom.   The photocurable transfer sheet according to claim 19 or 20, wherein the acrylic resin is a copolymer of (meth) acrylate having a fluorine atom and (meth) acrylate having a hydroxyl group.   The photocurable transfer sheet according to any one of claims 19 to 21, wherein the reactive diluent having a photopolymerizable functional group contains a (meth) acrylate having a fluorine atom.   The photocurable transfer sheet according to any one of claims 19 to 22, wherein the photocurable composition further contains a diisocyanate.   The photocurable transfer sheet according to any one of claims 19 to 23, wherein the photocurable composition contains 0.1 to 10% by mass of a photopolymerization initiator.   The refractive index of a photocurable transfer layer is 1.42 or less, The photocurable transfer sheet of any one of Claims 19-24.

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