JP2003272228A - Photo-curing transfer sheet and its manufacturing method, laminated body, optical information recording substrate and optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium in which precise pit signals and/or grooves are formed and which has an opposite side surface (laser irradiation side) having excellent smoothness. <P>SOLUTION: The optical information recording medium has a curable coating film of a photo-curing transfer sheet which contains a reactive polymer having a photopolymerizable functional group and which consists of photo-curing composition deformable by pressure. Surface roughness Ra of the opposite side surface to the rugged surface of the curable coating film is ≤30 nm. Otherwise a surface smoothening layer being a curable coating film of an applied layer of a UV setting resin is disposed on the surface of the opposite side to the rugged surface of the curable coating film and further surface roughness Ra of this layer is ≤30 nm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to a DVD (Digital
Versatile Disc), CD (Compact Disc), and other large-capacity characters, audio, moving image information and / or recordable as an optical information recording medium, optical information recording medium substrate, and manufacturing thereof The present invention relates to a method, a photocurable transfer sheet and a laminate which are useful for producing this substrate.

[0002]

2. Description of the Related Art Audio CDs and CD-ROMs have been widely used as recorded optical information recording media having pits formed on their surfaces as digital signals, but recently, they have been able to record moving images on both sides. DV with pit recording
D has attracted attention as a next-generation recording medium for CDs and is gradually being used. In addition, a CD with pits and / or grooves that can be recorded by the user
R, DVD-R, DVD-RW, etc. are also receiving attention.

For a DVD having recording layers on both sides, for example, as shown in FIG.
Reflective layers 1a and 2a are respectively formed on the signal bit forming surfaces of the transparent resin substrates 1 and 2 and these reflective layers 1a and 2a are formed.
The substrates 1 and 2 are bonded to each other via the adhesive layer 3 in a state of facing each other, and the double-sided read method is used, and as shown in FIG. 7, the substrates 1 and 1 each have a signal bit formed on one side thereof. 2, a translucent layer 1b is formed on the signal bit surface of one of the substrates 1 and a reflective layer 2a is formed on the signal bit surface of the other substrate 2, and these translucent layers 1b are formed.
It is known that the substrates 1 and 2 are adhered to each other with the adhesive layer 3 in the state where the reflective layer 2a and the reflective layer 2a face each other, and are joined together.

Conventionally, a double-sided read DVD is manufactured by, for example, using a stamper in which the irregularities of the signal pits are opposite male and female, melting a polycarbonate resin, and injection molding the transparent resin substrate having irregularities on the surface. Then, a reflective layer is formed by depositing a metal such as aluminum on the uneven surface by sputtering or the like,
This is done by bonding two transparent resin substrates having the reflective layer formed thereon with the reflective layers facing each other with an adhesive.

[0005]

As described above, the DVD
The transparent resin substrate (optical information recording substrate) is obtained by injection molding of polycarbonate using a stamper. The pit formation by such injection molding has a thickness of 300
In the case of a thin substrate having a thickness of μm or less, there is a problem that the accuracy of transferring the pit shape from the stamper to the polycarbonate resin is lowered (see Japanese Patent Laid-Open No. 11-273147). Then, the present inventors have also found a problem that the land portions of the pits and the grooves become rough surfaces.

With the increase in the amount of information to be recorded, it is expected that a new optical information recording medium having a larger storage capacity than the currently used DVD will appear. To achieve that, not only make the signal pits and grooves smaller,
It is also necessary to shorten the wavelength of the reproducing laser (or writing laser) for signal reading, and the shorter wavelength shortens the distance to the pit surface.
It is also necessary to reduce the thickness of the optical information recording medium.

In Japanese Patent Laid-Open No. 11-273147, a pressure-sensitive adhesive sheet or a dry photopolymer is used in addition to an ultraviolet curable resin in order to bond an injection-molded substrate having irregularities on its surface and a transparent film. However, it is described that the dry photopolymer has low transparency and is not preferable. For this reason, there is no suggestion of using a dry photopolymer for forming irregularities on the surface.

In view of the above, the present application allows for easy and accurate transfer by pressing on the uneven surface of the stamper for making a substrate of the optical information recording medium, and particularly 300 μm.
The following thin substrates can be advantageously obtained, and a photo-curable transfer sheet with a small curing shrinkage has already been applied for (Japanese Patent Application No. 20).
01-305946). However, although such a transfer sheet has a small curing shrinkage, it may not be said that the surface smoothness is sufficient. The surface on the opposite side of the substrate on which the unevenness is not formed is the side on which the laser for recording or reproduction is irradiated, and if the unevenness of this surface is large, errors easily occur in recording and reproduction.

The present invention made in view of the above points enables simple and accurate transfer by pressing on the uneven surface of the stamper for producing a substrate of the optical information recording medium, and particularly, advantageously obtains a thin substrate of 300 μm or less. It is an object of the present invention to provide a photocurable transfer sheet which can be formed and has good surface smoothness.

It is also an object of the present invention to provide a method for producing the above photocurable transfer sheet.

Furthermore, it is an object of the present invention to provide an optical information recording substrate suitable for producing an optical information recording medium in which the uneven surface of the stamper is accurately transferred and the surface (the laser irradiation side) on the opposite side is excellent in smoothness. And

Furthermore, an accurate pit signal and / or groove is formed, and the opposite surface (laser irradiation side).
It is an object of the present invention to provide an optical information recording medium having excellent smoothness.

[0013]

Accordingly, the present invention comprises a photocurable composition which comprises a reactive polymer having photopolymerizable functional groups and which is deformable by pressure and which has a surface roughness of at least one surface. The Ra is 30 nm or less (preferably 10 nm or less) in the photocurable transfer sheet.

In the above photocurable transfer sheet, the glass transition temperature of the photocurable composition is preferably 20 ° C. or lower. This makes it easy to form irregularities by pressing at room temperature. The photocurable transfer sheet has a wavelength range of 380 to 420 nm (preferably 380 to 600 nm, particularly 380).
It is preferable that the light transmittance in a wavelength region of up to 800 nm) is 70% or more. When a signal is read by a laser on the resulting medium, error-free operation is guaranteed. Curing shrinkage of the photocurable transfer layer is 8%
The following is preferable.

The reactive polymer has 1 to 1 photopolymerizable functional groups.
It is preferable to contain 50 mol% in order to obtain appropriate curability and cured film strength. The photopolymerizable functional group is preferably a (meth) acryloyl group from the viewpoint of curability. The photocurable composition preferably contains the photopolymerization initiator in an amount of 0.1 to 10% by mass in order to obtain appropriate curability. The thickness of the photocurable transfer layer is preferably 5 to 300 μm from the viewpoint of transferability and workability.

The photocurable transfer sheet contains a reactive polymer having a photopolymerizable functional group and has a surface roughness Ra of 30 nm or less in a molten state of a photocurable composition which is deformable by pressure. By casting on the surface of the support; or a coating solution containing a photocurable composition that contains a reactive polymer having a photopolymerizable functional group and can be deformed by pressure, a surface roughness Ra of 30 nm. The following can be advantageously obtained by coating on the surface of the support and drying.

The present invention also provides a laminate in which the photocurable transfer sheet is closely adhered to the uneven surface of a stamper having unevenness on the surface as recording pits and / or grooves, along the uneven surface.

Furthermore, the present invention is an optical information recording substrate comprising a cured coating of the above-mentioned photocurable transfer sheet, wherein one surface of the cured coating has irregularities as recording pits and / or grooves. An optical information recording substrate, characterized in that the surface roughness Ra of the surface opposite to the uneven surface of the cured coating is 30 nm or less; unevenness as recording pits and / or grooves is formed on the surface and is formed on the uneven surface. The optical information recording substrate having the reflective layer formed thereon and the optical information recording substrate having the semi-transparent reflective layer formed on the surface of the unevenness having the unevenness as recording pits and / or grooves Are opposed to each other and are bonded together via an adhesive layer, wherein at least one substrate is composed of a cured coating of the photocurable transfer sheet, and has an uneven surface of the cured coating. Surface roughness Ra of the contralateral surface 30
an optical information recording medium characterized by having a size of not more than nm; and having irregularities as recording pits and / or grooves on the surface,
An optical information recording substrate having a reflective layer formed on the uneven surface, and an optical information recording substrate having unevenness as recording pits and / or grooves on the surface and having a semitransparent reflecting layer formed on the uneven surface. An optical information recording medium comprising the former semi-transparent reflective layer bonded to the surface without a reflective layer via an adhesive layer, wherein at least one substrate is a cured film of the photocurable transfer sheet. And an optical information recording medium characterized in that the surface roughness Ra of the surface of the cured coating opposite to the concavo-convex surface is 30 nm or less.

Further, the present invention comprises a cured coating of a photocurable transfer sheet comprising a photocurable composition containing a reactive polymer having a photopolymerizable functional group and deformable by pressurization. An optical information recording substrate having irregularities as recording pits and / or grooves formed on one surface, and a surface smoothing layer which is a cured coating of a coating layer of an ultraviolet curable resin on a surface opposite to the irregular surface. An optical information recording substrate which is formed and has a surface roughness Ra of 30 nm or less; a reflective layer formed on the uneven surface having unevenness as recording pits and / or grooves. Optical information recording substrate having and recording pits and / or
Alternatively, an optical information recording having an unevenness as a groove and an optical information recording substrate having a semitransparent reflective layer formed on the uneven surface, and bonding the reflective layers to each other with an adhesive layer therebetween. A medium, wherein at least one substrate is
A cured coating of a photocurable transfer sheet comprising a photocurable composition containing a reactive polymer having a photopolymerizable functional group and capable of being deformed under pressure, wherein the surface of the cured coating opposite to the uneven surface is exposed to ultraviolet rays. An optical information recording medium provided with a surface smoothing layer which is a cured film of a coating layer of a curable resin and having a surface roughness Ra of 30 nm or less.
An optical information recording substrate having irregularities as recording pits and / or grooves on the surface and a reflective layer formed on the irregularities surface, and irregularities as recording pits and / or grooves on the surface, and the irregular surface An optical information recording substrate having a semitransparent reflective layer formed in, the optical information recording medium formed by bonding the latter semitransparent reflective layer to the surface without a reflective layer of the former via an adhesive layer, At least one of the substrates, a layer including at least the uneven surface is a cured film of a photocurable transfer sheet comprising a photocurable composition containing a reactive polymer having a photopolymerizable functional group and deformable by pressure. A surface smoothing layer, which is a cured coating of a coating layer of an ultraviolet curable resin, is provided on the surface of the cured coating opposite to the uneven surface, and the surface roughness Ra of this layer is 30 nm or less. Information recording medium; in.

In the above optical information recording medium, the surface roughness R
It is preferable that a is 10 nm or less. The glass transition temperature of the photocurable composition is preferably 20 ° C. or lower. 380-420n of cured film of photocurable transfer sheet
The light transmittance in the wavelength region of m is preferably 70% or more, and the light transmittance in the wavelength region of 380 to 800 nm is 70% or more.
% Or more is preferable. The reactive polymer preferably contains 1 to 50 mol% of a photopolymerizable functional group. The photopolymerizable functional group is a (meth) acryloyl group, the photocurable composition contains 0.1 to 10% by mass of a photopolymerization initiator, and the thickness of the photocurable transfer sheet is 5 to 300 μm. Is preferred.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIGS. 1A and 1B are sectional views showing an example of an embodiment of the photocurable transfer sheet 11 of the present invention. The photocurable transfer sheet 11 of FIG. 1A has release sheets 12a and 12b on both sides. Only one release sheet may be provided, or no release sheet may be provided. These are appropriately set depending on the usage. The photocurable transfer sheet 11 of FIG. 1B has a release sheet 12a on one surface and a support 12c on the other surface.

The photocurable transfer sheet 11 of the present invention has extremely good surface smoothness and a surface roughness Ra of 30 nm or less, preferably 10 nm or less. The transfer sheet having such a smooth surface has, for example, a photocurable composition which contains a reactive polymer having a photopolymerizable functional group and is deformable by pressurization in a molten state and has a surface roughness Ra of 30 nm.
It is obtained by casting on the surface of a support as described below. Examples of such a support include a film made of polycarbonate, which is generally commercially available. Alternatively, it can also be obtained by applying a coating solution of the photocurable composition onto a support surface having a surface roughness Ra of 30 nm or less (preferably 10 nm or less) and drying. However, the former method is preferable because it is easy to obtain a low surface roughness.

It is preferable that the transfer sheet is mainly composed mainly of a photocurable composition containing a reactive polymer having a photopolymerizable functional group having a glass transition temperature of 20 ° C. or lower. In addition, the light transmittance in the wavelength range of 380 to 420 nm is 70 for easy reading by the reproducing laser.
% Or more. Especially 380
A layer having a light transmittance of 80% or more in the wavelength region of 420 nm is preferable. Further, it is preferable that the cured sheet also has the same transmittance. Therefore, the optical information recording medium of the present invention produced by 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.

Using the above-mentioned photocurable transfer sheet, an optical information recording substrate and a laminated body can be sequentially manufactured, for example, as shown in FIG. 2 below.

When the photo-curable transfer sheet 11 having the release sheets 12a and 12b on both sides is used, one release sheet 12b is removed and the photo-curable transfer sheet is formed on the stamper 21 having surface irregularities as recording pits. 11 is placed so that the surface on the side not having the release sheet and the unevenness face each other, and they are overlapped, and pressed so that the light-curable transfer sheet 11 and the uneven surface are completely adhered to each other.
And a stamper 21 to form a laminate of the present invention.
Then, UV (ultraviolet rays) is irradiated from above the release sheet 12a to cure the photocurable transfer sheet 11. Then, the stamper 21 and the release sheet 12a are removed to obtain the photocurable transfer sheet 20 (that is, the optical information recording substrate) having the cured unevenness of the present invention. The surface of the substrate having no unevenness has a surface roughness Ra of 30 nm or less (preferably 10 nm).
Below).

The release sheet is provided on one surface and the support is provided on the other surface. When the photocurable transfer sheet of FIG. 1 (b) is used, the surface roughness Ra of the support surface of the obtained substrate and both surfaces where the support and the transfer sheet are in contact are 30 nm or less (preferably 10 nm or less). Is.

In the present invention, the photo-curable transfer sheet 11 and the stamper 21 are formed into a concavo-convex shape which is a recording pit.
The photocurable transfer layer is designed so that it can be accurately transferred by pressing at a low temperature of ℃ or less. Stamper 21
And the photocurable transfer sheet 11 are generally superposed on each other by a pressure roll or a simple press (preferably under reduced pressure). Further, the cured layer of the photocurable transfer sheet 11 has an extremely weak adhesive force to a metal such as nickel used for the stamper, and the photocurable transfer sheet can be easily peeled from the stamper.

The optical information recording substrate 2 thus obtained
0 can be used to manufacture an optical information recording medium as shown in FIG.

A silver alloy reflective layer (semi-transparent reflective layer) 13 is formed by sputtering a silver alloy on the uneven surface of the optical information recording substrate 20 obtained above to form an optical information recording having uneven surface. Aluminum (or a silver alloy reflective layer having a reflectance higher than that of the semitransparent reflective layer) is deposited on the uneven surface of the substrate 30 by sputtering to form an Al reflective layer 33. Then, the optical information recording medium 40 is obtained by stacking them via an adhesive and curing the adhesive to form the adhesive layer 34. The surface of the sheet 11 of the optical information recording medium 40 on the side having no unevenness has a surface roughness Ra of 30 nm or less (preferably 10 nm or less).
Is. Since reading is performed by irradiating the reproducing light (reproducing laser) from the surface side, there is almost no reading error. You may further provide a support body or a protective film on this surface.

In the above method, the read-only optical information recording medium has been described, but in the case of a recordable optical information recording medium, it has grooves or pits and grooves. In this case, the reflective layer and the semitransparent reflection are used. A metal recording layer (a recording layer and a reflective layer in the case of a dye recording layer) is provided instead of the layer. Otherwise, the optical information recording medium can be manufactured in the same manner as above.

Since the optical information recording substrate 30 is generally a thick plate, it may be manufactured by a conventional injection molding method or by the manufacturing method of the optical information recording substrate of the present invention.
Since the optical information recording substrate of the present invention can be a thin substrate having a thickness of 300 μm or less, the thickness of the substrate can be increased when the other substrate is manufactured by the conventional method. The transfer accuracy can be improved. As the adhesive for forming the adhesive layer, any of conventional hot-melt adhesives, UV-curable resin adhesives and pressure-sensitive adhesives can be used.

Further, two optical information recording substrates 20 (the reflective layer of one substrate is a highly reflective reflective layer such as Al, and the other is a semitransparent reflective layer) are provided on one surface of the substrate having no uneven surface. The semi-transparent reflective layer of the other substrate is overlaid and attached with an adhesive to form a laminated body having a two-layer recording surface, and another laminated body is similarly formed to form a total of two laminated bodies. Then, this laminated body 2
A medium in which the reflective layers are made to face each other and pasted with an adhesive,
Alternatively, a medium in which this laminated body and a transparent resin substrate are attached is also preferable (shown in FIG. 4). Alternatively, a medium in which this laminated body and a conventional optical information recording substrate having irregularities and a reflection layer are attached is also preferable. In these cases, the reproduction light side is the semitransparent reflection layer.

Such a form corresponds to the conventional double-sided reproduction four-layer type, three-layer type, and single-sided reproduction two-layer type.

It is also possible to form an uneven surface only on a part of the substrate, provide a recording layer on the reflective layer, and make it writable.

In the manufacturing method described with reference to FIG. 2 and FIG. 3 above, as the photocurable transfer sheet, a transfer sheet which does not take into consideration the surface smoothness as described above is used, and the surface smoothness of the substrate or the medium is used. A method for obtaining after manufacturing will be described. This is because even if the release sheet having good surface smoothness is used, the transfer sheet surface has sufficient smoothness due to the influence of the treatment during the production or the use of the release sheet having poor surface smoothness. It can be applied even when it cannot be obtained.

In FIG. 2, after obtaining the optical information recording substrate 20 (that is, the photo-curable transfer sheet 11 having cured unevenness), this surface is used to improve the smoothness of the surface opposite to the uneven surface of the substrate. An ultraviolet curable resin coating solution is applied to the above by a spin coater, screen printing or the like, and the coating film is irradiated with ultraviolet rays to be cured. The UV-curable resin coating liquid is mainly composed of a compound having a photopolymerizable functional group and a photopolymerization initiator which will be described later, and contains a surfactant such as a leveling agent and, if necessary, an organic solvent. Further, in order to improve smoothness, in addition to the surfactant such as the above leveling agent, polymers described below may be added. In addition to the above additives, it may contain a small amount of an ultraviolet absorber, an antioxidant, a dye, a processing aid, and the like. Further, depending on the case, a small amount of additives such as silica gel, calcium carbonate, and fine particles of silicone copolymer may be contained. Generally, it is preferable to use an ultraviolet-curable resin for hard coat, which has an excellent leveling property, because the surface hardness can be increased.

As the coating conditions, the viscosity of the coating liquid is 10
~ 1000 [mPas / 25 ° C], setting 1-1
It is preferable to carry out under the conditions of 00 seconds, irradiation time of 1 to 20 seconds, and film thickness of 1 to 10 μm.

The above-mentioned coating can be carried out at an appropriate stage in FIG. For example, it can be performed after sputtering metal or after forming an optical information recording medium.

In the above process, when the photocurable transfer sheet is pressed against the stamper, or two optical information recording substrates are
When the reflective layers are arranged so as to face each other and are superposed with an adhesive, it is preferable to perform pressing or superposition under reduced pressure. As a result, removal of bubbles and the like are smoothly performed.

The pressing under the reduced pressure is, for example, 2 times under the reduced pressure.
A method of passing a photocurable transfer sheet and a stamper between individual rolls, or a method of placing the stamper in a mold using a vacuum forming machine and pressing the photocurable transfer sheet to the stamper while depressurizing be able to.

Further, it is possible to perform pressing under reduced pressure by using a double vacuum chamber type device. 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 51, an upper chamber 52, a silicone rubber sheet 53, and a heater 55. In the lower chamber 51 inside the laminator, a laminated body 59 of the substrate, the photo-curable transfer sheet and the stamper or a laminated body 59 bonded with an adhesive between the substrates having irregularities is placed. Both the upper chamber 52 and the lower chamber 51 are evacuated (decompressed). The laminated body 59 is heated by the heater 55, and then the upper chamber 52 is returned to the atmospheric pressure while the lower chamber 51 is exhausted, and the laminated body is pressure-bonded. After cooling, the laminate is taken out and transferred to the next step. Thereby, degassing is sufficiently performed at the time of evacuation, and the stamper or the substrate and the photocurable transfer sheet can be pressure-bonded to each other without bubbles.

The photocurable transfer sheet of the present invention preferably comprises a photocurable composition containing a reactive polymer having a photopolymerizable functional group having a glass transition temperature of 20 ° C. or lower.

The photocurable composition is generally a reactive polymer having the above-mentioned photopolymerizable functional group, a compound (monomer or oligomer) having a photopolymerizable functional group (preferably (meth) acryloyl group), a photopolymerizable composition. It is composed of an initiator and optionally other additives.

Examples of the reactive polymer having a photopolymerizable functional group include alkyl acrylates (eg, methyl acrylate, ethyl acrylate, butyl acrylate,
2-ethylhexyl acrylate) and / or alkyl methacrylate (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate), a homopolymer or copolymer (ie, acrylic resin), and a main chain or side chains. Examples thereof include those having a photopolymerizable functional group in the chain. Such a polymer is obtained, for example, by copolymerizing one or more kinds of (meth) acrylate with (meth) acrylate having a functional group such as a hydroxyl group (eg, 2-hydroxyethyl (meth) acrylate). It can be obtained by reacting a polymer with a functional group of the polymer and a compound having a photopolymerizable group, such as an isocyanatoalkyl (meth) acrylate.

The reactive polymer of the present invention preferably contains a photopolymerizable functional group in an amount of generally 1 to 50 mol%, particularly 5 to 30 mol%. The photopolymerizable functional group is preferably an acryloyl group, a methacryloyl group, a vinyl group,
Particularly, an acryloyl group and a methacryloyl group are preferable.

The glass transition temperature of this reactive polymer is generally 20 ° C. or lower (preferably 10 ° C. or lower), and by setting the glass transition temperature to 20 ° C. or lower, the resulting photocurable transfer layer is a stamper. When pressure-bonded to the uneven surface, it is possible to have flexibility that can closely follow the uneven surface. In particular, the glass transition temperature is 15 ° C to -50 ° C.
By setting the range to, excellent followability is obtained. If the glass transition temperature is too high, a high pressure is required at the time of sticking, which leads to a reduction in workability, and if it is too low, a sufficient altitude cannot be obtained after curing.

Further, the reactive polymer of the present invention generally has a number average molecular weight of 5,000 to 1,000,000, preferably 10,000 to 300,000, and a weight average molecular weight of generally 5,000 to 1,000,000, preferably 10.
It is preferably 000 to 300,000.

Specific examples of the compound having a photopolymerizable functional group include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate.
Ethylhexyl polyethoxy (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, phenyloxyethyl (meth) acrylate, tricyclodecane mono (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate, acryloylmorpholine, N-vinylcaprolactam, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenyloxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, neopentyl glycol Dipropoxydi (meta)
Acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, trimethylolpropane tri ( (Meth) acrylate, pentaerythritol tri (meth)
(Meth) acrylate monomers such as acrylate, pentaerythritol tetra (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, and ditrimethylolpropane tetra (meth) acrylate, polyol compounds (eg, ethylene glycol,
Propylene glycol, neopentyl glycol, 1,
6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-
Butyl-1,3-propanediol, trimethylolpropane, diethylene glycol, dipropylene glycol, polypropylene glycol, 1,4-dimethylolcyclohexane, bisphenol A polyethoxydiol, polytetramethylene glycol, and other polyols,
Polyester polyols which are the reaction products of the above polyols with polybasic acids such as succinic acid, maleic acid, itaconic acid, adipic acid, hydrogenated dimer acid, phthalic acid, isophthalic acid, terephthalic acid or their acid anhydrides. A polycaprolactone polyol which is a reaction product of the polyols and ε-caprolactone, a reaction product of the polyols and the ε-caprolactone of the polybasic acid or these acid anhydrides, a polycarbonate polyol, a polymer polyol, etc. ) And an organic polyisocyanate (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 the like) and a hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 2-
Hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3
-Phenyloxypropyl (meth) acrylate, cyclohexane-1,4-dimethylol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, glycerin di (meth) acrylate, etc.), a polyurethane (meth) acrylate, Examples thereof include (meth) acrylate oligomers such as bisphenol type epoxy (meth) acrylate which is a reaction product of bisphenol type epoxy resin such as bisphenol A type epoxy resin and bisphenol F type epoxy resin and (meth) acrylic acid. These compounds having a photopolymerizable functional group can be used alone or in combination of two or more.

As the photopolymerization initiator, any known photopolymerization initiator can be used, but one having good storage stability after blending is desirable. As such a photopolymerization initiator, for example, 2-hydroxy-2-methyl-1
-Phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, acetophenone such as 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, benzoin such as benzyldimethylketal, benzophenone , Benzophenone-based compounds such as 4-phenylbenzophenone and hydroxybenzophenone, thioxanthone-based compounds such as isopropylthioxanthone and 2-4-diethylthioxanthone, and other special ones such as methylphenylglyoxylate. Particularly preferably, 2-hydroxy-2-
Methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-
(4- (methylthio) phenyl) -2-morpholinopropane-1, benzophenone and the like can be mentioned. These photopolymerization initiators may be used in any proportion of one or more known benzoic acid-based accelerators such as 4-dimethylaminobenzoic acid or known conventional photopolymerization accelerators such as tertiary amines. Can be mixed and used. Further, the photopolymerization initiator alone can be used alone or in combination of two or more kinds. A photopolymerization initiator is generally added to the photocurable composition in an amount of 0.1
It is preferable to contain -20 mass%, especially 1-10 mass%.

Of the photopolymerization initiators, examples of the acetophenone-based polymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, diethoxyacetophenone and 2-phenoxydichloroacetophenone. Hydroxy-2-methyl-
1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropane-1 -One, 4- (2-hydroxyethoxy) -phenyl (2-hydroxy-2-
Propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, and the like, benzophenone-based polymerization initiators such as benzophenone, benzoylbenzoic acid, and benzoylbenzoic acid. Acid methyl, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide,
3,3'-Dimethyl-4-methoxybenzophenone and the like can be used.

As the acetophenone-based polymerization initiator, especially 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- (4- (methylthio) phenyl ) -2-Morpholinopropane-1 is preferred. The benzophenone-based polymerization initiator is preferably benzophenone, benzoylbenzoic acid or methyl benzoylbenzoate. Further, as a tertiary amine photopolymerization accelerator, triethanolamine, methyldiethanolamine, triisopropanolamine, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate. , Ethyl 4-dimethylaminobenzoate, (n-butoxy) ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate and the like can be used. Particularly preferably, the photopolymerization accelerator is ethyl 4-dimethylaminobenzoate, 4-
Dimethylaminobenzoate (n-butoxy) ethyl, 4-
Examples include isoamyl dimethylaminobenzoate and 2-ethylhexyl 4-dimethylaminobenzoate. As described above, the components of the photopolymerization initiator are used by combining the above three components.

The photocurable transfer sheet of the present invention has a glass transition temperature of 20 ° C. or lower and a transmittance and a transmittance of 70% after curing.
It is preferable to design the photocurable composition so as to satisfy the above. Therefore, in addition to the compound having a photopolymerizable functional group and the photopolymerization initiator, it is preferable to add the following thermoplastic resin and other additives, if desired.

The mass ratio of the above-mentioned reactive polymer: compound having a photopolymerizable functional group: photopolymerization initiator is generally 4
0 to 100: 0 to 60: 0.1 to 10, especially 60 to 10
It is preferably from 0: 0 to 40: 1 to 10.

As another additive, a silane coupling agent (adhesion promoter) can be added. Examples of the silane coupling agent include 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 (Aminoethyl) -γ-aminopropyltrimethoxysilane and the like, and one of these may be used alone or two or more of them may be used in combination. The addition amount of these silane coupling agents is the above-mentioned reactive polymer 1
Usually, 0.01 to 5 parts by weight is sufficient with respect to 00 parts by weight.

Similarly, an epoxy group-containing compound can be added for the purpose of improving the adhesiveness. Examples of the epoxy group-containing compound include triglycidyl tris (2-hydroxyethyl) isocyanurate; neopentyl glycol diglycidyl ether; 1,6-hexanediol diglycidyl ether; acryl glycidyl ether;
2-ethylhexyl glycidyl ether; phenyl glycidyl ether; phenol glycidyl ether; p-
t-butylphenyl glycidyl ether; adipic acid diglycidyl ester; o-phthalic acid diglycidyl ester; glycidyl methacrylate; butyl glycidyl ether and the like. 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 0.1 to 20 with respect to 100 parts by weight of the above reactive polymer.
The weight part is sufficient, and at least one of the epoxy group-containing compounds may be added alone or in combination.

As another additive, a hydrocarbon resin may be added for the purpose of improving workability and workability such as bonding. In this case, the added hydrocarbon resin may be a natural resin type or a synthetic resin type. As the natural resin type, rosin, rosin derivative and terpene type resin are preferably used. For rosin, gum resin, tall oil resin,
Wood-based resin can be used. As the rosin derivative, those obtained by hydrogenating, heterogenizing, polymerizing, esterifying, or metallizing rosin can be used. As the terpene-based resin, a terpene-based resin such as α-pinene and β-pinene, and a terpene-phenolic resin can be used. Further, other natural resins such as dammar, cobal and shellac may be used. On the other hand, petroleum-based resins, phenol-based resins, and xylene-based resins are preferably used in the synthetic resin system. 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 alkylphenol 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.

Acrylic resins can also be added. For example, alkyl acrylate (eg, methyl acrylate, ethyl acrylate, butyl acrylate) and /
Alternatively, a homopolymer or a copolymer obtained from an alkyl methacrylate (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate) can be mentioned. Moreover, the copolymer of these monomers and another copolymerizable monomer can also be mentioned. In particular, polymethyl methacrylate (PMMA) is preferable in terms of reactivity during photocuring, durability after curing, and transparency.

The amount of the polymer such as the above-mentioned hydrocarbon resin added is appropriately selected, but is preferably 1 to 20 parts by weight, more preferably 5 to 100 parts by weight of the reactive polymer.
15 parts by weight.

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. Further, depending on the case, a small amount of additives such as silica gel, calcium carbonate, and fine particles of silicone copolymer may be contained.

A photocurable transfer sheet comprising the photocurable composition of the present invention (including types in which surface smoothness is not taken into consideration)
The above-mentioned reactive polymer, a compound having a photopolymerizable functional group (monomer and oligomer), and optionally other additives are uniformly mixed, and after kneading with an extruder, roll, etc., calender, roll, It can be used by forming a film into a predetermined shape by a film forming method such as T-die extrusion or inflation. The transfer sheet having a smooth surface of the present invention can be obtained by extruding the kneaded product from an extruder or the like as described above, casting the kneaded product into a sheet having a surface roughness Ra of 30 nm or less, and cooling. If necessary, the other surface can be covered with a sheet (release sheet).

Alternatively, each constituent component is uniformly mixed and dissolved in a good solvent, and the solution is flow-coated, roll-coated, gravure roll method, Mayer bar method, lip-die coating method on a separator precisely coated with silicone or fluororesin. It can be obtained by a method of forming a film by coating on the above support by the above method and drying the solvent. When a transfer sheet having a smooth surface according to the present invention is obtained, it can be obtained by casting the above solution on a sheet (preferably a polycarbonate sheet) having a surface roughness Ra of 30 nm or less and drying the solution.

The thickness of the photocurable transfer sheet is generally 1 to 1000 μm, preferably 5 to 500 μm, and particularly 5
˜300 μm is preferred. When the thickness is less than 1 μm, the sealing property is poor and the irregularities of the transparent resin substrate may not be completely filled.
On the other hand, if it is thicker than 1000 μm, the thickness of the recording medium increases,
There is a possibility that a problem may occur in the storage of the recording medium, assembly, etc., and there may also be a possibility that the light transmission will be affected.

As the material of the above support, a transparent organic resin having a glass transition temperature of 50 ° C. or higher is preferable, and as such a support, a polyester resin such as polyethylene terephthalate, polycyclohexylene terephthalate or polyethylene naphthalate is used. Polyamide, nylon 46, modified nylon 6T, nylon MXD6, polyamide resin such as polyphthalamide, ketone resin such as polyphenylene sulfide and polythioether sulfone, sulfone resin such as polysulfone and polyether sulfone, and polyether Transparent resin whose main component is organic resin such as nitrile, polyarylate, polyetherimide, polyamideimide, polycarbonate, polymethylmethacrylate, triacetylcellulose, polystyrene and polyvinyl chloride. It is possible to use a plate. Among these, polycarbonate, polymethylmethacrylate,
Polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in birefringence and can be preferably used.

Further, as a material for the release sheet having a surface roughness Ra of 30 nm or less, a transparent organic resin having a glass transition temperature of 50 ° C. or more is preferable. As such a support, polyethylene terephthalate or polycyclohexylene terephthalate is used. Polyester resins such as polyethylene naphthalate, nylon 46, modified nylon 6T, nylon MXD6, polyamide resins such as polyphthalamide, polyphenylene sulfide, ketone resins such as polythioether sulfone, polysulfone, polyether sulfone, etc. In addition to sulfone resins, polyether nitrile, polyarylate, polyether imide, polyamide imide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene, polyvinyl chloride The organic resin etc. can be used transparent resin substrate having a main component. Among these, polycarbonate, polymethylmethacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate are excellent in light transmittance and can be preferably used.

The photocurable transfer sheet of the present invention thus obtained comprises a photocurable composition containing a reactive polymer having a glass transition temperature of 20 ° C. or lower. It is preferable that the light transmittance in the wavelength region of up to 800 nm is 70% or more. Further, the light transmittance of the cured photocurable transfer sheet in the wavelength range of 380 to 800 nm is preferably 70% or more. That is, by setting the glass transition temperature to 20 ° C. or lower, when the photocurable transfer sheet is pressure-bonded to the uneven surface of the stamper, the photocurable transfer sheet can have the flexibility to closely follow the uneven surface. In particular, when the glass transition temperature is in the range of 15 ° C to -50 ° C, the followability is excellent. If the glass transition temperature is too high, a high pressure is required at the time of sticking, which leads to a reduction in workability, and if it is too low, a sufficient altitude cannot be obtained after curing.

The photocurable transfer sheet has a thickness of 380 to 420 nm.
The light transmittance in the wavelength region (preferably 380 to 800 nm) is 70% or more, and this is to prevent the reduction in the intensity of the read signal by the laser. 380-4
The light transmittance in the wavelength region of 20 nm is preferably 80% or more. The same applies to the cured sheet.

The reactive polymer in the photocurable composition preferably has 1 to 50 mol% of a polymerizable functional group. As a result, the obtained photocurable transfer sheet can have strength capable of retaining its shape after being cured. As described above, the photopolymerization initiator is preferably in the range of 0.1 to 10% by mass, and if it is less than this range, the curing rate is too slow and the workability is poor, and if it is too large, the transfer accuracy is lowered.

The photocurable transfer sheet according to the present invention can be provided in the form of a film whose film thickness precision is precisely controlled, so that it can be easily and accurately attached to a stamper. Further, this bonding is carried out by a simple method such as a pressure roll or a simple press at 20 to 100 ° C.
It can be cured at room temperature for 1 to several tens of seconds after being temporarily pressure-bonded with, and because the self-adhesive force peculiar to this adhesive does not cause displacement or peeling of the laminate, it can be handled freely until photo-curing. have.

In the case of curing the photocurable transfer sheet of the present invention, many light sources that emit light in the ultraviolet to visible range can be adopted, for example, ultrahigh pressure, high pressure, low pressure mercury lamps, chemical lamps, xenon lamps, halogen lamps. , Mercury halogen lamps, carbon arc lamps, incandescent lamps, laser light and the like. The irradiation time is generally several seconds to several minutes, although it cannot be generally determined depending on the type of lamp and the strength of the light source.

Further, in order to accelerate the curing, the laminated body is preliminarily made into three layers.
You may heat to 0-80 degreeC and irradiate this with an ultraviolet ray.

A metal reflective layer is formed on the uneven surface of the obtained optical information recording substrate of the present invention by vapor deposition (eg, sputtering, vacuum vapor deposition, ion plating, etc.). Examples of the metal include aluminum, gold, silver and alloys thereof. When two optical information recording substrates are used, it is necessary to use different reflective layers, and the components, film thickness, etc. are changed.

When two optical information recording substrates are used, the optical information recording substrate of the present invention and a conventional injection molded substrate are usually used.

The reflection layers of the two optical information recording substrates provided with the reflection layers are made to face each other, one side is coated with an adhesive, and the other is laminated and cured. When the adhesive is a UV curable resin, it is obtained by UV irradiation, and when the adhesive is a hot melt adhesive, it is obtained by applying under heating and cooling. The optical information recording medium of the present invention is usually manufactured continuously in a sheet shape and punched into a disk shape at the end, but may be processed in a disk shape when a treatment under reduced pressure is required. .

[0075]

The present invention will be described in more detail with reference to the following examples. [Example 1] <Preparation of photocurable transfer sheet> (Preparation of reactive polymer) Formulation I 2-Ethylhexyl methacrylate 70 parts by mass Methyl methacrylate 20 parts by mass 2-Hydroxyethyl methacrylate 10 parts by mass Benzophenone 5 parts by mass Toluene 30 parts by mass Parts Ethyl acetate 30 parts by mass While stirring gently, the mixture having the above composition is treated at 60 ° C.
Polymerization was initiated by heating to 50 ° C. and stirred at this temperature for 10 hours to obtain an acrylic resin having a hydroxyl group on the side chain. Thereafter, 5 parts by mass of Karenz MOI (2-isocyanatoethyl methacrylate; manufactured by Showa Denko KK) was added and reacted at 50 ° C. with gentle stirring to prepare a solution 1 of a reactive polymer having a photopolymerizable functional group. Got

The obtained reactive polymer had Tg of 0 ° C. and had 5 mol% of methacryloyl groups in its side chain.

Formulation II Reactive polymer solution 1 100 parts by mass Tricyclodecane diacrylate 30 parts by mass 1-hydroxycyclohexyl phenyl ketone 1 part by mass The mixture of the above compounds is uniformly dissolved and a release film (release sheet) (surface roughening) is prepared. Ra = 20 nm; Fujimori Industry Co., Ltd.
The product was applied and dried to obtain a photocurable transfer sheet (surface roughness Ra = 20 nm) having a thickness of 100 ± 2 μm.

<Fabrication of Optical Information Recording Substrate with One Reflective Layer> A photocurable transfer sheet was used in which 2 kg of a nickel rubber stamper having a concave-convex surface as a pit was used with a roller made of silicone rubber. The photocurable transfer sheet was pressed with a load to form a laminate, and the uneven shape of the stamper was transferred onto the surface of the transfer sheet.

Next, from the side of the photocurable transfer sheet, using a metal halide lamp, an integrated light amount of 2000 mJ / cm.
UV irradiation was performed under the conditions of ² to cure the transfer layer.

The stamper and the release sheet were removed from the laminate, and the silver alloy was sputtered on the uneven surface of the cured photocurable transfer sheet (optical information recording substrate) to form a semitransparent reflective layer of silver alloy. . Thus, an optical information recording substrate with a reflective layer was obtained.

<Production of Optical Information Recording Substrate with Other Reflective Layer) Polycarbonate is melted and solidified in a mold having an uneven surface as pits to give a thickness of 1100 μm.
m optical information recording substrate was molded. An Al reflective layer was formed by sputtering aluminum on the formed uneven surface. The other optical information recording substrate with a reflective layer was obtained.

<Preparation of Optical Information Recording Medium> A commercially available photocurable liquid adhesive (SD-661, Dainippon Ink and Chemicals, Inc.) was provided on one reflective layer of the two optical information recording substrates with a reflective layer obtained above. Kogyo Co., Ltd.) was applied by a spin coating method, two optical information recording substrates with a reflective layer were attached to each other with the reflective layers, and the adhesive was photocured. Thereby, an optical information recording medium (surface roughness Ra = 2 nm) was obtained.

Example 2 <Preparation of Photocurable Transfer Sheet> (Preparation of Reactive Polymer) Formulation I ′ n-hexyl methacrylate 50 parts by mass 2-hydroxyethyl methacrylate 50 parts by mass benzophenone 5 parts by mass Toluene 30 parts by mass Ethyl acetate 30 parts by mass While stirring gently, the mixture having the above composition is mixed at 60 ° C.
Polymerization was initiated by heating to 50 ° C. and stirred at this temperature for 10 hours to obtain an acrylic resin having a hydroxyl group on the side chain. Thereafter, 50 parts by mass of Karenz MOI (2-isocyanatoethyl methacrylate; Showa Denko KK) was added and reacted at 50 ° C. with gentle stirring to give a solution 2 of a reactive polymer having a photopolymerizable group. Obtained.

The obtained reacted polymer had Tg of 5 ° C. and had a methacryloyl group in the side chain of 50 mol%.

Formulation II ′ Reactive polymer solution 2 100 parts by weight 1,6-hexanediol dimethacrylate 10 parts by weight 1-hydroxycyclohexyl phenyl ketone 1 part by weight The mixture of the above formulation is uniformly dissolved to obtain Pure Ace C1.
10-70 (surface roughness Ra = 2 nm; thickness 70 μm; manufactured by Teijin Ltd.) was applied to form a photocurable transfer layer having a dry thickness of 30 ± 2 μm. This gives a thickness of 100 ± 2
A photocurable transfer sheet (surface roughness Ra = 2 nm) of μm was obtained.

The following one optical information recording substrate with a reflective layer and the other optical information recording substrate with a reflective layer, and an optical information recording medium were produced in the same manner as in Example 1, whereby a DVD (surface roughness) was prepared. Ra = 2 nm) was obtained.

[Comparative Example 1] In Example 1, a mixture of compounds for forming a photocurable transfer sheet was uniformly dissolved, and a polyester release film (release sheet) MRF-50 was prepared.
(Surface roughness Ra = 33 nm; thickness 70 μm; Teijin Ltd.)
Applied) to form a photocurable transfer layer having a dry thickness of 30 ± 2 μm. As a result, a photocurable transfer sheet (surface roughness Ra = 33 nm) having a thickness of 100 ± 2 μm was obtained.

The following one optical information recording substrate with a reflective layer and the other optical information recording substrate with a reflective layer and an optical information recording medium were produced in the same manner as in Example 1.

[Example 3] One exposed surface of the optical information recording medium obtained in Comparative Example 1 (exposed surface on the reproducing side)
Hard coating solution (SEIKA BEAM VDAL29
2. Apply Dainichi Seika Kogyo Co., Ltd. with a spin coater,
It was irradiated with ultraviolet rays and cured.

The surface roughness Ra (center line average roughness) of the sheets used in Examples 1 to 3 and Comparative Example was measured as follows.

Surface roughness measuring method: The center line average roughness (Ra) of the sheet was measured using a contact type surface roughness meter (Talystep; manufactured by Taylor Hopson Co., Ltd.).

<Evaluation of Optical Information Recording Substrate and Optical Information Recording Medium> (1) Light Transmittance (Wavelength Range of 380 to 420 nm) One photocurable transfer sheet was measured in the wavelength range of 380 to 420 nm according to JIS-K6717. The light transmittance was measured. 80% or more was ◯, and less than 80% was X.

(2) Land Roughness Roughness of the land surface of the surface where the pits are formed is
It evaluated using FM (atomic force microscope). Those that were sufficiently smooth were rated as ◯, and those that were significantly lacking in smoothness were rated as x.

(3) Signal reading The reproduced waveform of the obtained optical information recording medium is measured at a wavelength of 405 nm.
Measurement was performed by using the laser of No. 1 and the reproduced waveform obtained was compared with the waveform of the stamper used for manufacturing. The ones that matched the waveform of the stamper were marked with ◯, and those that almost did not match were marked with x.

The test results obtained are shown in Table 1.

Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Light transmittance (380-420 nm) ○ ○ ○ ○ Land surface roughness ○ ○ ○ ○ Signal reading ○ ○ ○ ×

[0097]

As is apparent from the above, the photocurable transfer sheet of the present invention can easily and accurately transfer the uneven surface of the stamper for making a substrate of an optical information recording medium by pressing, and The surface opposite to is extremely smooth. Therefore, the obtained optical information recording substrate and medium have a signal surface on which the uneven surface of the stamper is accurately transferred, and the surface on the laser light irradiation side is extremely smooth. Such an optical information recording medium has an effect that there is almost no error during recording and reproduction.

Further, since the optical information recording substrate of the present invention is formed by being deformed by softening using a photocurable transfer sheet and then cured, a good transfer can be obtained even when the substrate has a thin thickness of 300 μm or less. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an embodiment of a photocurable transfer sheet of the present invention.

FIG. 2 is a cross-sectional view showing an example of a method for manufacturing the optical information recording substrate and the laminated body of the present invention.

FIG. 3 is a cross-sectional view showing an example of a method for manufacturing the optical information recording medium of the present invention.

FIG. 4 is a cross-sectional view showing another example of the optical information recording medium of the present invention.

FIG. 5 is a schematic view for explaining a pressing method using a double vacuum chamber type device.

FIG. 6 is a cross-sectional view showing a conventional optical information recording medium.

FIG. 7 is a cross-sectional view showing a conventional optical information recording medium.

[Explanation of symbols]

11 Photo-curable Transfer Sheet 20 Photo-curable Transfer Sheet (Optical Information Recording Substrate) 12a and 12b Release Sheet 12c Support 13 Silver Alloy Reflective Layer 30 Optical Information Recording Substrate 40 Optical Information Recording Medium 21 Stamper 33 Al Reflective Layer 34 Adhesive Layers 1, 2 Transparent Resin Substrates 1a, 2a Reflective Layer 3 Adhesive Layer 1b Semi-Transparent Layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahito Inamiya             3-1-1 Ogawa Higashi-cho, Kodaira-shi, Tokyo Stock market             Company Bridgestone F-term (reference) 4J027 AA02 BA08 BA19 BA20 CB10                       CC03 CD05                 5D029 KA15 KB02 KB14 KC04 KC09                       RA07 RA08 RA45 RA46 RA49                 5D121 AA02 CA10 DD03

Claims (26)

[Claims] 1. A photocurable composition comprising a reactive polymer having a photopolymerizable functional group and deformable under pressure, and having a surface roughness Ra of at least one surface of 30.
A photo-curable transfer sheet having a thickness of nm or less. 2. The glass transition temperature of the photocurable composition is 20.
The photocurable transfer sheet according to claim 1, which has a temperature of not higher than ° C. 3. The photocurable transfer sheet according to claim 1, wherein the surface roughness Ra is 10 nm or less. 4. The photocurable transfer sheet according to claim 1, which further has a light transmittance of 70% or more in a wavelength range of 380 to 420 nm. 5. The photocurable transfer sheet according to claim 1, which further has a light transmittance of 70% or more in a wavelength range of 380 to 800 nm. 6. The reactive polymer has a photopolymerizable functional group of 1
The photocurable transfer sheet according to claim 1, wherein the photocurable transfer sheet contains ˜50 mol%. 7. The photocurable transfer sheet according to claim 6, wherein the photopolymerizable functional group is a (meth) acryloyl group. 8. The photocurable composition comprises a photopolymerization initiator of 0.1.
The photocurable transfer sheet according to claim 1, wherein the photocurable transfer sheet contains 1 to 10% by mass. 9. A thickness of 5 to 300 μm.
8. The photocurable transfer sheet according to any of 8. 10. A photocurable composition containing a reactive polymer having a photopolymerizable functional group, which is deformable by pressurization, in a molten state, on the surface of a support having a surface roughness Ra of 30 nm or less. It casts, The manufacturing method of the photocurable transfer sheet in any one of Claims 1-9 characterized by the above-mentioned. 11. A coating solution containing a reactive polymer having a photopolymerizable functional group and containing a photocurable composition that can be deformed by pressure is applied onto the surface of a support having a surface roughness Ra of 30 nm or less. It is applied to and dried on.
10. The method for producing a photocurable transfer sheet according to any one of 9 to 10. 12. The uneven surface of a stamper having unevenness on the surface as recording pits and / or grooves,
10. A laminate comprising the photocurable transfer sheet according to any one of 9 to 10 closely attached along the uneven surface. 13. An information recording substrate comprising the cured coating of the photocurable transfer sheet according to claim 1 and having unevenness as recording pits and / or grooves formed on one surface of the cured coating. An optical information recording substrate, wherein the surface roughness Ra of the surface of the cured coating opposite to the uneven surface is 30 nm or less. 14. An optical information recording substrate having unevenness as recording pits and / or grooves on the surface thereof, and a reflective layer formed on the uneven surface, and unevenness as recording pits and / or grooves at the surface. And an optical information recording substrate having a semi-transparent reflective layer formed on the uneven surface thereof, the reflective layers being opposed to each other and being bonded via an adhesive layer, at least one of The substrate according to claim 1, comprising the cured coating of the photocurable transfer sheet according to claim 1, wherein the surface roughness Ra of the surface of the cured coating opposite to the concavo-convex surface is 30 nm or less. Information recording medium. 15. An optical information recording substrate having unevenness as recording pits and / or grooves on the surface thereof, and a reflective layer formed on the uneven surface, and unevenness as recording pits and / or grooves on the surface. And an optical information recording substrate having a semi-transparent reflective layer formed on the uneven surface, and the latter semi-transparent reflective layer bonded to the surface without the reflective layer of the former via an adhesive layer. A medium, wherein at least one of the substrates comprises the cured coating of the photocurable transfer sheet according to claim 1, and the surface roughness Ra of the surface of the cured coating opposite to the concavo-convex surface is 30 nm or less. An optical information recording medium characterized by being present. 16. A cured coating of a photocurable transfer sheet comprising a photocurable composition which contains a reactive polymer having a photopolymerizable functional group and is deformable under pressure, wherein one surface of the cured coating is formed. An optical information recording substrate comprising concaves and convexes as recording pits and / or grooves, wherein a surface smoothing layer which is a cured coating of an ultraviolet curable resin coating layer is formed on the surface opposite to the concave and convex surface. An optical information recording substrate having a surface roughness Ra of 30 nm or less. 17. An optical information recording substrate having unevenness as recording pits and / or grooves on the surface thereof, and a reflecting layer formed on the uneven surface, and unevenness as recording pits and / or grooves at the surface thereof. And an optical information recording substrate having a semi-transparent reflective layer formed on the uneven surface thereof, the reflective layers being opposed to each other and being bonded via an adhesive layer, at least one of The substrate of comprises a cured coating of a photocurable transfer sheet comprising a photocurable composition that contains a reactive polymer having a photopolymerizable functional group and is deformable by pressure,
A light having a surface smoothing layer, which is a cured coating of a coating layer of an ultraviolet curable resin, provided on the surface opposite to the uneven surface of the cured coating, and the surface roughness Ra of this layer is 30 nm or less. Information recording medium. 18. An optical information recording substrate having unevenness as recording pits and / or grooves on the surface thereof, and a reflective layer formed on the uneven surface, and unevenness as recording pits and / or grooves on the surface. And an optical information recording substrate having a semi-transparent reflective layer formed on the uneven surface, and the latter semi-transparent reflective layer bonded to the surface without the reflective layer of the former via an adhesive layer. A photocurable transfer sheet, which is a medium, in which at least one of the substrates has a layer including at least an uneven surface, which comprises a photocurable composition that contains a reactive polymer having a photopolymerizable functional group and is deformable by pressure. And a surface smoothing layer, which is a cured film of a coating layer of an ultraviolet curable resin, is provided on the surface opposite to the uneven surface of the cured film, and the surface roughness R of this layer.
An optical information recording medium characterized in that a is 30 nm or less. 19. The optical information recording medium according to claim 16, which has a surface roughness Ra of 10 nm or less. 20. The glass transition temperature of the photocurable composition is 2
The optical information recording medium according to any one of claims 16 to 19, which has a temperature of 0 ° C or lower. 21. A cured coating of a photocurable transfer sheet, comprising:
21. The optical information recording medium according to claim 16, which has a light transmittance of 70% or more in a wavelength range of 0 to 420 nm. 22. The cured film of the photocurable transfer sheet, 38.
22. The optical information recording medium according to claim 16, which has a light transmittance of 70% or more in a wavelength range of 0 to 800 nm. 23. The optical information recording medium according to claim 16, wherein the reactive polymer contains 1 to 50 mol% of a photopolymerizable functional group. 24. The optical information recording medium according to claim 16, wherein the photopolymerizable functional group is a (meth) acryloyl group. 25. The optical information recording medium according to claim 16, wherein the photocurable composition contains 0.1 to 10% by mass of a photopolymerization initiator. 26. The thickness of the photocurable transfer sheet is 5 to 30.
The optical information recording medium according to any one of claims 16 to 25, which has a thickness of 0 μm.