JPH02156433A - Information recording medium and its manufacture - Google Patents

Abstract

PURPOSE:To improve precision and to enable mass production by constituting a preformative layer of a polymer thin film comprising an admixture of thermoplastic resin and photopolymerizable monomers. CONSTITUTION:A thermoplastic photopolymerizable film 12 having a protective film 13 on its back surface is adhered to the resin substrate 11 by heating and pressing with a roll 10. After removing the protective film 13, the laminated body of the resin substrate 31 and the photopolymerizable film 32 is adhered to a stamper 34 having reverse patterns on its surface by pressing and heating the film 32. Then the laminated body of the resin substrate 41 and the film 42 is exposed to UV light with irradiating the substrate 41 to cure the film 42. The laminated body of the substrate 41 and the film 42 is peeled off from the stamper 44 and the recording layer 65 is formed on the preformative layer 62. By this method, since the preformative layer is a film, it is easily handled and suitable for mass production. As the photopolymerizable film consisting of thermoplastic resin, photopolymerizable monomers and an initiator for photopolymerization is easily softened by heat, the film shows good adhesion to the stamper and the patterns are accurately transferred.

Description

Detailed Description of the Invention [Field of the Invention] The present invention relates to an information recording medium having a recording layer on which information can be written, read and/or erased on a preformat layer having pregrooves and/or prepits; The present invention relates to a manufacturing method thereof.

[Technical Background of the Invention] In recent years, information recording media that use beams with crystal energy density, such as laser beams, have been developed and put into practical use. This information recording medium is generally called an optical disk.
It can be used as a video disc, an audio disc, a large capacity still image file, and a large capacity computer disk memory. Recently, magnetic floppy disks that use laser light only for tracking servo have been considered as such information recording media.

The basic structure of an optical disk is a disc-shaped transparent substrate made of plastic, glass, etc., and a Bi
, a recording layer made of metal or semimetal such as Sn, In, Te, etc. Generally, a pre-format such as a pre-groove for tracking, a pre-pit in which format information, etc. is recorded is formed on the substrate. In addition, the surface of the substrate on which the recording layer is provided is coated with an undercoat layer or an intermediate layer made of a polymeric material in order to improve the flatness of the substrate, improve the adhesion with the recording layer, and improve the sensitivity of the optical disc. There may be layers.

An optical disk substrate (replica disk) on which a preformat such as a pregroove or a prepit is formed before the recording layer is formed is generally produced as follows.

First, a positive type photoresist layer is formed on the surface of a glass plate or the like to create a resist master.

Next, the resist layer is irradiated (exposed) with laser light while rotating the resist master disk at high speed. After the photoresist layer is irradiated with laser light, it is developed and, if desired, baked for a certain period of time to produce an optical disk master having preformats such as groups and pre-pits on its surface. Next, Ni was removed from the optical disk master.
After electroforming, a mold is made to create a stand bar.

Furthermore, using this stamper, an optical disk substrate (replica disk) is formed on which preformats such as pregrooves and prepits are formed by a molding method such as injection molding.
is created. In this case, the groups on the optical disk master also become groups on the optical disk substrate, and there is a corresponding relationship.

The optical disc can be obtained by forming a recording layer by depositing the metal or the like on the pregroove or the like of an optical disc substrate on which the pregroove or the like is formed.

Optical disk substrates on which pre-formats such as pre-grooves and pre-pits are formed before forming such a recording layer have been produced and studied using molding methods such as the above-mentioned injection molding method, embossing method or 2P method. (Japanese Unexamined Patent Publication No. 5794946, Unexamined Japanese Patent Application No. 62-1
(See Publication No. 80452). The above injection molding method and embossing method are methods in which a preformat is formed directly on the surface of a resin substrate, whereas the 2P method is different in that another resin layer is provided on the substrate and a preformat is formed there. .

That is, in the injection molding method, since pregrooves and the like are directly formed on the substrate surface, the size and grain size of the groove shape of the pregroove and the shape of the pit of the prepit are unstable and vary greatly during manufacturing. Furthermore, in the embossing method, a pregroove or the like is formed by pressing a stand bar while heating the surface of a resin substrate, so the temperature during heating must be strictly controlled, making it difficult to obtain high transfer accuracy. Therefore, both have serious problems in terms of accumulation.

In addition, in the 2P method, which provides a separate layer for formatting, UV
A preformat layer is formed by transferring a pregroove or the like from a stamper to the resist with a curable monomer layer sandwiched therebetween. In the case of this 2P method, the pregroove and the like can be transferred with relatively high accuracy. However, since liquid UV curable resin is used as the material for the UV curable layer, handling is complicated and difficult, it takes a relatively long time to obtain one molded product, and mass production is poor. There is.

The above-mentioned resin substrates include a conventional substrate obtained from a rigid resin, and a substrate using a flexible resin film, which has recently attracted attention because of its manufacturing advantages. This flexible resin film has the advantage that it is advantageous in terms of production since it is possible to perform continuous processing such as continuous application of the flexible resin film in the form of a web. When such a flexible resin film is used as a substrate, the above-mentioned method for forming pre-grooves etc. has a further disadvantage in productivity.

[Object of the invention] The present invention provides a pregroove and/or a pregroove with highly accurate dimensions.
Another object of the present invention is to provide an information recording medium in which a recording layer is formed on a pre-format layer in which pre-pits are formed.

Another object of the present invention is to provide a novel manufacturing method that can conveniently and precisely manufacture the above-mentioned high-performance information recording medium.

A further object of the present invention is to provide information recording media such as optical disks, optical cards, and magnetic floppy disks that have excellent tracking susceptibility.

[Summary of the Invention] The present invention is characterized in that a recording layer capable of writing, reading and/or erasing information is provided on a preformat layer provided on the surface of a substrate and having pregrooves and/or prepits on the surface. An information recording medium, characterized in that the preformat layer is a thin film polymer consisting of a mixture of a thermoplastic resin and a photopolymerizable polymer, advantageous for producing the information recording medium. [I] Steps 1) to 4) below; 1) Pregroove and/or
or 2) press and heat the photopolymerizable film onto the surface of a stamper having an inverted pre-format pattern consisting of pre-pits, and cure the photopolymerizable film by irradiating it with light; 3) forming a disk substrate having a preformat layer on the surface by releasing the preformat layer from the stamper; 4) writing information on the preformat layer of the disk substrate; A method for producing an information recording medium comprising forming a readable and/or erasable recording layer, and; [11] Steps 1) to 5) below; 1) A thermoplastic photopolymerizable film is coated on the surface. 2) Pressing and bonding a transparent resin substrate onto the photopolymerizable film while heating it to the surface of a stamper having an inverted preformat pattern consisting of pregrooves and/or prepits; 3) Pressure bonding the photopolymerizable film while heating it. The photopolymerizable film is turned into a preformat layer having the preformat on the surface by irradiating it with light and curing. 4) By releasing the preformat layer from the stamper, a preformat layer is formed on the surface. 5) forming a recording layer on which information can be written, read and/or erased on a preformat layer of the disk substrate;

Preferred embodiments of the information recording medium of the present invention are as follows.

1) The information recording medium, wherein the substrate is a flexible resin film.

2) An information recording medium characterized in that the preformat layer is a thin film polymer made of a mixture of a thermoplastic resin, a photopolymerizable polymer, and a photopolymerization initiator.

Preferred embodiments of the method [I] for manufacturing an information recording medium of the present invention are as follows.

1) A method for manufacturing the information recording medium, characterized in that a flexible resin film is used as the substrate.

2) The method for manufacturing the information recording medium, characterized in that the laminated layer of the thermoplastic photopolymerizable film is formed by pressing the thermoplastic photopolymerizable film while heating.

3) The method for producing the information recording medium, characterized in that the lamination of the thermoplastic photopolymerizable film is formed by applying and drying the thermoplastic photopolymerizable film-forming coating liquid.

Preferred embodiments of the method [n] for manufacturing an information recording medium of the present invention are as follows.

1) A method for manufacturing the information recording medium, characterized in that a flexible resin film is used as the substrate.

[Effects of the Invention] The information recording medium of the present invention having the above configuration has a preformat layer in which pregrooves and/or prepits with good dimensional accuracy are formed on the surface provided on the substrate, and can easily be It can be manufactured with high precision.

The preformat layer of the information recording medium of the present invention is of a type that can be cured by ultraviolet rays, or is not in a liquid form as used in the conventional 2P method, but in a film form. Therefore, the formation of pregrooves and/or prepits is performed by pressing the film against a stamper while heating it. Since the film having the composition of the present invention is extremely easily softened by heat, the formation of the prepits etc. can be performed very easily and accurately. Since the film is photocured and then peeled off from the standber to obtain the preformat layer of the present invention, the preformat layer has extremely precise dimensions and shape. Therefore, the information recording medium having the preformat layer has extremely excellent tracking accuracy.

Furthermore, since the preformat layer is in the form of a film, it is easy to handle and is suitable for mass production. In particular, when using a flexible resin film in the form of a web that can be subjected to continuous processing such as continuous coating, continuous processing and mass production can be easily performed by providing the preformat layer of the present invention. can.

Further, since the preformat layer of the present invention has excellent tracking accuracy, it can be applied to information recording media such as optical cards and magnetic floppy disks.

[Detailed Description of the Invention] The present invention provides an optical disk, an optical card, a magnetic It relates to information recording media such as floppy disks. The recording layer of the present invention may be one in which recording, reproduction and/or erasing can be performed by light, or by other methods such as a magnetic head. However, it is necessary that at least tracking during recording, reproduction, etc. can be performed by irradiating light onto the preformat layer having the preformat.

Such pre-formatted layers have traditionally been produced using injection molding methods,
It is formed by the 2P method, embossing method, etc. Both the injection molding method and the embossing method utilize the property of thermal softening of the substrate surface, and have the disadvantage that the dimensional accuracy is unstable and its variation is large during manufacturing. On the other hand, although the 2P method achieves the above-mentioned dimensional accuracy, it is complicated and difficult to handle because it uses liquid UV-curable resin as the material for forming the preformat layer, and it takes a relatively long time to obtain one molded product. It is difficult to mass produce.

The information recording medium of the present invention eliminates the above-mentioned drawbacks, has excellent dimensional granularity, has little dimensional variation during manufacturing, and is suitable for mass production. That is, the information recording medium of the present invention has a preformat layer provided on a substrate, in which pregrooves and/or prepits with good dimensions and area are formed on the surface. Such a preformat layer of the present invention is of a type that is cured by ultraviolet rays,
Instead of a liquid like that used in the 2P method, a film is used. Therefore, the formation of pre-grooves and/or pre-pits is carried out by pressing the film onto a stand bar while heating it. The film of the present invention is mainly composed of a thermoplastic resin and a photopolymerizable polymer (preferably containing a photopolymerization initiator), and is extremely easily softened by heat. Can be done accurately. After the film is photocured, it is peeled off from the stand bar to obtain the preformat layer of the present invention. The preformatted layer thus obtained has extremely high precision in size and shape. Furthermore, since the preformat layer is in the form of a film, it is easy to handle and suitable for mass production. In particular, when using a flexible resin film in the form of a web that can be subjected to continuous processing such as continuous coating, continuous processing and mass production can be easily performed by providing the preformat layer of the present invention. can.

The method of manufacturing the above-mentioned information recording medium of the present invention will be explained in detail with reference to FIGS. 1 to 6, which show typical embodiments.

FIG. 1 shows a resin substrate 11, a thermoplastic photopolymerizable film 12 with a protective film 13 adhered to the back side that is laminated on the front surface, and a thermoplastic photopolymerizable film 12 that is laminated onto the resin substrate 11 while being heated. It is composed of rolls 10 to be crimped (laminated).

In FIG. 1, a thermoplastic photopolymerizable film 12 having a protective film 13 on the back surface is pressure-bonded (laminated) onto the front surface of a resin substrate 11 while being heated by a roll 10. As shown in FIG. The temperature during the above-mentioned pressure bonding is preferably in the range of room temperature to 200°C, the pressure is preferably in the range of 0.1 to 50 kg/co+2, and the film feeding speed is in the range of 0.05 to 50 m/min. Further, in order to improve the adhesion between the resin substrate 11 and the thermoplastic photopolymerizable film 12, it is preferable to provide an adhesive layer (eg, styrene-butadiene copolymer) on the surface of the resin substrate. Further, in the case of the laminate, another protective sheet may be closely attached to the surface of the thermoplastic photopolymerizable film 12 that comes into contact with the substrate. This is peeled off before or during lamination of the photopolymerizable film 12.

FIG. 2 shows a structure in which a resin substrate 21, a thermoplastic photopolymerizable film 12, and a protective film 13 are laminated in this order.

In FIG. 2, the protective film 13 of the photopolymerizable film 12 has been peeled off, leaving the laminate of the resin substrate 11 and the thermoplastic photopolymerizable film 12. This is generally done at room temperature.

FIG. 3 shows a laminate of a resin substrate 31 and a thermoplastic photopolymerizable film 32, a stubber 34 having an inverted preformat pattern consisting of pregrooves and prepits on the surface, and a thermoplastic photopolymerizable film on the stubber 34. Roll 3 for crimping 32 while heating (laminate)
Consists of 0.

In FIG. 3, a laminate of a resin substrate 31 and a thermoplastic photopolymerizable film 32 is placed on a roll 30 facing the film 32 on a stand bar 34 having an inverted pre-format pattern consisting of pre-grooves and pre-pits on the surface. It is crimped (laminated) while heating using a . The temperature during the above crimping is in the range of room temperature to 200℃, and the pressure is 0.1
~50kg/Cl112, film feed speed is 0.0
A range of 5 to 50 m/min is preferred. The thermoplastic photopolymerizable film 32 is made of a thermoplastic resin, a photopolymerizable monomer, and a photoinitiator, and is easily softened by heat, so that it can adhere extremely well to the uneven portions of the stamper. , pre-pits, etc. can be transferred very easily and accurately.

FIG. 4 shows a stamper 44 comprising a laminate of a resin substrate 41 and a thermoplastic photopolymerizable film 42, and a stamper 44 having an inverted pattern of a preformat consisting of pregrooves and prepits on the surface to which the laminate is pressed. .

Here, UV exposure is performed from the substrate side on the laminate that is in very good contact with the uneven portion of the stamper, and it is shown that the thermoplastic photopolymerizable film 42 changes to a hardened state (preformat layer). .

FIG. 5 is composed of a laminate of a resin substrate 51 and a preformat layer 52 made of a hardened thermoplastic photopolymerizable film, and a stamper 54 to which the laminate is pressed.

Here, the state in which the above-mentioned laminate, on which the uneven portion of the stamper has been extremely accurately transferred, is peeled off from the stamper is shown.

In FIG. 6, a resin substrate 61, a preformat layer 62, and a recording layer 65 are laminated. That is, the recording layer 65 is placed on the preformat layer 62 of the laminate obtained in FIG.
is provided.

In this way, the information recording medium of the present invention can be manufactured. The above description merely shows one embodiment of the present invention, and is not limited thereto. That is, the present invention is characterized in that a thermoplastic photopolymerizable film is pressure-bonded while heating to a stamper having an inverted pattern of a preformat made of pregrooves or the like on its surface, and then photocured. Therefore, in the crimping shown in Fig. 3, first only the thermoplastic photopolymerizable film is crimped onto the stamper, then the substrate is crimped onto the photopolymerizable film, and the rest is the same as the process shown in Fig. 4 and thereafter. The manufacturing method of the present invention also includes the case where a step consisting of the following steps is adopted. moreover,
For example, in FIGS. 1 and 2, a thermoplastic photopolymerizable film is laminated onto a resin substrate without pressure bonding the thermoplastic photopolymerizable film-forming coating solution (thermoplastic resin, It can also be carried out by applying and drying a photopolymerizable monomer, a photopolymerization initiator, and a solvent. Further, in the photocuring of the photopolymerizable film, by using a transparent stamper, light irradiation can be performed from the stamper side, so in this case, the substrate does not need to be transparent.

Since the preformat layer of the present invention is in the form of a film, it is easy to handle and suitable for mass production. especially,
When a flexible resin film in the form of a web and capable of continuous processing such as continuous coating is used for the substrate, continuous processing and mass production can be easily performed by providing the preformat layer of the present invention.

Furthermore, since the preformat layer of the present invention has excellent tracking accuracy, it can be applied to information recording media such as optical cards, magnetic floppy disks, and magnetic cards.

As for the resin substrate, recording layer, undercoat layer, etc. constituting the information recording medium of the present invention, any known ones can be used, and these will be briefly explained below.

Materials for the resin substrate used in the present invention include acrylic resin, vinyl chloride resin, polystyrene resin,
Examples include thermoplastic resins such as polyamide resins, polyolefin resins (eg, polypropylene, polyethylene), polycarbonates, cellulose acetate resins, polyester resins (eg, polyethylene terephthalate), and polyvinylidene chloride. Preferred are polyolefin resins, polycarbonates, and cellulose acetate resins. The resin substrate may be a rigid substrate or a flexible resin film. A flexible resin film is preferable in order to obtain the effect of excellent production efficiency by the production method of the present invention. The thickness of the flexible resin film substrate is preferably within the range of 20 to 200 μm.

An undercoat layer (and/or intermediate layer) may be provided on the surface of the substrate on which the recording layer is provided, for the purpose of improving flatness, improving adhesive strength, and preventing deterioration of the recording layer. Examples of materials for the undercoat layer (and/or intermediate layer) include polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, nitrocellulose, polyethylene, chlorinated polyolefin, polypropylene, polystyrene, styrene/butadiene copolymer, Polymer substances such as polycarbonate; UV-curable resins such as acrylic yarns; organic substances such as silane coupling agents; and inorganic oxides (Si02, /M!.

0, etc.) and inorganic substances such as inorganic fluoride (MgF2). Using the above materials, for example, a layer made of UV curable resin may be provided as an undercoat layer, and an inorganic oxide layer may be further provided thereon as an intermediate layer, or the above materials may be combined to form a single layer. More than one layer can be provided as appropriate.

In the present invention, a thermoplastic photopolymerizable film is laminated on the substrate surface to form a preformat layer having pregrooves and/or prepits. and,
The above thermoplastic photopolymerizable film is laminated by pressing the thermoplastic photopolymerizable film while heating, or by applying and drying a coating solution for forming the thermoplastic photopolymerizable film. It is preferable that The thermoplastic photopolymerizable film may be a commercially available product, or
For example, after applying the coating liquid onto a film and drying it, the dried film may be transferred and pressure-bonded to a substrate while peeling off the film.

The thermoplastic photopolymerizable film is made of at least a thermoplastic resin and a photopolymerizable polymer (preferably containing a photopolymerization initiator). A photoinitiator is generally required when curing with ultraviolet light.

Examples of thermoplastic resins include polymethyl methacrylate, acrylic acid/(meth)acrylic acid alkyl ester copolymer, polyacrylic acid, (meth)acrylic acid alkyl ester/acrylonitrile copolymer, vinylidene chloride/acrylonitrile copolymer, Vinyl chloride copolymer, ABS resin, nitrocellulose, polyethylene, chlorinated polyolefin, polypropylene, polystyrene,
Examples include styrene/butadiene copolymer and styrene/maleic anhydride copolymer.

Examples of photopolymerizable molecules include poly(meth)acrylates of polyhydric alcohols such as monoesters, diesters, triesters, and tetraesters of acrylic acid;
Examples include oligomers such as acrylamides, allyl compounds, styrene compounds, and urethane acrylates.

The photopolymerization initiator may be any compound that can initiate polymerization with light, such as J.

Examples include carbonyl compounds, organic sulfur compounds, peroxides, reddix compounds, azo and diazo compounds, halogen compounds, photoreducible dyes, etc., as described in Chapter 5 of Light Sensitive Systems J by Kosar. can.

In addition to the above, thermal polymerization inhibitors, plasticizers, organic solvents, etc. may be added as desired.

In the present invention, the recording layer formed on the information recording medium is of a type (write-once type or D RAW [Direct Read
After Write type) and a type that can perform recording and erasing repeatedly using magneto-optical recording or phase change (erasable type, i.e. E-D RA).
W [Erasable-Direct Read
There is a ``hefter deceased'' type).

Examples of materials used for the DRAW type recording layer include T.
e, Zn% I n, Sn, Zr, All, Ti, Cu
, Ge, Au, Pt, etc.; semimetals such as Bi, As, Sb; semiconductors such as Si; and alloys thereof, or combinations thereof. Compounds such as sulfides, oxides, borides, silicon compounds, carbides, and nitrides of these metals, semimetals, or semiconductors; and mixtures of these compounds and metals can also be used in the recording layer. The recording layer may further contain various known metals, semimetals, or compounds thereof as recording layer materials.

Alternatively, the recording layer may be made of a dye such as a cyanine dye (combined with a polymer binder if desired).

The recording layer may be a single layer or a multilayer, and the thickness of the recording layer is generally from 100 to 50 mm in terms of optical properties required for optical information recording.
It is in the range of 500 or more, preferably 150 to 1 ooo
z range.

Further, in the case of an E-DRAW in which the recording layer utilizes phase change, a recording layer made of the following material, which is a substance that undergoes a phase change due to temperature, is provided. At this time, a light-absorbing substance may be dispersed and contained if necessary.

Examples of the phase change include a change between a crystalline state and an amorphous state, a change between a compatible state and a phase-separated state, and the like.

An example of a substance that causes a state change between a crystalline state and an amorphous state is S b too-x T e x (30<
x <60), 5b2Se, Te01 (0<x<2)
, As-Te-Ge-based, 5n-Te-Se-based, and other metal and semimetal compounds. In addition, known metals, semimetals, and compounds thereof that undergo a state change between a crystalline state and an amorphous state can be used. Further, a typical example of a material capable of magneto-optical recording is an amorphous perpendicularly magnetized film made of a transition metal and a rare earth element. Examples of transition metals include Fe, Co, etc., and rare earth elements include Tb, Gd, Nb, etc.

Furthermore, a typical example of a substance that undergoes a state change between a compatible state and a phase separated state is a polymer blend consisting of a mixture of two or more types of polymers. However, a combination of a polymer and a monomer may exhibit similar behavior, and such a composition is also included in the polymer blend in the present invention.

If the recording layer is made of a metal or the like, or if the substance that can cause a phase change is an inorganic substance such as the metal,
It can be formed on the substrate by vapor deposition, sputtering, or ion blasting on the substrate surface. The recording layer may be a single layer or a multilayer, but its layer thickness is generally 100 to 15 mm in terms of optical density required for optical information recording.
It is in the range of 00 or more, preferably in the range of 150 to 1000λ.

In addition, when the recording layer is an organic compound such as a dye or the above-mentioned polymer blend, a coating solution is prepared by dissolving the substance and, if necessary, a light-absorbing substance in an appropriate solvent, and this coating solution is coated with a spin code method. It can be formed on a substrate by applying it to the surface of the substrate by a coating method such as a roll coating method and then drying it.

Further, if desired, an adhesion layer made of a silane curing agent or the like may be provided in order to improve the adhesion between the recording layer and the protective layer.

On the recording layer, on the tracking guide layer, or between the recording layer and the tracking guide layer, inorganic substances such as 5i02, MgF, 5n02, UV curable resin, etc. are used to physically and chemically protect the recording layer. A protective layer made of an organic substance may also be provided.

In addition, in order to improve the scratch resistance, moisture resistance, and prevention of deformation and deterioration of the recording layer on the substrate side or the surface opposite to the substrate, inorganic substances such as silicon dioxide, tin oxide, and magnesium fluoride may be used. A thin film may be provided.

In addition, on the surface of the recording layer on the substrate side or on the opposite side to the substrate, a light beam made of metals such as An, Cr, and Ni is coated for the purpose of improving the S/N ratio during information reproduction and improving the sensitivity during recording. A reflective layer may also be provided.

Next, examples of the present invention will be described.

C Example 1 A coating solution for forming a thermoplastic photopolymerizable film having the following composition was applied on a web-like polyethylene terephthalate (PET) protective film with a thickness of 25 μm using a web coater, and dried to form a layer. A layer (film) with a thickness of 10 μm was formed.

Plastic weight 4 Film coating Polymethyl methacrylate 1500 parts (average molecular weight: 140000) Tetraethylene glycol diacrylate 610 parts Trimethylolpropane triacrylate 240 parts p-Toluenesulfolamide 162 parts p-
Methoxyphenol 1 part 4.4'-bis(diethylamino) Benzophenone 4 parts Benzophenone 15 parts Phenyltribromomethylsulfone 37 parts Carbothioic acid amide compound 0.55 parts (the above parts are parts by weight) 50 μm thick substrate Layer thickness 0.5 μm on web-shaped polyethylene terephthalate (PET) film
After forming an undercoat layer made of a styrene-butadiene copolymer by coating and drying, a layer of a 10 μm thermoplastic photopolymerizable film was laminated on the obtained protective film on the undercoat layer, Temperature 105℃ using pressure lamination
, a pressure of 2 g/cm 2 and a film feed rate of 1 m/sec (see Figure 1).

The 25 μm PET protective film was peeled off at room temperature from a web-like laminate in which the obtained PET substrate, the thermoplastic photopolymerizable film layer, and the 25 μm PET protective film were laminated in this order. (See Figure 2).

The above laminate was stamped with a stamper (
A layer of thermoplastic photopolymerizable film (300 μm thick) was placed facing each other and bonded by pressure lamination (see FIG. 3).

The irradiation energy was 100 millijoules/cm using an ultra-high pressure mercury lamp from the substrate side of the laminate crimped onto the stamper.
The preformat was formed into a thermoplastic photopolymerizable film and a cured web-like laminate was obtained by irradiating light until the temperature reached 2 (see FIG. 4).

Next, the obtained photopolymerized film (preformat layer)
A web-like laminate consisting of a substrate and a stamper is
It was peeled off at 5°C (see Figure 5).

On the preformat layer of the obtained laminate, S b soT e so was codeposited by vacuum evaporation to a layer thickness of 100 mm.
A recording layer of 0λ was formed (see FIG. 6).

The obtained web-like laminate provided with the recording layer was
．． An optical disc was punched into a 5-inch disc shape.

[Example 2] In Example 1, as a PET film serving as a substrate,
Using a 75 μm film instead of 50 μm thick,
Glow discharge treatment was performed on the film surface without applying an undercoat layer. And Example 1, without pressure laminating the photopolymerizable film onto the substrate in Example 1! A preformat layer was provided by applying the thermoplastic photopolymerizable film coating liquid used in 1 to the substrate as it was and drying it. An optical disc was manufactured in the same manner as in Example 1, from the subsequent step of press-bonding it to the stamper.

[Evaluation of optical disc] 1) A disc evaluation device (Nakamichi Disk evaluation device 0MS-1) was applied to the recording layer of the obtained information recording medium.
000) was used to evaluate the tracking servo performance by rotating at 900 r, p, m. The disks obtained in Examples 1 and 2 both exhibited good tracking servo performance.

2) In order to confirm the shape of the pregroove and prepit formed in the photopolymerized film (preformat layer) on the substrate before the recording layer of the obtained optical disc was provided, a telecomparator was used in this part. The observed image was photographed, and judgments were made based on the photograph.

From the obtained photographs, it was observed that the shapes of the pregroove and the SM portion and VFO portion of the prepit were well resolved. That is, clear images of groups and pits of 1 μm or less were obtained.

Therefore, although the information recording media obtained in Examples 1 and 2 according to the present invention can be manufactured by an extremely simple method, the tracking servo It can be said that the information recording medium has good properties.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a process of press-bonding a thermoplastic photopolymerizable film to a resin substrate. FIG. 2 is a schematic diagram showing the process of peeling a protective film from a thermoplastic photopolymerizable film. FIG. 3 is a schematic diagram showing a process of press-bonding a laminate of a resin substrate and a thermoplastic photopolymerizable film to a stamper. FIG. 4 is a schematic diagram showing the process of forming a preformat layer by irradiating a thermoplastic photopolymerizable film with ultraviolet rays. FIG. 5 is a schematic diagram showing a process in which a laminate of a resin substrate and a preformat layer is peeled off from a stamper. FIG. 6 is a schematic diagram showing a state in which a recording layer is laminated on a resin substrate and a preformat layer. be. Roll: 10,30 Resin substrate: 11,21,31,41,51° Thermoplastic photopolymerizable film: 12,22° 32.42 Protective film: 13 Stamper: 34,44.54 Preformat layer: 52° Recording layer = 65 Patent applicant Fuji Photo Film Co., Ltd. Representative Patent attorney Yasushi Yanagawa MaleM1 Figure IUV exposure Figure 2 Figure 3

Claims (1)

[Claims] 1. A recording layer capable of writing, reading, and/or erasing information is provided on a preformat layer provided on the surface of a resin substrate and having pregrooves and/or prepits on the surface. An information recording medium, characterized in that the preformat layer is a thin film polymer made of a mixture of a thermoplastic resin and a photopolymerizable monomer. 2. Steps 1) to 4) below: 1) Pregroove and/or pregroove on the surface of the resin substrate laminated with the thermoplastic photopolymerizable film.
or 2) press and heat the photopolymerizable film onto the surface of a stamper having an inverted pre-format pattern consisting of pre-pits, and cure the photopolymerizable film by irradiating it with light; 3) forming a disk substrate having a preformat layer on the surface by releasing the preformat layer from the stamper; 4) writing information on the preformat layer of the disk substrate; A method for manufacturing an information recording medium, which comprises forming a readable and/or erasable recording layer. 3. Steps 1) to 5) below: 1) Pressing a thermoplastic photopolymerizable film onto the surface of a stamper having an inverted preformat pattern consisting of pregrooves and/or prepits on the surface while heating. 2) Pressing a resin substrate onto the photopolymerizable film while heating 3) Curing the photopolymerizable film by irradiating it with light to convert the photopolymerizable film into a plate having the preformat on the surface. 4) forming a disk substrate having a preformat layer on the surface by releasing the preformat layer from the stamper; 5) writing, reading and/or information on the preformat layer of the disk substrate; A method of manufacturing an information recording medium comprising forming an erasable recording layer.