JP2011175685A - Method and apparatus for manufacturing multilayer information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer information recording medium in which a signal can be transferred to a UV curing resin a plurality of times on the same signal transfer substrate having enough light resistance to UV light irradiation and flexibility at which physical damage is not hardly generated when the substrate is separated from the UV curing resin by using a the signal transfer substrate, and to provide an apparatus for manufacturing the multilayer recording medium. <P>SOLUTION: The method at least includes: a step of laminating the UV curing resin that is applied on a base with an information signal surface of the transfer substrate so that the UV curing resin and the surface face; and a step of curing the UV curing resin by irradiating the UV curing resin with a UV ray from a UV ray transmission table on which the signal transfer substrate is installed; and a step of separating an interface of the UV curing resin from an interface of the signal transfer substrate where the signal transfer substrate is composed of organic and inorganic hybrid materials. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an information recording medium for reproduction or recording / reproduction, particularly a multilayer information recording medium having a plurality of information recording layers, and a manufacturing apparatus therefor.

  In recent years, with the expansion of the amount of information required for information equipment, audiovisual equipment, etc., attention has been focused on information recording media such as optical disks, which are excellent in data access, storage of large volumes of data, and downsizing of equipment. Therefore, the recording information has been densified. For example, as a means for increasing the density of an optical disk, a single layer is 25 GB using an optical head in which the wavelength of the laser light is about 400 nm and the numerical aperture (NA) of the condenser lens for narrowing the laser light is 0.85. An optical recording medium having a capacity of about 50 GB with two layers has been proposed (see, for example, Patent Document 1).

  The structure and manufacturing method of the conventional multilayer information recording medium described in Patent Document 1 will be described below with reference to FIGS.

  FIG. 5 shows a cross-sectional view of a conventional multilayer information recording medium. This multilayer information recording medium is arranged on the first signal substrate 601 on which pits and guide groove signal portions having a concavo-convex shape are transferred and formed on one side, and on the surface provided with the concavo-convex shape of the first signal substrate 601. A second signal substrate 603 in which a signal portion of a pit or guide groove having a concavo-convex shape is transferred and formed on a surface opposite to a bonding surface between the first thin film layer 602 and the first thin film layer 602; It is comprised by the 2nd thin film layer 604 arrange | positioned on the surface in which the uneven | corrugated shape was provided, and the transparent layer 605 formed so that the 2nd thin film layer 604 might be covered.

  The first signal substrate 601 is manufactured by using a resin material such as polycarbonate or polyolefin and transferring and forming pits and guide grooves in a concavo-convex shape on one side by injection compression molding or the like. The thickness of the first signal board 601 is about 1.1 mm. Each of the first thin film layer 602 and the second thin film layer 604 includes a recording film and a reflective film, and on the surface (signal surface) side of the first signal substrate 601 and the second signal substrate 603 where the signal portion is formed, It is produced by a method such as sputtering or vapor deposition. Examples of the material of the reflective film mainly include metal materials such as silver alloy and aluminum, and a material capable of obtaining an efficient reflectivity with respect to laser light having a wavelength of about 400 nm is employed. There are two types of recording film materials, a rewritable type and a write-once type. For the rewritable type, a material capable of recording and erasing data a plurality of times is used, and a recording material such as GeSbTe or AgInSbTe is used. The write-once type uses a material that can be recorded only once and changes irreversibly. TeOPd is a typical material.

  The second signal substrate 603 is formed by a spin coating method using an ultraviolet curable resin, and the concavo-convex shape (signal portion) of pits and guide grooves is transferred and formed by the signal transfer substrate. The signal transfer substrate used here is a substrate in which concave and convex shapes such as pits and guide grooves are formed on one side like the first signal substrate 601. Specifically, the signal transfer substrate is a substrate provided with a signal surface having a concavo-convex shape corresponding to a signal portion formed on the second signal substrate 603 as a transfer surface. The second signal substrate 603 is bonded to such a signal transfer substrate through an ultraviolet curable resin so that its signal surface faces the first signal substrate 601. After the ultraviolet curable resin is cured, the signal transfer substrate is bonded to the ultraviolet curable resin. It is formed by peeling from the interface. The transparent layer 605 is made of a material that is transparent (highly transmissive) to recording / reproducing light, and has a thickness of about 0.1 mm. As the material, an adhesive such as a photo-curing resin or a pressure-sensitive adhesive can be used. For example, an ultraviolet curable resin can be formed on the second thin film layer 604 by spin coating. Recording and reproduction of the multilayer information recording medium thus manufactured is performed by making a recording / reproducing laser beam enter from the transparent layer 605 side.

  6 (A) to 6 (G) are cross-sectional views showing respective steps in a conventional multilayer information recording medium manufacturing method, and the conventional multilayer information recording medium manufacturing method will be described using these.

  First, a first thin film layer 702 including a recording film and a reflective film is formed on the signal surface of the first signal substrate 701 on which pits and guide grooves are formed by a method such as sputtering or vapor deposition. The first signal substrate 701 is a surface opposite to the surface on which the first thin film layer 702 is formed, and is fixed on the rotary table 703 by means such as vacuum (see FIG. 6A).

  On the first thin film layer 702 formed on the first signal substrate 701 fixed to the turntable 703, an ultraviolet curable resin 704 is formed with a desired radius by a dispenser to form a second signal substrate which is a resin layer. It is applied concentrically on the top (see FIG. 6B).

  Next, the ultraviolet curable resin 704 is stretched by spinning the rotary table 703 (see FIG. 6C). Excess resin and bubbles can be removed from the ultraviolet curable resin 704 by centrifugal force acting on the ultraviolet curable resin 704 during the stretching. At this time, the thickness of the UV curable resin 704 to be stretched is arbitrarily set to the viscosity of the UV curable resin 704, the spin rotation speed, the time, and the surrounding atmosphere (temperature, humidity, etc.) in which the spin rotation is performed. Thus, the desired thickness can be controlled.

  On the stretched ultraviolet curable resin 704, a signal transfer substrate made of a material such as polycarbonate or polyolefin in which pits and guide grooves are formed in an uneven shape on one surface (signal surface) like the first signal substrate 701. 705 is overlaid so that the signal surfaces of both the first signal substrate 701 and the signal transfer substrate 705 are opposed to each other (see FIG. 6D). At this time, in order to prevent air bubbles from being mixed between the signal transfer substrate 705 and the ultraviolet curable resin 704, it is preferable that this superposition process is performed in a vacuum atmosphere.

  Next, although not shown in the drawings, the unevenness of the signal transfer substrate is reliably transferred to the resin by lightly applying pressure to the signal transfer substrate 705. Here, in order to prevent the thickness of the ultraviolet curable resin from being varied due to the pressurization, the pressurization is performed by pressurizing a flat plate member disposed on the signal transfer substrate 705.

  After removing the plate-like member that prevents the irradiation of ultraviolet rays from the signal transfer substrate, the first signal substrate 701, the first thin film layer 702, the ultraviolet curable resin 704, and the signal transfer substrate 705 are integrated into a multilayer structure 706. Then, ultraviolet rays are irradiated from the signal transfer substrate 705 side by the ultraviolet irradiator 707 to cure the ultraviolet curable resin 704 sandwiched between the two signal surfaces (see FIG. 6E). The ultraviolet rays are irradiated from the signal transfer substrate 705 side because the materials such as polycarbonate and polyolefin used for the signal transfer substrate 705 transmit ultraviolet rays to the ultraviolet curable resin 704 by transmitting ultraviolet rays to some extent. This is because it can be reached.

  After the ultraviolet curable resin 704 is cured, the signal transfer substrate 705 is peeled off at the interface with the ultraviolet curable resin 704, thereby forming the second signal substrate 710 on which the signal surface is transferred (FIG. 6F). )reference).

  A second thin film layer 708 including a recording film and a reflective film is formed on the signal surface of the second signal substrate 710 by a method such as sputtering or vapor deposition. Finally, a transparent layer 709 that is almost transparent to recording / reproducing light (having a high transmittance) is formed by, for example, spin coating of an ultraviolet curable resin, stretching, and curing by ultraviolet irradiation (see FIG. 6G). ).

  As described above, in the conventional method of manufacturing a multilayer information recording medium, when producing the second signal substrate on which the signal portion is transferred and formed, the ultraviolet curable resin is irradiated with ultraviolet rays through the signal transfer substrate, and the ultraviolet curing is performed. In order to cure the resin, it was important to use a signal transfer substrate made of a material having a sufficiently high ultraviolet transmittance (for example, polycarbonate or polyolefin).

Further, a metal material may be used as the signal transfer substrate. For example, a signal transfer substrate formed of nickel on a signal transfer substrate, a multilayer structure in which a first signal substrate, a first thin film layer, and an ultraviolet curable resin are integrated, is formed on a nickel signal transfer substrate on an ultraviolet curable resin and nickel. Are superimposed so that they face each other. The ultraviolet curable resin of the bonded structure is irradiated with ultraviolet rays through the first signal substrate and the first thin film layer to be cured. However, since the first signal substrate and the first thin film layer must transmit ultraviolet rays, there is a concern that the degree of freedom in designing the first thin film layer is reduced.
Japanese Patent No. 3763763 JP 2003-85839 A JP-A-9-265684

  The signal transfer substrate as described above used for manufacturing an information recording medium is desired to be repeatedly used in view of manufacturing cost and productivity. However, since materials such as polycarbonate and polyolefin used for the signal transfer substrate absorb ultraviolet rays and deteriorate, the ultraviolet transmittance of the signal transfer substrate is reduced by repeated use. Once again it was impossible to use.

  In addition, when quartz glass having light resistance to ultraviolet rays is used as an alternative material to prevent a decrease in the ultraviolet transmittance of the signal transfer substrate due to ultraviolet irradiation, when peeling the signal transfer substrate from the ultraviolet curable resin, There was a problem that the quartz glass was cracked or chipped. This also raises a problem that the manufacturing cost of the multilayer information recording medium increases.

  Further, when a metal material such as Ni is used for the signal transfer substrate, the signal transfer substrate does not transmit ultraviolet rays, and therefore it is necessary to irradiate ultraviolet rays from the signal substrate side opposite to the signal transfer substrate. Specifically, it is necessary to dispose a metallic transfer substrate on a table, dispose an ultraviolet curable resin and a signal substrate thereon, and perform ultraviolet irradiation from the signal substrate side. However, in adopting this process, it is necessary for the signal substrate to have ultraviolet translucency. However, if a thin film layer is already formed on the signal substrate, the ultraviolet rays that reach the ultraviolet curable resin are used. The amount was reduced, and there was a problem that the curing of the intermediate layer was hindered. If a resinous signal transfer substrate made of a material such as polycarbonate or polyolefin is placed on the table instead of the metallic transfer substrate, it takes time to replace these signal transfer substrates that cannot be used repeatedly. This has the disadvantage of causing an increase in tact time.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for forming an intermediate layer of a multilayer information recording medium that makes it possible to use a signal transfer substrate a plurality of times and that does not cause physical damage to the signal transfer substrate.

  In order to achieve the above object, a method for producing a multilayer information recording medium of the present invention includes at least a step of bonding an ultraviolet curable resin applied on a substrate and an information signal surface of a transfer substrate so as to face each other, It includes a step of irradiating the ultraviolet curable resin with ultraviolet rays from the side of the ultraviolet transmissive table on which the signal transfer substrate is installed and curing, and a step of peeling from the interface between the ultraviolet curable resin and the signal transfer substrate. The signal transfer substrate is formed of an organic-inorganic hybrid material. In this specification, the organic / inorganic hybrid material is an organic / inorganic composite material containing an organic component and an inorganic component, and has a structure in which the organic portion and the inorganic portion are dispersed almost uniformly at the molecular level. I mean. In addition, the multilayer information recording medium manufactured by the manufacturing method of the present invention may be an information recording medium provided with at least two layers of the first information recording layer and the second information recording layer as information recording layers. An information recording medium including three or more information recording layers is also included.

  The multilayer information recording medium manufacturing apparatus of the present invention includes at least a signal transfer substrate that transmits ultraviolet light, an ultraviolet transmission table for installing the transfer substrate, and a signal transfer substrate surface of the ultraviolet transmission table opposite to the signal transfer substrate surface. And a means for pressurizing the inner periphery of the substrate from the ultraviolet transmitting table side or pulling up the inner periphery of the substrate to the side opposite to the ultraviolet transmitting table.

  According to the method for producing a multilayer information recording medium of the present invention, it is possible to satisfactorily carry out the transfer of the concavo-convex shape (signal part) to the ultraviolet curable resin by the signal transfer substrate and the separation of the signal transfer substrate from the resin. The transfer substrate can be used a plurality of times repeatedly. This eliminates the need to dispose of the signal transfer substrate as in the prior art, thereby reducing the material cost required for producing one signal surface. In addition, since it is not necessary to produce a plurality of signal transfer substrates for each signal surface, it is possible to realize a multilayer information recording medium manufacturing apparatus at a low cost. Furthermore, it is possible to suppress the production variation of the signal surface that occurs for each signal transfer substrate.

  According to the multilayer information recording medium manufacturing apparatus of the present invention, it is possible to realize a manufacturing apparatus that can satisfactorily perform the transfer of the signal portion to the resin and the separation from the resin and that can be used repeatedly multiple times. . Thereby, the cost required when forming one signal surface can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the following description is an example of this invention and this invention is not limited by these.

(Embodiment 1)
The method for producing a multilayer information recording medium of the present invention is provided at least between the first information recording layer, the second information recording layer, and the first information recording layer and the second information recording layer. A multilayer information recording medium including the formed resin layer. In the process of forming the resin layer,
(I) applying a liquid resin on the first information recording layer;
(II) A signal transfer substrate having a signal surface on which a signal portion having a concavo-convex shape is formed is bonded to the resin applied on the first information recording layer so that the signal surface faces the resin. Combining the steps,
(III) curing the resin in a state where the signal transfer substrate is bonded to the resin;
(IV) peeling the signal transfer substrate from the resin;
It is included. This signal transfer substrate is made of an organic-inorganic hybrid material.

  First, the organic-inorganic hybrid material used as the signal transfer substrate in the present invention will be described in detail.

  Examples of the organic-inorganic hybrid material used for the signal transfer substrate include a molecular-size inorganic part having a polyhedral structure composed of —Si—O— bonds and an organic segment in which a plurality of inorganic parts are cross-linked with each other. Materials. In the present specification, the molecular size is a size in which one side of the polyhedral structure is in the range of 0.1 to 20 nm, for example, in the range of 0.5 to 1.0 nm. Examples of the molecular size inorganic part having a polyhedral structure composed of —Si—O— bonds include octasilsesquioxane and dodecasilsesquioxane compounds. A signal transfer substrate formed of such an organic-inorganic hybrid material can be used repeatedly because the transmittance is not easily deteriorated by ultraviolet irradiation. For this reason, the manufacturing cost of a multilayer information recording medium can be reduced. In addition, since such an organic-inorganic hybrid material has appropriate flexibility, when the signal transfer substrate is peeled from the cured resin, the signal transfer substrate is hardly damaged.

  As the organic-inorganic hybrid material, it is also possible to use a cured product obtained by a hydrosilylation reaction, which does not contain a polar group that interacts with a functional group contained in a resin used for producing a resin layer of a multilayer information recording medium. it can. For example, when an acrylic resin is considered as an ultraviolet curable resin used for the resin layer, the cured product obtained by the hydrosilylation reaction is polar such as —OH, carbonyl, ether, etc. that interacts with a polar group such as carbonyl contained in the acrylic resin. The group is not included in the system. For this reason, since it can suppress that both adhere firmly by the interaction of a signal transfer board | substrate and a resin layer, it can peel from a resin layer (resin after hardening), without damaging a signal transfer board | substrate.

  The organic-inorganic hybrid material may be, for example, a cured silicon resin obtained by curing a silicon resin composition containing a silsesquioxane compound. Since the silicon resin composition containing a silsesquioxane compound can be easily cured by polymerization, a signal transfer substrate of an organic-inorganic hybrid material can be easily produced.

  As the resin used for producing the resin layer, for example, an ultraviolet curable resin can be used. In this case, the curing of the resin in the step (III) is performed by irradiating the resin with ultraviolet rays through the signal transfer substrate. As described above, when the resin layer is formed using the ultraviolet curable resin, the resin can be cured and the concavo-convex shape can be transferred in a short time, so that the cycle time of the process can be reduced and the efficiency can be improved. By using an ultraviolet curable resin that cures in a specific wavelength range, the resin can be positively cured, which facilitates the design of the manufacturing apparatus. Considering that an ultraviolet curable resin is used for the production of the resin layer, the transmittance of the signal transfer substrate with respect to light in the wavelength range of 250 nm to 280 nm is preferably 10% or more, more preferably 20% or more. preferable. By setting the light transmittance of the signal transfer substrate in the above wavelength range to such a range, curing of the ultraviolet curable resin can be promoted in a short time.

<Signal transfer substrate and manufacturing method thereof>
Next, the configuration of the signal transfer substrate of the present invention and the manufacturing method thereof will be described.

  The signal transfer substrate of the present invention is a signal transfer substrate for transferring a signal portion having a concavo-convex shape, includes a signal surface on which the signal portion is formed, and is formed of an organic-inorganic hybrid material. As the organic-inorganic hybrid material, the same material as the signal transfer substrate used in the above-described method for producing a multilayer information recording medium can be used. For example, a specific example in which the organic-inorganic hybrid material is a silicon resin cured product obtained by curing a silicon resin composition containing a silsesquioxane compound will be described below.

  As the silsesquioxane compound, for example, one containing at least one selected from the group consisting of a cage silsesquioxane compound and a partial polymer thereof represented by the following formulas (1) to (3) is used. it can.

(AR ¹ R ² SiOSiO _1.5 ) _n (R ³ R ⁴ HSiOSiO _1.5 ) _p (BR ⁵ R ⁶ SiOSiO _1.5 ) _q (HOSiO _1.5 ) _m- npq (1)
(AR ¹ R ² SiOSiO _1.5 ) _r (B ₁ R ⁵ R ⁶ SiOSiO _1.5 ) _s (HOSiO _1.5 ) tr _-s (2)
(R ³ R ⁴ HSiOSiO _1.5 ) _r (B ₁ R ⁵ R ⁶ SiOSiO _1.5 ) _s (HOSiO _1.5 ) tr _-s (3)
However, in the formulas (1) to (3), A represents a group having a carbon-carbon unsaturated bond, B represents a substituted or unsubstituted saturated alkyl group or hydroxyl group, and B ₁ represents substituted or unsubstituted. It represents an unsubstituted saturated alkyl group, a hydroxyl group or a hydrogen atom, and R ^{1 to} R ⁶ each independently represents one type of functional group selected from a lower alkyl group, a phenyl group and a lower arylalkyl group. In the formulas (1) to (3), m and t are numbers selected from 6, 8, 10, and 12, n is an integer of 1 to m-1, p is an integer of 1 to mn, and q is An integer of 0 to mnp, r represents an integer of 2 to t, and s represents an integer of 0 to tr. A signal transfer substrate made of such a material is less likely to cause a decrease in light transmittance due to light irradiation, and has good releasability from a cured resin (particularly, an ultraviolet curable resin). Furthermore, by using such a material, a signal transfer substrate having the above characteristics can be easily realized.

  In the silsesquioxane compound, at least one selected from the group consisting of a cage silsesquioxane compound and a partial polymer thereof represented by the formula (2), and the formula (3) A silsesquioxane compound containing at least one selected from the group consisting of a cage silsesquioxane compound and a partial polymer thereof is preferably used. This is because a signal transfer substrate having better characteristics can be obtained.

  The silicon resin composition may further contain at least one compound selected from the following formula (4) and the following formula (5).

^{HR 7 R 8 Si-X-} SiHR 9 R 10 ... (4)
_{H 2 C = CH-Y-} CH = CH 2 ... (5)
However, in Formula (4), X represents a bivalent functional group or an oxygen atom, and R ^{7 to} R ¹⁰ each independently represents an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. In formula (5), Y represents a divalent organic group. In such a silicon resin composition, since the compounds represented by the formulas (4) and (5) function as a crosslinking agent, a three-dimensional crosslinked structure is effectively formed in the silicon resin composition, and the cured product is The amount of residues remaining unreacted can be reduced, and as a result, the UV irradiation resistance is further improved. In order to realize a better curing reaction, at least one selected from the group consisting of a cage silsesquioxane compound represented by formula (2) and a partial polymer thereof, and represented by formula (4) Or at least one selected from the group consisting of a cage silsesquioxane compound represented by the formula (3) and a partial polymer thereof, and a formula (5) It is preferable to use a silicon resin composition containing the represented compound.

  When the group having a carbon-carbon unsaturated bond represented by A in Formula (1) and / or (2) is a chain hydrocarbon group having a carbon-carbon unsaturated bond at the terminal, excellent reactivity Therefore, a better curing reaction can be realized.

  The silsesquioxane compound of the present embodiment is, for example, a cage type silsesquioxane compound represented by the above formulas (1) to (3) and a cage type formed by partial addition reaction of these compounds. It contains at least one selected from the group consisting of partially polymerized silsesquioxane compounds (hereinafter referred to as cage-type silsesquioxane compounds of formulas (1) to (3), etc.). In addition, the silsesquioxane compound of this Embodiment may be comprised only from the cage-type silsesquioxane compound of Formula (1)-(3).

Specific examples of the silsesquioxane compound represented by the formula (1) include, for example, tetrakis (cyclohexenylethyldimethylsiloxy) -tetrakis (dimethylsiloxy) silsesquioxane (TCHS: Tetrakis) represented by the structural formula (1). (cyclohexenylethyldimethylsiloxy) -tetrakis (dimethyl-iloxy) silsesquioxane). This compound is a compound in which m = 8, n = 4, p = 4, q = 0, R ¹ , R ² , R ³ and R ⁴ are methyl groups and A is a cyclohexene group in the formula (1). . Note that structural formula (1) shows two silsesquioxane compounds, and for the sake of convenience, AR ¹ R ² Si— and R ³ R ⁴ HSiO— are simply abbreviated as R. .

  Specific examples of the silsesquioxane compound represented by the formula (2) include, for example, tetraallyldimethylsiloxy-tetratrimethylsiloxysilsesquioxane, octavinyldimethylsiloxysilsesquioxane, hexaallyldimethylsiloxy-dihydroxy. Examples include silsesquioxane.

  Specific examples of the silsesquioxane compound represented by the formula (3) include octahydridosilsesquioxane, tetratrimethyl-tetrakisdimethylsiloxysilsesquioxane, and the like.

  Moreover, in the silicon resin composition in this Embodiment, the compound represented by above-described Formula (4) and / or Formula (5) may further be contained as a crosslinking agent.

  Specific examples of the compound represented by the formula (4) include, for example, tetramethyldisiloxane. Specific examples of the compound represented by the formula (5) include divinyltetramethyldisiloxane, diallyltetramethyldisiloxane, divinyldiphenyldimethyldisiloxane, and the like.

  2A and 2B are schematic views of a three-dimensional crosslinked structure of a cured silicon resin formed by addition polymerization of cage-type silsesquioxane compounds such as TCHS. . FIG. 2A is a schematic view showing a three-dimensional crosslinked structure of a cured silicon resin formed by crosslinking a plurality of cage silsesquioxane compounds. FIG. 2B is a schematic diagram illustrating an example of the structure of a cage silsesquioxane compound. In FIG. 2A, reference numeral 201 denotes a molecular size inorganic part which is a substantially hexahedral structure formed of silicon atoms and oxygen atoms, that is, a polyhedral structure formed of —Si—O bonds. In FIG. 2A, reference numeral 202 denotes an organic segment in which a substantially hexahedral structure 201 is cross-linked. The silicon resin composition of the present embodiment is, for example, a silicon resin cured product by forming a cross-linked structure as shown in FIG.

  As shown in FIG. 2B, the silsesquioxane compound has a polyhedral (substantially hexahedral) structure formed of silicon atoms and oxygen atoms, and one side thereof is nano-level (for example, 0.5 nm). It is. From this, the silicon resin comprised from the above silsesquioxane compounds is also called nano resin.

  Such a cage silsesquioxane compound has a hydrosilane group bonded to a silicon atom via a siloxane bond or a group having a carbon-carbon unsaturated bond bonded to a silicon atom via a siloxane bond. The hydrosilane group of the cage-type silsesquioxane compound and the group having the carbon-carbon unsaturated bond of the other cage-type silsesquioxane compound are cross-linked by addition polymerization through a hydrosilylation reaction to form a silicon resin Can be obtained. At this time, a three-dimensional crosslinked structure in which the nano-sized cage structure (inorganic part) of the silsesquioxane compound is connected by the organic segment is formed. The silicon resin cured product formed in this manner has a glass-like function and has a characteristic that it is hardly deteriorated even when used in a state of being irradiated with light in a blue / near ultraviolet region. The signal transfer substrate 105 made of such a material suppresses deterioration in transmittance due to light irradiation in the blue / near ultraviolet region, and is transparent to light in such a wavelength region (high transmittance). Rate (for example, 50% or more).

  As described above, the signal transfer substrate according to the present embodiment is formed of an organic-inorganic hybrid material having a three-dimensional cross-linked structure in which the nano-sized cage structure of the silsesquioxane compound is connected by the organic segment. Therefore, it is flexible against the warpage of the substrate itself that occurs when it is peeled off from the cured UV curable resin, and is physically damaged (cracked or chipped) compared to a transfer substrate made of quartz or the like. It is hard to produce.

  By using a signal transfer substrate made of a cured silicon resin that is an organic-inorganic hybrid material as described above, it is possible to easily transfer and form good irregularities such as guide grooves and signal pits on the resin layer.

  Next, the difference in light transmittance of the signal transfer substrate due to the difference in material will be described. FIG. 3A and FIG. 3B show the light transmittance when the wavelength is changed for each signal transfer substrate made of different materials.

  From a cured silicon resin obtained by curing the silicon resin composition containing the silsesquioxane compound used in the present embodiment (hereinafter, sometimes referred to as a cured silicon resin in the present embodiment). In order to clarify the superiority of the light transmission characteristics of the signal transfer substrate, the change in light transmittance when the signal transfer substrate made of polycarbonate and polyolefin, which are commonly used materials, is irradiated with light is used as a comparative control. This is shown in FIG. The change in light transmittance of the signal transfer substrate made of the cured silicon resin in the present embodiment is shown in the graph of FIG. The thickness of the signal transfer substrate used for the light transmittance measurement is (0.6 mm). Polycarbonate (AD5503 manufactured by Teijin Chemicals) and polyolefin (ZEONOR 1430R1 manufactured by Nippon Zeon) are used in this embodiment. The cured silicone resin is obtained by crosslinking (tetrakis (cyclohexenylethyldimethylsiloxy) -tetrakis (dimethylsiloxy) silsesquioxane (TCHS) as shown below. A substrate formed of a cured body was used.

  In addition, as the light irradiation device used for the light transmittance measurement, a flash type that outputs predetermined energy was used in order to suppress thermal alteration and deformation of the signal transfer substrate as much as possible. The light intensity was set to such an intensity that the ultraviolet curable resin could be cured by irradiating the ultraviolet curable resin having a thickness of 25 nm five times with an ultraviolet flash through a polycarbonate signal transfer substrate. In addition, in order to confirm the change in transmittance with respect to the integrated irradiation amount of ultraviolet rays for each signal transfer substrate material, two types of graphs are shown, that is, the case where no ultraviolet rays are irradiated and the case where 500 times of ultraviolet flashing is performed. A self-recording spectrophotometer (MPC-3100) manufactured by Shimadzu Corporation was used for measuring the light transmittance characteristics of each signal transfer substrate material shown in the graph.

  As apparent from FIGS. 3A and 3B, the signal transfer substrate made of the cured silicon resin in the present embodiment has a wavelength of 250 to 280 nm as compared with the signal transfer substrate made of polycarbonate or polyolefin. The transmittance is large in the range. This characteristic indicates that the ultraviolet light transmission efficiency is high. Therefore, when the signal transfer substrate made of the cured silicon resin in the present embodiment is used, it is possible to cure the ultraviolet curable resin with less ultraviolet irradiation energy, which can greatly contribute to the ultraviolet irradiation efficiency and the shortening of the process cycle time. Recognize. In addition, after 500 times of ultraviolet flashing, the signal transfer substrate made of the cured silicon resin in the present embodiment has a reduced transmittance in the ultraviolet region compared to the signal transfer substrate made of polycarbonate or polyolefin. Good transmittance is obtained. From this characteristic, it can be seen that the signal transfer substrate made of the cured silicon resin in the present embodiment can maintain the ultraviolet transmittance substantially unchanged from the initial state when the ultraviolet rays are not irradiated, and the ultraviolet curable resin is cured in the ultraviolet irradiation process. It can be seen that it is not necessary to change the irradiation amount of the ultraviolet rays for irradiation. Further, when polycarbonate or polyolefin is used as the signal transfer substrate, the ultraviolet ray flash is required 5 times for curing the ultraviolet curable resin, whereas the signal transfer substrate made of the cured silicon resin in the present embodiment is used. In this case, since the light transmittance in the wavelength range of 250 to 280 nm is 10% or more, the ultraviolet curable resin can be cured in three or less ultraviolet flashes.

In the above light transmittance measurement, only the signal transfer substrate is irradiated with ultraviolet rays and the ultraviolet transmittance is measured. Actually, polycarbonate is used as the material of the signal transfer substrate, and the signal to the ultraviolet curable resin is measured. When the surface is transferred, the number of times that the signal surface can be satisfactorily transferred and formed is 20 at most. As the reason why peeling becomes difficult, in addition to the decrease in ultraviolet transmittance due to ultraviolet irradiation, in polycarbonate, as shown in FIG. 4, —C—O— (ether bond) or C═O (carbonyl bond) is present in the molecule. It is assumed that this group has a highly polar group, and this group interacts with a highly polar group such as an ether of an ultraviolet curable resin (for example, an acrylic resin) to increase the adhesion to the ultraviolet curable resin. This is because that. Further, when glass (SiO ₂ ) was used as the material for the signal transfer substrate, the adhesiveness to the ultraviolet curable resin was high, and the transfer limit of the stable signal surface was up to 20 times. The reason for this is that the glass material contains highly polar groups such as silanol (—SiOH), and these polar groups are hydrogen bonded to polar groups such as carbonyl of an ultraviolet curable resin (for example, acrylic resin). This is because it is assumed that the power will increase. In addition, when a glass material is used for the material of the signal transfer substrate, the signal transfer substrate is cracked or chipped by repeating the signal transfer due to the hard and brittle characteristics of the glass material and the high adhesion to the ultraviolet curable resin. Is likely to occur.

  On the other hand, when the signal transfer substrate made of the cured silicon resin in the present embodiment is used, the peelability from the ultraviolet curable resin is good, and there is no problem even if the transfer is repeated 100 times or more. I was able to confirm. The silicon resin cured product used for the signal transfer substrate of the present embodiment is a cured product obtained by subjecting a silsesquioxane compound to a hydrosilylation reaction. Therefore, this silicon resin cured product does not contain a highly polar group (polar group) such as —OH, carbonyl, or ether in the system, and does not cause interaction with the ultraviolet curable resin (for example, acrylic resin). Thereby, favorable peelability from the ultraviolet curable resin can be realized.

<Method for producing multilayer information recording medium>
In the embodiments described below, a multi-layer information recording medium having an optical disk shape will be described as an example. However, the present invention is not limited to the shape of an optical disk, and may be a general multi-layer information recording medium such as an optical memory card. Applicable.

  1 (A) to 1 (G) are cross-sectional views showing the steps of the method for manufacturing a multilayer information recording medium in Embodiment 1 of the present invention. The manufacturing method of the multilayer information recording medium in the present embodiment will be described with reference to these drawings.

  In order to improve the warp and rigidity of the disk, the first signal board 101 used as the base used in the method for manufacturing the multilayer information recording medium of the present embodiment is further adapted to a CD (Compact Disk) or DVD (Digital Versatile Disk). In order to have thickness compatibility with an optical disc such as), a disk having a hole having a thickness of approximately 1.1 mm and a diameter of 15 mm in the center is formed. The first signal substrate 101 has a surface (signal surface) on which a signal portion having a concavo-convex shape of pits and guide grooves is formed. A first thin film layer (first information recording layer) 102 including a recording film and a reflective film is formed on the signal surface of the first signal substrate 101 by a method such as sputtering or vapor deposition. The first signal board 101 includes a disc centering jig (not shown) provided in the approximate center of the rotary table 103 so that the amount of eccentricity with respect to the rotary axis of the rotary table 103 is small on the rotary table 103, and the rotary table. A plurality of small vacuum holes (not shown) provided on the upper surface of 103 are attracted and fixed to the rotary table 103 (see FIG. 1A).

  On the first thin film layer 102 on the first signal substrate 101 fixed by suction, an ultraviolet curable resin 104 is applied in a substantially concentric manner on a desired radius by a dispenser (see FIG. 1B).

  Next, the ultraviolet curable resin 104 is stretched by spinning the rotary table 103 (see FIG. 1C). Excess resin and bubbles can be removed from the ultraviolet curable resin 104 by centrifugal force acting on the ultraviolet curable resin 104 during stretching. At this time, the thickness of the UV curable resin 104 to be stretched can arbitrarily set the viscosity of the UV curable resin 104, the rotation speed of the spin rotation, the time, and the surrounding atmosphere (temperature, humidity, etc.) in which the spin rotation is performed. Thus, the desired thickness can be controlled.

  The stretched ultraviolet curable resin 104 has a signal transfer substrate 105 having a signal surface in which pits and guide grooves are formed in an uneven shape (signal part) on one side like the first signal substrate 101. And the signal transfer substrate 105 are overlapped so that the signal surfaces face each other (see FIG. 1D). At this time, in order to prevent air bubbles from being mixed between the signal transfer substrate 105 and the ultraviolet curable resin 104, it is preferable that the atmosphere in which the superposition is performed is a vacuum atmosphere. Although not shown, it is preferable that the ultraviolet curable resin has a certain degree of viscosity in order to invert the uncured ultraviolet curable resin 104 to face the signal transfer substrate 105. Alternatively, after the step shown in FIG. 1 (C), the ultraviolet curable resin is irradiated with ultraviolet rays for a certain period of time, and the resin is temporarily cured and then opposed to the signal transfer substrate. Leakage can be prevented.

  The signal transfer substrate 105 used here is formed of the organic-inorganic hybrid material described above. The configuration in which the signal transfer substrate is arranged on the table and the signal substrate is opposed from the top is difficult because the tact time is conventionally increased, but unlike the conventional resin signal transfer substrate, the organic-inorganic hybrid material is It has the characteristic that there is little decrease in transmittance due to ultraviolet irradiation. Therefore, it is not necessary to replace the signal transfer substrate every time, and this configuration can be adopted.

  Next, the multilayer structure 106 in which the first signal substrate 101, the first thin film layer 102, the ultraviolet curable resin 104, and the signal transfer substrate 10 are integrated is irradiated with ultraviolet rays from the signal transfer substrate 105 side by an ultraviolet irradiator 107. The ultraviolet curable resin 104 sandwiched between the two signal surfaces is cured (see FIG. 1E). At this time, the signal transfer substrate 105 is set on the ultraviolet transmission table 105A. This is because it is possible to easily correct the flatness and eccentricity when the signal transfer substrate 105 is installed in order to easily replace the signal transfer substrate 105. Further, when the organic / inorganic hybrid material is composed of only the organic / inorganic hybrid material without using the ultraviolet transmission table, the signal of both the first signal substrate 101 and the signal transfer substrate 105 is obtained because the organic / inorganic hybrid material has flexibility as described above. This is not appropriate because the signal transfer substrate 105 is warped when the surfaces are overlapped so as to face each other.

  Here, the fixing of the signal transfer substrate 105 to the ultraviolet transmission table 105A is not performed by applying an adhesive between the signal transfer substrate 105 and the ultraviolet transmission table 105A. The edges of the inner and outer peripheral parts are fixed so as to be in close contact with the ultraviolet transmitting table 105A. This is because when the signal transfer substrate 105 and the ultraviolet light transmitting table 105A are fixed by applying an adhesive, the adhesive deteriorates and the ultraviolet light is prevented from being transmitted by irradiating the ultraviolet light. The material of the fixing members 105B and 105C may be any material as long as it can withstand the force applied when the cured UV curable resin is peeled from the signal transfer substrate, and is not limited to a specific substance.

  In addition, a method of fixing the signal transfer substrate by vacuum as in the case where the first signal substrate 701 is fixed to the rotary table 703 in FIG. 6A is also conceivable, but in this embodiment in which ultraviolet rays are irradiated from the signal transfer substrate side. In this case, a vacuum suction hole or the like hinders ultraviolet light transmission. Further, when irradiating ultraviolet rays in a vacuum atmosphere, it is difficult to attract and fix the signal transfer substrate. On the other hand, by fixing the signal transfer substrate 105 and the ultraviolet transmissive table on both sides, there is no mechanism or adhesive interfering between the ultraviolet irradiator 107 and the ultraviolet curable resin, which will be described later, and the efficiency. It is possible to cure the resin well.

  Further, the fixing member bonded to the edge portion prevents the ultraviolet curable resin 104 applied on the substrate from overlapping. This is because it does not interfere with the irradiation of the ultraviolet curable resin 104 with ultraviolet rays through the ultraviolet transmissive table 105A and the signal transfer substrate 105 in a later step. Specifically, the outer peripheral end of the fixing member 105B is preferably located at a diameter of 20 mm or less, which is the inner peripheral portion of the ultraviolet curable resin. Further, the inner peripheral end of the fixing member is positioned at least on the outer peripheral side from the center hole of the disk, and when the first signal substrate 101 is peeled off from the signal transfer substrate 105 by the push-up member as will be described later, the push-up member It is necessary to be located on the outer peripheral side.

  In this embodiment, quartz is used as the table material. By using quartz, it is possible to ensure translucency and good flatness as a base.

  The ultraviolet irradiator 107 is installed so as to uniformly irradiate the ultraviolet curable resin 104 with ultraviolet rays through the ultraviolet transmission table 105A and the signal transfer substrate 105. In addition, since the signal transfer substrate 105 in this embodiment uses the above-described organic-inorganic hybrid material, it can transmit ultraviolet rays and allow sufficient ultraviolet rays to reach the ultraviolet curable resin 104. Thereby, the concave and convex shapes of pits and guide grooves provided on the signal surface of the signal transfer substrate 105 can be efficiently transferred and formed on the ultraviolet curable resin 104. In this embodiment, in order to efficiently transfer the uneven shape formed on the signal surface of the signal transfer substrate 105 to the ultraviolet curable resin 104, the viscosity of the ultraviolet curable resin 104 is set to 50 to 4000 mPa · s, for example. For example, 105 is a disk having a diameter of 120 mm, a thickness of 0.6 mm, and a center hole having a diameter of 17 mm in the center.

  After the ultraviolet curable resin 104 is cured, the signal transfer substrate 105 is peeled off at the interface with the ultraviolet curable resin 104, whereby a second signal substrate (resin layer) 110 having a signal surface is formed (FIG. 1). (See (F)). Since the signal transfer substrate 105 is formed of an organic-inorganic hybrid material, it has good peelability from the cured UV curable resin 104 and can be easily peeled off at the interface between the signal transfer substrate 105 and the UV curable resin 104. Is possible.

  For example, the first signal substrate 101 is pressed from the side of the signal transfer substrate 105 to the laminated multilayer structure 106, and a pressing means with a diameter of 15 mm <d <17 mm, for example, the tip to be raised is conical. It has a shape and is made of a metal such as stainless steel or aluminum. The pressurizing unit pressurizes only the inner peripheral portion of the first signal substrate 101 to warp the inside of the first signal substrate 101, and the ultraviolet curable resin 104 formed on the first signal substrate 101 and the signal transfer substrate 105. It can be peeled from the interface. In the above, the method of pressurizing and pushing up the first signal board 101 has been described, but the same curing can be obtained by using a configuration in which the inner periphery of the first signal board 101 is sucked or mechanically lifted in the peeling direction. Can do.

  On the signal surface of the second signal substrate 110, for example, a second thin film layer 108 including a phase change recording film and a reflective film is formed by a method such as sputtering or vapor deposition. The second thin film layer 108 can include, for example, at least one of a reflective film such as an Ag alloy, a dielectric film such as AlN, and a recording film such as TeOPd. Finally, the transparent layer 109 is formed. The transparent layer 109 can be formed by applying an ultraviolet curable resin on the second thin film layer 108, stretching the ultraviolet curable resin by spin rotation, and then irradiating and curing the ultraviolet ray. The transparent layer 109 is almost transparent to recording / reproducing light (having a high transmittance for recording / reproducing light) and has a thickness of about 0.1 mm.

  According to the present embodiment, it has sufficient light resistance to a plurality of times of ultraviolet irradiation, and also has a flexibility that does not cause physical damage when the signal transfer substrate is peeled from the ultraviolet curable resin. Since the signal transfer substrate can be realized, it is possible to realize a method for manufacturing a multilayer information recording medium in which the signal transfer substrate can be reused. For this reason, it is possible to avoid the production of the signal transfer substrate that is required every time the signal surface is transferred and formed, and it is possible to reduce the cost when the signal surface is transferred and formed. In addition, the multilayer information recording medium manufacturing apparatus can be simplified and the cost can be reduced, and the production variation of the signal portion having the uneven shape generated for each signal transfer substrate can be suppressed.

  Further, the method for producing a multilayer information recording medium of the present application enables the signal transfer substrate to be pressed and irradiated with ultraviolet rays at the same place. As described in the conventional example, a resin signal transfer substrate made of polycarbonate or the like is placed on the upper part of the ultraviolet curable resin and lightly pressed on the signal transfer substrate, both the ultraviolet irradiation lamp and the pressing mechanism are signaled. It was necessary to arrange the transfer substrate above the transfer substrate. For this reason, the step of pressing the signal transfer substrate and the step of irradiating ultraviolet rays cannot be performed at the same place. After pressing the signal transfer substrate, the signal transfer substrate and the signal substrate are integrated with each other under the ultraviolet irradiation lamp. It was necessary to transfer it to a temperature and cure it. However, in the recording medium production method of the present application, the ultraviolet irradiation lamp is disposed on the lower side of the signal transfer substrate and the signal substrate, and the mechanism for pressing the signal transfer substrate is disposed on the opposite side of the transfer substrate and the ultraviolet transmission table. Therefore, after the signal transfer substrate is pressed, the signal substrate can be cured without being transferred to another location.

  In the present embodiment, an example using a signal transfer substrate made of a cured silicon resin obtained by curing a silicon resin composition containing a silsesquioxane compound has been described. Even if it is a material, the signal transfer board | substrate which has the same characteristic is realizable.

  A multilayer information recording medium manufacturing method, a signal transfer substrate, and a manufacturing method thereof according to the present invention include all information system devices that store information, such as a computer, an optical disk player, an optical disk recorder, a car navigation system, an editing system, and a data server. It can be used to manufacture media such as AV components, memory cards, and magnetic recording media.

Sectional drawing which shows each process in the manufacturing method of the multilayer information recording medium in Embodiment 1 of this invention (A) Schematic diagram showing a three-dimensional cross-linked structure of a cured silicon resin used in Embodiment 1 of the present invention (B) A cage silsesquif constituting the cured silicone resin used in Embodiment 1 of the present invention Schematic diagram showing an example of the structure of an oxan compound Graph of change in light transmittance of signal transfer substrate by ultraviolet irradiation in Embodiment 1 of the present invention Molecular structure of polycarbonate Sectional view of a conventional multilayer information recording medium Sectional drawing which shows each process in the manufacturing method of the conventional multilayer information recording medium

Explanation of symbols

101,701 First signal substrate 102,702 First thin film layer (first information recording layer)
103, 703 Rotary table 104, 704 UV curable resin 105, 705 Signal transfer substrate 105A UV transmission table 106, 706 Multilayer structure 107, 707 UV irradiator 108, 708 Second thin film layer (second information recording layer)
109,709 Transparent layer 110,710 Second signal board (resin layer)
201 Substantially hexahedral structure (inorganic part)
202 Organic segment 601 First signal substrate 602 First thin film layer 603 Second signal substrate 604 Second thin film layer 605 Transparent layer

Claims (12)

A method of forming an intermediate layer of a recording medium with an ultraviolet curable resin, at least,
Applying an ultraviolet curable resin on the substrate;
Bonding the ultraviolet curable resin applied on the substrate and the information signal surface of the signal transfer substrate so as to face each other;
Irradiating the ultraviolet curable resin with ultraviolet rays from the ultraviolet transmitting table side on which the signal transfer substrate is installed, and curing the ultraviolet curable resin;
Peeling from the interface between the ultraviolet curable resin and the signal transfer substrate,
A method for producing a multilayer information recording medium, wherein the signal transfer substrate is formed of an organic-inorganic hybrid material. The organic-inorganic hybrid material includes a molecular-size inorganic part having a polyhedral structure composed of —Si—O— bonds, and an organic segment that crosslinks the plurality of inorganic parts. A method for producing a multilayer information recording medium as described in 1. above. 3. The method for producing a multilayer information recording medium according to claim 1, wherein the ultraviolet transmitting table is made of quartz. The step of peeling from the interface between the ultraviolet curable resin and the signal transfer substrate includes:
Fixing the signal transfer substrate to the ultraviolet transmitting table by vacuum suction;
A step of peeling the inner periphery of the substrate while curving the surface opposite to the surface on which the ultraviolet curable resin is formed;
The method for producing a multilayer information recording medium according to claim 1, comprising: The signal transfer substrate and the ultraviolet transmission table are fixed by a fixing member,
The method for manufacturing a multilayer information recording medium according to claim 1, wherein the fixing member is disposed on at least one of an inner peripheral side and an outer peripheral side of the signal transfer substrate. After the step of applying an ultraviolet curable resin on the substrate,
The method for producing a multilayer information recording medium according to claim 1, further comprising a step of temporarily curing the ultraviolet curable resin. After the step of bonding the ultraviolet curable resin and the information signal surface of the signal transfer substrate to face each other,
The method for producing a multilayer information recording medium according to claim 1, further comprising a step of pressing the signal transfer substrate toward the ultraviolet curable resin side. An apparatus for forming an intermediate layer of a recording medium with an ultraviolet curable resin, at least,
A signal transfer substrate that transmits ultraviolet light;
An ultraviolet transmission table for installing a signal transfer substrate;
UV irradiation means installed on the opposite side of the signal transfer substrate surface of the UV transmitting table;
Means for pressurizing the inner periphery of the substrate from the ultraviolet transmitting table side, or pulling up the inner periphery of the substrate to the opposite side of the ultraviolet transmitting table;
An apparatus for producing a multilayer information recording medium, comprising: The organic-inorganic hybrid material includes a molecular-size inorganic part having a polyhedral structure composed of -Si-O- bonds, and an organic segment that crosslinks the plurality of inorganic parts to each other. The manufacturing apparatus of the multilayer information recording medium as described. 10. The apparatus for manufacturing a multilayer information recording medium according to claim 8, wherein the ultraviolet transmitting table is made of quartz. The signal transfer substrate is fixed to the ultraviolet transmission table at both edges of the inner periphery or inner periphery of the signal transfer substrate, and the edges are on the substrate to be bonded to the signal transfer substrate. The apparatus for producing a multilayer information recording medium according to claim 8, wherein an application region of the ultraviolet curable resin is not included. A pressurizing means for pressing the signal transfer substrate downward;
9. The apparatus for producing a multilayer information recording medium according to claim 8, wherein the pressurizing unit is disposed on the side facing the signal transfer substrate with the ultraviolet irradiation unit and the ultraviolet transmission table interposed therebetween. .

Images