JP2005152751A - Method for forming protective layer and method for manufacturing optical information medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a protective layer or a hard coat layer which has excellent antifouling property and lubrication property of various kinds of material surface and to provide a method for manufacturing an optical information medium which has excellent antifouling property and lubrication property of recording and/or reproducing beam incident side surface and also has excellent resistance to scuffing and wear. <P>SOLUTION: The method for forming the protective layer on an object material comprises an applying process of applying a composition for protective layer consisting of active energy ray reactive silicone compound and/or fluorine compound (A) and active energy ray-curable compound (B) on an objective material 7 on which the protective layer is to be imparted and forming an uncured protective layer and a curing process of irradiating the uncured protective layer with ultraviolet rays, thereafter, irradiating the uncured protective layer with electron beams and forming the cured protective layers 8. The optical information medium having the protective layer 8 is also manufactured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for forming a protective layer having these various performances in the field of various objects requiring antifouling properties and lubricity of the surface. The protective layer is usually formed as a hard coat layer having an appropriate hardness in order to impart scratch resistance and abrasion resistance to various object surfaces.

  In particular, the present invention relates to a method for producing an optical information medium such as a read-only optical disc, an optical recording disc, or a magneto-optical recording disc, and more specifically, has a hard coat layer on the recording and / or reproducing beam incident side surface, The present invention relates to a method for producing an optical information medium having excellent antifouling properties and lubricity on the surface, and excellent scratch resistance and wear resistance.

  Various objects that require antifouling and lubrication on the surface, such as optical information media such as CD (Compact Disk), DVD (Digital Versatile Disk), Blu-ray Disc, optical lens, optical filter, antireflection A protective layer (hard coat layer) is usually provided on the surface of various display elements such as a film and a liquid crystal display, a CRT display, a plasma display, an EL display and the like.

  On the surfaces of these various objects, contamination by various contaminants and adhesion of fingerprints occur during use. Such contamination and adhesion of fingerprints are not preferable, and an appropriate surface treatment may be applied to the surface of the object in order to improve antifouling properties, reduce fingerprint adhesion, or improve fingerprint removability. In particular, contamination or fingerprint attachment on the surface of an optical information medium may adversely affect recording / reproducing characteristics, which is not preferable. For this reason, for example, various water and oil repellent treatments have been studied on the surface of optical information media.

  Further, in order to improve the scratch resistance of the surface of the optical information medium, it is generally performed to form a transparent and scratch-resistant hard coat on the recording and / or reproducing beam incident side surface of the medium. Yes. The hard coat is formed by applying an active energy ray polymerization curable compound having two or more polymerizable functional groups such as (meth) acryloyl groups in the molecule to the surface of the medium and irradiating it with active energy rays such as ultraviolet rays. This is done by curing. However, since such a hard coat is intended only to improve the scratch resistance, it cannot be expected to have an antifouling effect against contaminants such as dust, oil mist in the atmosphere, or fingerprint stains.

  As a hard coat having an antifouling property against organic stains, for example, JP-A-10-110118 proposes kneading a non-crosslinked fluorosurfactant into a hard coat agent. The non-crosslinked fluorosurfactant has no polymerizable double bond and does not crosslink with the base resin of the hard coat agent.

  Japanese Patent Application Laid-Open No. 11-293159 proposes to incorporate both a non-crosslinked fluorine-based surfactant and a crosslinked fluorine-based surfactant into a hard coat agent. Examples of the crosslinkable fluorosurfactant include fluorinated alkyl (meth) acrylates such as perfluorooctylethyl (meth) acrylate, hexafluoropropyl (meth) acrylate, and octafluoropentyl (meth) acrylate. Such a cross-linkable fluorosurfactant has a polymerizable double bond and is cross-linked and fixed to the base resin of the hard coat agent.

  Japanese Patent Application Laid-Open No. 11-213444 discloses that a fluoropolymer is applied to the surface of a conventional optical disk substrate such as polycarbonate.

  In JP-A-2002-190136, metal chalcogenide fine particles such as silica fine particles are contained in a hard coat to improve the scratch resistance of the hard coat, and further, a silane containing a water repellent or oil repellent group on the hard coat. It is disclosed that a film of a coupling agent is provided to improve the antifouling property on the surface of the optical information medium.

  By the way, when the surface of the optical information medium is made to have a low friction coefficient, it is possible to slide and release an impact when a hard projection comes into contact, and thus it is possible to suppress the occurrence of scratches. Accordingly, it is desired to improve the scratch resistance by reducing the friction coefficient of the hard coat surface. In particular, recently, by increasing the numerical aperture (NA) of the objective lens for focusing the recording / reproducing laser beam to about 0.85 and reducing the wavelength λ of the recording / reproducing laser beam to about 400 nm, the laser beam Blu-ray Disc has been commercialized, which has a smaller condensing spot diameter and achieves a recording capacity more than four times that of DVD. When the NA is increased in this way, the working distance (working distance) between the objective lens and the surface of the optical information medium is reduced (for example, when NA = 0.85 is set, the working distance is about 100 μm). In this case, there is a very high possibility that the surface of the optical information medium and the objective lens and the support that supports the optical information medium come into contact with each other during the rotation of the optical information medium. Therefore, it is required to increase the wear resistance of the hard coat surface and at the same time reduce the friction coefficient.

  Japanese Patent Application Laid-Open No. 2002-245672 discloses an optical disc in which a substrate, a recording layer, a protective layer, and a hard coat layer are laminated in this order, and the hard coat layer contains colloidal silica fine particles and a hydrolysis product of an organosilane compound. An optical disc is disclosed which is a cured layer of a composition comprising an organic coated silica obtained by a condensation reaction, an ethylenically unsaturated compound, a slip agent, and a photopolymerization initiator. The hard coat layer is cured by ultraviolet irradiation.

JP-A-10-110118 JP-A-11-293159 JP 11-213444 A JP 2002-190136 A JP 2002-245672 A

  However, the above-described conventional techniques have problems with physical properties such as low antifouling durability of the hard coat and low hardness, and high manufacturing costs.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing an optical information medium that is excellent in antifouling properties and lubricity on the recording and / or reproducing beam incident side surface, and also excellent in scratch resistance and wear resistance.

  The object of the present invention also relates to a method for forming a protective layer or a hard coat layer having excellent antifouling properties and lubricity on the surfaces of various objects.

  As a result of intensive studies, the present inventors have found that an active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray-curable compound (B) other than the above (A) are not contained. By curing the cured hard coat layer by ultraviolet irradiation and subsequent electron beam irradiation, it is possible to obtain a hard coat layer having excellent antifouling properties and lubricity while maintaining hardness, and particularly excellent antifouling durability. I found out.

The present invention includes the following inventions.
(1) A composition for a protective layer comprising an active energy ray-reactive silicone compound and / or a fluorine compound (A) and an active energy ray-curable compound (B) on a target object to which a protective layer is to be applied. An application step of applying an object to form an uncured protective layer;
A method for forming a protective layer on a target object, comprising: irradiating an uncured protective layer with ultraviolet rays and then irradiating an electron beam to form a cured protective layer.

(2) Light having a film body composed of one or more layers including at least an information layer on a support substrate, and having a protective layer on at least one of the support substrate side and the film body side A method of manufacturing an information medium,
An active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray-curable compound (B) on at least one of the support substrate side and the film body side. An application step of forming an uncured protective layer by applying a protective layer composition comprising:
And a curing step of irradiating an uncured protective layer with ultraviolet rays and then irradiating an electron beam to form a cured protective layer.
The protective layer in the optical information medium means a so-called hard coat layer.

  (3) The silicone compound and / or fluorine compound (A) is contained in an amount of 0.01 parts by weight to 3 parts by weight with respect to 100 parts by weight of the nonvolatile content in the protective layer composition. Manufacturing method of optical information medium.

  (4) The silicone compound and / or fluorine compound (A) contained in the protective layer composition includes a silicone group and / or a fluorine group, a (meth) acryloyl group, a vinyl group, and a mercapto group. The method for producing an optical information medium according to (2) or (3), which has at least one reactive group selected from the group consisting of:

  (5) The active energy ray-curable compound (B) contained in the protective layer composition has at least one reactive group selected from the group consisting of a (meth) acryloyl group, a vinyl group and a mercapto group. A method for producing an optical information medium according to any one of (2) to (4).

  (6) The method for producing an optical information medium according to any one of (2) to (5), wherein the protective layer composition further comprises inorganic fine particles (C) having an average particle diameter of 100 nm or less.

  (7) The optical information according to (6), wherein the protective layer composition contains 5 parts by weight or more and 500 parts by weight or less of the inorganic fine particles (C) with respect to 100 parts by weight of the active energy ray-curable compound (B). A method for manufacturing a medium.

  (8) The method for producing an optical information medium according to any one of (2) to (7), wherein in the curing step, the acceleration voltage of the electron beam in electron beam irradiation is 20 to 100 kV.

  (9) The method for producing an optical information medium according to any one of (2) to (8), wherein the protective layer after curing has a thickness of 0.5 μm or more and 5 μm or less.

  The optical information medium manufacturing method of the present invention includes the following modes depending on the layer structure of the optical information medium.

1. A method for producing an optical information medium having at least an information layer, a light transmission layer, and a hard coat layer (protective layer) in this order on a support substrate,
Forming an information layer on a support substrate;
Forming a light transmission layer on the information layer;
On the light-transmitting layer, a hard coat layer composition containing an active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray-curable compound (B) is applied and uncured. An application process for forming a hard coat layer of
A curing step of irradiating an uncured hard coat layer with ultraviolet light and then irradiating an electron beam to form a cured hard coat layer.
In this optical information medium, the hard coat layer and the light transmission layer side are the recording and / or reproduction beam incident side.

2. A method for producing an optical information medium having at least an information layer and a resin layer in this order on one surface of a light-transmitting support substrate, and having a hard coat layer (protective layer) on the other surface of the support substrate. ,
Forming an information layer on one side of the support substrate;
Forming a resin layer on the information layer;
On the other surface of the support substrate, a hard coat layer composition containing an active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray curable compound (B) is applied. And an application process for forming an uncured hard coat layer,
A curing step of irradiating an uncured hard coat layer with ultraviolet light and then irradiating an electron beam to form a cured hard coat layer.
In this optical information medium, the hard coat layer and the supporting substrate side are the recording and / or reproducing beam incident side.

  According to the present invention, an optical information medium excellent in antifouling property and lubricity on the recording and / or reproducing beam incident side surface and excellent in scratch resistance and wear resistance, particularly on the recording and / or reproducing beam incident side surface. An optical information medium excellent in antifouling durability is produced.

  Further, according to the present invention, a protective layer or a hard coat layer having excellent antifouling properties and lubricity is formed on the surfaces of various objects.

  A method for producing an optical information medium (hereinafter sometimes abbreviated as “optical disk”) of the present invention will be described with reference to the drawings.

1. Manufacturing method of optical information medium in which hard coat layer and light transmission layer side are recording / reproducing beam incident side:
FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of an optical disc manufactured in the present invention. This optical disk is a recording medium, and has a recording layer (4) as an information layer on a support base (20) having a relatively high rigidity, and a light transmission layer (7) on the recording layer (4). A light-transmitting hard coat layer (8) is provided on the light-transmitting layer (7). The hard coat layer (8) is the recording / reproducing beam incident side, and a laser beam for recording or reproducing is incident on the recording layer (4) through the hard coat layer (8) and the light transmission layer (7). The thickness of the light transmission layer (7) is preferably 10 to 300 μm, more preferably 70 to 150 μm. Such an optical disc is, for example, a Blu-ray Disc. As the optical disc, the hard coat layer (8) preferably has a hardness of H or more in a pencil hardness test.

  Although not shown, an optical disc having two or more recording layers in which a recording layer is further provided on the recording layer (4) via a spacer layer is also included in the present invention. In this case, the optical disc has a light transmission layer (7) and a hard coat layer (8) on the recording layer farthest from the support base (20).

  The present invention can be applied regardless of the type of the recording layer. That is, for example, it can be applied to a phase change recording medium, a pit formation type recording medium, and a magneto-optical recording medium. Normally, a dielectric layer and a reflective layer are provided on at least one side of the recording layer for the purpose of protecting the recording layer and optical effects, but the illustration is omitted in FIG. In the present invention, the information layer means that it includes at least a recording layer and also includes a dielectric layer and a reflective layer formed as necessary. Further, the present invention is not limited to the recordable type as shown in the figure, but can be applied to a reproduction-only type. In that case, a pit row is formed integrally with the support substrate (20), and a reflective layer (metal layer or dielectric multilayer film) covering the pit row forms an information layer.

In the present invention, an optical information medium in the case of a phase change recording medium and a manufacturing method thereof will be described.
FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the optical disk manufactured in the present invention. In FIG. 2, the optical disk has a reflective layer (3), a second dielectric layer (52), and phase change recording on the surface of the support base (20) on which fine irregularities such as information pits and grooves are formed. It has a material layer (4) and a first dielectric layer (51) in this order, a light transmission layer (7) on the first dielectric layer (51), and a hard layer on the light transmission layer (7). It has a coat layer (8). In this example, the reflective layer (3), the second dielectric layer (52), the phase change recording material layer (4) and the first dielectric layer (51) constitute an information layer. The information layer and the light transmission layer (7) constitute a film body necessary for recording or reproduction. This optical disk is used so that a laser beam for recording or reproduction enters through the hard coat layer (8) and the light transmission layer (7), that is, from the film body side.

  The support base (20) has a thickness of 0.3 to 1.6 mm, preferably 0.4 to 1.3 mm. On the surface on which the recording layer (4) is formed, information pits, grooves, etc. The fine irregularities are formed.

  The support substrate (20) is used so that the laser beam is incident through the hard coat layer (8) and the light transmission layer (7) as described above, but it is not necessary to be optically transparent. As the material, polycarbonate resin, acrylic resin such as polymethyl methacrylate (PMMA), various plastic materials such as polyolefin resin, and the like can be used. Alternatively, glass, ceramics, metal, or the like may be used. In the case of using a plastic material, the concavo-convex pattern is often created by injection molding, and in the case of other than the plastic material, it is formed by a photopolymer method (2P method).

  An information layer is formed on the support substrate (20). In the example of FIG. 2, a reflective layer (3), a second dielectric layer (52), a phase change recording material layer (4), and a first dielectric layer (51) are formed on a support base (20). An information layer is formed. The reflective layer (3) may not be provided.

  On the support substrate (20), the reflective layer (3) is usually formed by sputtering. As a material for the reflective layer, a metal element, a metalloid element, a semiconductor element, or a compound thereof is used alone or in combination. Specifically, for example, a known reflective layer material such as Au, Ag, Cu, Al, or Pd may be selected. The reflective layer is preferably formed as a thin film having a thickness of 20 to 200 nm.

  The second dielectric layer (52), the phase change recording material layer (4), the first dielectric layer (51) directly on the reflective layer (3) or directly on the support base (20) when there is no reflective layer. ) In this order by sputtering.

  The phase change recording material layer (4) is reversibly changed between a crystalline state and an amorphous state by laser light irradiation, and is formed of a material having different optical characteristics between the two states. For example, Ge—Sb—Te, In—Sb—Te, Sn—Se—Te, Ge—Te—Sn, In—Se—Tl, In—Sb—Te, and the like can be given. Further, these materials contain a trace amount of at least one of metals selected from Co, Pt, Pd, Au, Ag, Ir, Nb, Ta, V, W, Ti, Cr, Zr, Bi, In, and the like. It may be added, or a reducing gas such as nitrogen may be added in a trace amount. The thickness of the recording material layer (4) is not particularly limited and is, for example, about 3 to 50 nm.

  The second dielectric layer (52) and the first dielectric layer (51) are formed on both sides of the upper and lower surfaces of the recording material layer (4). The second dielectric layer (52) and the first dielectric layer (51) have a function as an interference layer for adjusting optical characteristics as well as a mechanical and chemical protection function of the recording material layer (4). Each of the second dielectric layer (52) and the first dielectric layer (51) may be composed of a single layer or a plurality of layers.

  The second dielectric layer (52) and the first dielectric layer (51) are respectively Si, Zn, Al, Ta, Ti, Co, Zr, Pb, Ag, Zn, Sn, Ca, Ce, V, Cu, It is preferably formed from an oxide, nitride, sulfide, fluoride, or a composite thereof containing at least one of metals selected from Fe and Mg. The extinction coefficient k of each of the second dielectric layer (52) and the first dielectric layer (51) is preferably 0.1 or less.

  The thickness of the second dielectric layer (52) is not particularly limited, and is preferably about 20 to 150 nm, for example. The thickness of the first dielectric layer (51) is not particularly limited, and is preferably about 20 to 200 nm, for example. The reflection can be adjusted by selecting the thicknesses of the two dielectric layers (52) and (51) within such a range.

  On the information layer, that is, on the first dielectric layer (51), the light transmission layer (7) is formed using an active energy ray curable material or a light transmission sheet such as a polycarbonate sheet.

  The active energy ray-curable material used for the light transmissive layer (7) is UV curable on the condition that it is optically transparent, has little optical absorption and reflection in the used laser wavelength region, and has low birefringence. Select from materials and electron beam curable materials.

  Specifically, the active energy ray curable material is preferably composed of an ultraviolet ray (electron beam) curable compound or a composition for polymerization thereof. Examples of such compounds include ester compounds of acrylic acid and methacrylic acid, acrylic double bonds such as epoxy acrylate and urethane acrylate, allyl double bonds such as diallyl phthalate, and unsaturated double bonds such as maleic acid derivatives. Mention may be made of monomers, oligomers, polymers, etc. containing or introduced in the molecule a group which is crosslinked or polymerized by ultraviolet irradiation such as bonding. These are preferably polyfunctional, particularly trifunctional or more, and may be used alone or in combination of two or more. Moreover, you may use a monofunctional thing as needed.

  As the UV curable monomer, a compound having a molecular weight of less than 2000 is preferable, and as the oligomer, a molecular weight of 2000 to 10,000 is preferable. Examples of these include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, and the like. Examples thereof include pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, and (meth) acrylate of a phenol ethylene oxide adduct. . In addition, examples of the ultraviolet curable oligomer include oligoester acrylate and an acrylic modified product of urethane elastomer.

  The ultraviolet (electron beam) curable material may contain a known photopolymerization initiator. The photopolymerization initiator is not particularly required when an electron beam is used as the active energy ray, but is required when ultraviolet rays are used. The photopolymerization initiator may be appropriately selected from ordinary ones such as acetophenone, benzoin, benzophenone, and thioxanthone. Among the photopolymerization initiators, examples of the photo radical initiator include Darocur 1173, Irgacure 651, Irgacure 184, and Irgacure 907 (all manufactured by Ciba Specialty Chemicals). The content of the photopolymerization initiator is, for example, about 0.5 to 5% by weight with respect to the ultraviolet (electron beam) curable component.

  Moreover, as an ultraviolet curable material, the composition containing an epoxy compound and a photocationic polymerization catalyst is also used suitably. As the epoxy compound, an alicyclic epoxy compound is preferable, and an epoxy compound having two or more epoxy groups in the molecule is particularly preferable. Examples of alicyclic epoxy compounds include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis- (3,4-epoxycyclohexylmethyl) adipate, bis- (3,4-epoxycyclohexyl) adipate, One or more of 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (2,3-epoxycyclopentyl) ether, vinylcyclohexene dioxide and the like are preferable. . Although there is no restriction | limiting in particular in the epoxy equivalent of an alicyclic epoxy compound, Since favorable sclerosis | hardenability is obtained, it is preferable that it is 60-300, especially 100-200.

  Any known photocationic polymerization catalyst may be used without any particular limitation. For example, one or more metal fluoroborate and boron trifluoride complexes, bis (perfluoroalkylsulfonyl) methane metal salts, aryldiazonium compounds, 6A group aromatic onium salts, 5A group aromatic onium salts, A dicarbonyl chelate, a thiopyrylium salt, an MF6 anion (where M is P, As or Sb), a triarylsulfonium complex salt, an aromatic iodonium complex salt, an aromatic sulfonium complex salt, etc. In particular, it is preferable to use one or more of polyarylsulfonium complex salts, aromatic sulfonium salts or iodonium salts of halogen-containing complex ions, aromatic onium salts of 3A group elements, 5A group elements, and 6A group elements. Content of a photocationic polymerization catalyst is about 0.5 to 5 weight% with respect to the said ultraviolet curable component, for example.

  As the active energy ray-curable material used for the light transmission layer, a material having a viscosity of 1,000 to 10,000 cp (25 ° C.) is preferable.

  In the formation of the light transmission layer (7), the application of the active energy ray-curable material on the first dielectric layer (51) may be performed by a spin coating method. The curable material after application may be cured by irradiating with ultraviolet rays. Active energy rays used for curing include electron beams and visible light in addition to ultraviolet rays, but ultraviolet rays are preferred. The ultraviolet irradiation at this time may be performed in a plurality of times. In addition, the application operation of the active energy ray-curable material may be performed in a plurality of times, and ultraviolet irradiation may be performed after each application operation. By curing the resin stepwise by performing ultraviolet irradiation in a plurality of times, it is possible to reduce the stress due to curing shrinkage that accumulates on the disk at one time, and finally the stress that accumulates on the disk is reduced. As a result, even when the light transmission layer (7) is thick as described above, a disk having excellent mechanical properties can be produced, which is preferable.

  Or in this invention, a light transmissive layer can also be formed using a light transmissive resin sheet. In this case, an active energy ray-curable material similar to that for the light transmission layer is applied on the first dielectric layer (51) to form an uncured resin material layer. A light transmissive sheet as a light transmissive layer (7) is placed on the uncured resin material layer, and then the resin material layer is cured by irradiating with active energy rays such as ultraviolet rays. The sheet is adhered to form a light transmission layer (7). As the active energy ray-curable material used for the resin material layer, a material having a viscosity (25 ° C.) of 3 to 500 cp is preferable. The resin material layer may be applied by a spin coating method. The thickness of the resin material layer is preferably about 1 to 50 μm after curing, for example.

  As the light transmissive sheet, for example, a polycarbonate sheet having a desired thickness selected from 30 to 150 μm is used. More specifically, the light transmitting layer (7) is formed by placing a polycarbonate sheet having a desired thickness on an uncured resin material layer in a vacuum (0.1 atm or less), The atmosphere is returned to atmospheric pressure, and the resin material layer is cured by irradiating with ultraviolet rays.

  A hard coat layer containing an active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray-curable compound (B) other than the above (A) on the light transmission layer (7) The composition for coating is applied to form an uncured hard coat layer, the uncured hard coat layer is irradiated with ultraviolet rays, and then irradiated with an electron beam to form a cured hard coat layer (8). Each component of the composition for hard coat layers will be described.

  The active energy ray-curable compound (B) contained in the hard coat layer composition is a main component of the curable component in the hard coat layer composition, and forms a matrix of the hard coat layer obtained after curing. is there. The active energy ray-curable compound (B) is other than the silicone compound and / or the fluorine compound (A) and has at least one activity selected from a (meth) acryloyl group, a vinyl group, and a mercapto group. The structure is not particularly limited as long as it is a compound having an energy beam polymerizable group. The active energy ray-curable compound (B) contains a polyfunctional monomer or oligomer containing two or more, preferably three or more polymerizable groups in one molecule in order to obtain sufficient hardness as a hard coat. It is preferable.

  Among such active energy ray-curable compounds (B), examples of the compound having a (meth) acryloyl group include 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, and ethylene. Oxide-modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meta) ) Acrylate, 3- (meth) acryloyloxyglycerin mono (meth) acrylate, urethane acrylate, epoxy acrylate, ester acrylate, etc. Not intended to be.

  Examples of the compound having a vinyl group include ethylene glycol divinyl ether, pentaerythritol divinyl ether, 1,6-hexanediol divinyl ether, trimethylolpropane divinyl ether, ethylene oxide-modified hydroquinone divinyl ether, and ethylene oxide-modified bisphenol A diester. Examples include vinyl ether, pentaerythritol trivinyl ether, dipentaerythritol hexavinyl ether, ditrimethylolpropane polyvinyl ether, and the like, but are not necessarily limited thereto.

  Examples of the compound having a mercapto group include ethylene glycol bis (thioglycolate), ethylene glycol bis (3-mercaptopropionate), trimethylolpropane tris (thioglycolate), trimethylolpropane tris (3- Mercaptopropionate), pentaerythritol tetrakis (mercaptoacetate), pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (3-mercaptopropionate), and the like, but are not necessarily limited thereto.

  As an active energy ray hardening compound (B) contained in the composition for hard-coat layers, only 1 type may be used and 2 or more types may be used together.

  The active energy ray-reactive silicone compound and / or fluorine compound (A) is used to impart antifouling properties (water repellency and / or oil repellency) and / or lubricity to the surface of the hard coat layer. Examples of the group for imparting antifouling properties and / or lubricity include a silicone group and a fluorine group. Active energy ray reactive groups include active energy ray radical polymerizable reactive groups such as (meth) acryloyl group, vinyl group and mercapto group, and active energy ray cationic polymerizable reactions such as cyclic ether group and vinyl ether group. Sex groups. When the compound (A) has an active energy ray-reactive group, a crosslinking reaction between the compounds (A) or an active energy ray-curable compound (B) is caused by active energy ray irradiation when the hard coat is cured. Cross-linking reaction occurs, and immobilization in the hard coat layer is improved. Accordingly, a silicone compound or a fluorine compound having such a radical polymerizable reactive group or a cationic polymerizable reactive group can be used as the compound (A). The active energy ray reactive group is preferably a radical polymerizable reactive group, more preferably a (meth) acryloyl group from the viewpoint of reactivity.

  The silicone compound includes a reactive silicone having a silicone group and at least one reactive group selected from a (meth) acryloyl group, a vinyl group, a mercapto group, a cyclic ether group, and a vinyl ether group. More specifically, examples include compounds represented by the following formulas (1) to (3), but are not necessarily limited thereto.

_{R- [Si (CH 3) 2} O] n-R (1)
_{R- [Si (CH 3) 2} O] n-Si (CH 3) 3 (2)
_{(CH 3) 3 SiO - [} Si (CH 3) 2 0] n- [Si (CH 3) (R) O] m-Si (CH 3) 3 (3)
Here, R is a substituent containing at least one reactive group selected from a (meth) acryloyl group, a vinyl group, a mercapto group, a cyclic ether group, and a vinyl ether group, and n and m are polymerization degrees, respectively. N is 5 to 1000, and m is 2 to 100.

  As the silicone compound (A), those having two or more active energy ray reactive groups in the molecule are preferable because immobilization in the hard coat layer is improved and antifouling property and lubricity are also improved. .

The average molecular weight of the silicone compound (A) is preferably 1.0 × 10 ² or more and 1.5 × 10 ⁴ or less. When the average molecular weight is less than 1.0 × 10 ² , the above-described lubricity-imparting performance is hardly exhibited, and when the average molecular weight exceeds 1.5 × 10 ⁴ , the compatibility in the composition for the hard coat layer decreases. There is a tendency that uniform application becomes difficult.

  Specific examples of the silicone-based compound (A) include X-22-164A, X-22-164B, and X-22-164C (both are bifunctional silicone methacrylates; manufactured by Shin-Etsu Chemical Co., Ltd.), L7001 (Japan) Unicar Co., Ltd.).

  As a compound (A) contained in the composition for hard-coat layers, only 1 type of said silicone type compound may be used, and 2 or more types may be used together.

  Examples of the fluorine compound include a compound having a moiety having a fluorine-containing group and at least one reactive group selected from a (meth) acryloyl group, a vinyl group, a mercapto group, a cyclic ether group, and a vinyl ether group. It is done.

  As a fluorine-type compound, a fluorine-containing (meth) acrylate compound is mentioned, for example. Specifically, for example, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 2,2,2-trifluoroethyl (Meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl (meth) acrylate, 2- (perfluorooctyl) ethyl acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, 2- (perfluoro-9-methyloctyl) ethyl (meth) acrylate, 3- (perfluoro -7-methyloctyl) ethyl (meth) acrylate, 2- (perfluoro-9-methyldecyl) ethyl (meth) acrylate, 1H, 1H, 9H-hexade Fluorinated acrylates such as fluoro nonyl (meth) acrylate, and the like, but not necessarily limited thereto.

  As the fluorine compound, for example, a polymer compound such as perfluoropolyether having a (meth) acrylate group introduced therein, or a fluorine compound having a vinyl group or a mercapto group in place of the (meth) acrylate group is preferably used. Can do. Specific examples include Fombrin Z DOL (alcohol-modified perfluoropolyether (Audimont)) diacrylate, fluorite ART3, and fluorite ART4 (Kyoeisha Chemical).

  As the fluorine-based compound (A), those having two or more active energy ray reactive groups in the molecule are preferable because immobilization in the hard coat layer is improved and antifouling property and lubricity are also improved. .

  As a compound (A) contained in the composition for hard-coat layers, only 1 type of said fluorine type compound may be used, and 2 or more types may be used together.

  In the present invention, the hard coat layer composition is 0.01 parts by weight or more and 3 parts by weight as the total amount of the silicone compound and / or the fluorine compound (A) with respect to 100 parts by weight of the nonvolatile content in the composition. It is preferable to include the following, and it is more preferable to include 0.05 part by weight or more and 1 part by weight or less. When the compound (A) is contained in an amount of more than 3 parts by weight, the lubricity is improved, but the hardness of the hard coat layer tends to be low. On the other hand, when it is less than 0.01 parts by weight, the effect of improving the lubricity is weak. Here, the non-volatile content is a component remaining in the hard coat layer after curing, and in addition to the compound (A) and the curable compound (B), a monofunctional monomer, inorganic fine particles (C) described later, and photopolymerization start Ingredients such as additives and various additives are included.

  In the present invention, the hard coat layer composition preferably contains inorganic fine particles (C) having an average particle size of 100 nm or less. The average particle size of the inorganic fine particles (C) is 100 nm or less, preferably 20 nm or less in order to ensure the transparency of the hard coat layer, and is preferably 5 nm or more due to restrictions on the production of the colloidal solution.

  The inorganic fine particles (C) are, for example, fine particles of metal (or metalloid) oxide or fine particles of metal (or metalloid) sulfide. Examples of the inorganic fine metal or metalloid include Si, Ti, Al, Zn, Zr, In, Sn, and Sb. In addition to oxides and sulfides, Se, Te, nitrides, and carbides can also be used. Examples of the inorganic fine particles include fine particles of silica, alumina, zirconia, titania and the like, and silica fine particles are preferable. By adding such inorganic fine particles to the hard coat layer composition, the wear resistance of the hard coat layer can be further improved.

  Among the silica fine particles, those having a surface modified with a hydrolyzable silane compound having an active energy ray reactive group are preferably used. Such reactive silica fine particles undergo a crosslinking reaction by irradiation with active energy rays when the hard coat is cured, and are fixed in the polymer matrix. Examples of such reactive silica fine particles include reactive silica particles described in JP-A-9-100111, and can be preferably used in the present invention.

  In the present invention, when the inorganic fine particles (C) are used in the hard coat layer composition, the inorganic fine particles (C) are used in an amount of 5 parts by weight to 500 parts by weight with respect to 100 parts by weight of the curable compound (B). The inorganic fine particles (C) are preferably contained in an amount of 20 parts by weight or more and 200 parts by weight or less. If the inorganic fine particles (C) are contained in an amount of more than 500 parts by weight, the film strength of the hard coat layer tends to be weak, whereas if it is less than 5 parts by weight, the wear resistance of the hard coat layer is improved by adding the inorganic fine particles (C). The effect is weak.

  In the present invention, the hard coat layer composition contains a known photopolymerization initiator. The photopolymerization initiator is not particularly necessary for curing using an electron beam as an active energy ray, but is necessary for curing using ultraviolet rays. The photopolymerization initiator may be appropriately selected from ordinary ones such as acetophenone, benzoin, benzophenone, and thioxanthone. Among the photopolymerization initiators, examples of the photo radical initiator include Darocur 1173, Irgacure 651, Irgacure 184, and Irgacure 907 (all manufactured by Ciba Specialty Chemicals). Content of a photoinitiator is about 0.5 to 5 weight% with respect to the sum total of said (A), (B), and (C), for example in the composition for hard-coat layers.

  Moreover, when using what has a cyclic ether group or a vinyl ether group as a reactive group as a compound (A) and / or a compound (B), the photocationic polymerization catalyst mentioned above is used. Content of a photocationic polymerization catalyst is about 0.5 to 5 weight% with respect to the sum total of said (A), (B), and (C), for example in the composition for hard-coat layers.

  Further, the composition for a hard coat layer of the present invention may further comprise a non-polymerizable diluent solvent, an organic filler, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, an antifoaming agent, and a leveling as necessary. An agent, a pigment, a silicon compound, etc. may be included.

  The composition for hard coat layers can be produced by mixing the above-mentioned components by a conventional method. The hard coat layer composition may be adjusted to a viscosity suitable for coating. As described above, the hard coat layer composition used in the present invention is constituted.

  On the light transmission layer (7), the above-mentioned composition for hard coat layer is applied to form an uncured hard coat layer. The coating method of the hard coat layer composition is not limited, and various coating methods such as spin coating, dip coating, and gravure coating may be used. When the hard coat layer composition is applied, the light transmission layer (7) and the hard coat layer are more semi-cured near the surface than the light transmission layer (7) is completely cured. This is preferable because the adhesiveness to the layer (8) becomes higher.

  When the hard coat layer composition contains a non-reactive diluted organic solvent, the hard coat layer composition is applied to form an uncured hard coat layer, and then the non-reactive organic solvent is added. After removing by heat drying, the active energy ray is irradiated to cure the uncured layer to form a hard coat layer (8). By applying the composition for a hard coat layer using a diluted organic solvent and removing the organic solvent by heating and drying, the compound (A) is more likely to gather near the surface of the uncured hard coat layer, and after curing. More compound (A) is present in the vicinity of the surface of the hard coat layer (8), and a greater lubricity improving effect is easily obtained by the silicone group and / or fluorine-containing group. In this case, the heat drying temperature is preferably 40 ° C. or more and 100 ° C. or less, for example. The heat drying time is, for example, 30 seconds to 8 minutes, preferably 1 minute to 5 minutes, more preferably 3 minutes to 5 minutes. The non-reactive diluted organic solvent is not particularly limited, and propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol and the like are used.

  In the present invention, the uncured hard coat layer is first irradiated with ultraviolet rays, and then irradiated with an electron beam to cure the hard coat layer. By performing the curing process in the order of irradiation of active energy rays, a hard coat having a very excellent antifouling durability on the surface is obtained by immobilizing more compound (A) near the surface of the hard coat layer (8) after curing. Layer (8) is formed. Although the detailed reason is not clear, it is considered as follows.

  The compound (A) that imparts antifouling properties and / or lubricity to the surface of the hard coat layer is harder to be cured by ultraviolet irradiation than the curable compound (B) to be a matrix, and is easily cured by electron beam irradiation. When the uncured hard coat layer is first irradiated with ultraviolet rays, the curable compound (B) is more easily cured in the inner part than in the vicinity of the surface of the hard coat layer. Heated. Then, in the process of ultraviolet irradiation, the hard coat layer is heated, whereby the compound (A) having surface active properties is likely to gather near the surface, and the curable compound (B) near the surface is not yet cured. Furthermore, the compound (A) is in an environment that tends to gather near the surface. In this way, the compound (A) is more concentrated in the vicinity of the surface after the ultraviolet irradiation. By irradiation with an electron beam in this state, the compound (A) is more immobilized near the surface. By immobilizing more compound (A) near the surface of the hard coat layer (8), a greater antifouling property and lubricity improving effect on the hard coat layer surface can be obtained. High durability is obtained.

At this time, the amount of UV irradiation depends on the thickness of the hard coat layer (8), but when the light transmission layer (7) using the active energy linear material is semi-cured, the light transmission layer (7 ) of depending on the thickness, for example 500~5000mJ / cm ^2, may preferably be a 1000~4000mJ / cm ^2. When the light transmission layer (7) is in a semi-cured state, a larger amount of UV irradiation is required to completely cure the light transmission layer (7).

  The irradiation amount of the electron beam after the ultraviolet irradiation is, for example, 5 to 500 kGy, preferably 10 to 100 kGy. The acceleration voltage of the electron beam is, for example, 20 to 100 kV, preferably 30 to 70 kV. With this amount of electron beam irradiation and acceleration voltage, the compound (A) can be efficiently cured and fixed, and further, the information layer can be prevented from being damaged by the electron beam. If the acceleration voltage of the electron beam exceeds 100 kV, the information layer may be damaged.

  In addition, it is preferable to perform purging with an inert gas such as nitrogen so that the oxygen concentration in the atmosphere is 500 ppm or less, preferably 200 ppm or less, more preferably 10 ppm or less during ultraviolet irradiation and electron beam irradiation. . This is in order to suppress surface hardening inhibition caused by oxygen radicals generated in the irradiation atmosphere. Alternatively, instead of controlling the oxygen concentration in the irradiation atmosphere, various conventionally known oxygen inhibition inhibitors may be added to the hard coat layer composition. As such an oxygen inhibition inhibitor, for example, oxygen inhibition inhibitors described in JP2000-109828A, JP2000-109828A, and JP2000-144011A can be used. Needless to say, the oxygen inhibition inhibitor and oxygen concentration control in the irradiation atmosphere may be used in combination.

  The film thickness of the hard coat layer (8) after curing is preferably about 0.5 to 5 μm. If the film thickness is greater than 5 μm, cracks are likely to occur in the hard coat layer, while if the film thickness is less than 0.5 μm, the wear resistance of the hard coat layer tends to be low.

  Alternatively, when a light-transmitting sheet is used as the light-transmitting layer (7), a hard coat layer (8) is formed in advance on the long light-transmitting sheet original fabric in the same manner as described above, and this original After punching the substrate into a disc shape, it may be placed on an uncured resin material layer as described above to cure the resin material layer.

  As described above, the phase change type optical recording disk illustrated in FIG. 2 is obtained as an optical information medium in which the hard coat layer and the light transmission layer side are the recording / reproducing beam incident side surface.

2. Manufacturing method of optical information medium in which hard coat layer and supporting substrate side are recording / reproducing beam incident side:
FIG. 3 is a schematic cross-sectional view showing another layer configuration example of the optical disc manufactured in the present invention. The optical disk illustrated in FIG. 3 has an information layer (4) on one surface of a light-transmissive support base (20) and a resin layer (6) on the information layer (4). ) On the other surface is provided with a light-transmitting hard coat layer (8). The hard coat layer (8) is on the recording / reproducing beam incident side, and a laser beam for recording or reproducing is incident on the recording layer (4) through the hard coat layer (8) and the support substrate (20).

  FIG. 4 is a schematic cross-sectional view showing another layer configuration example of the optical disc manufactured in the present invention. The optical recording disk illustrated in FIG. 4 includes an organic dye layer (4), a reflective layer (3) on the dye layer (4), and a reflective layer (1) on one surface of a light-transmitting support substrate (20). 3) a support base (21) bonded via a resin layer (61) on top, and a light-transmitting hard coat layer (8) on the other surface of the support base (20). The coating layer (8) is the recording / reproducing beam incident side. In this example, the dye layer (4) and the reflective layer (3) constitute an information layer. As such an optical disk, there is a write-once type DVD-R.

  In addition to the write-once type DVD-R illustrated in FIG. 4, various types such as a read-only type DVD-ROM, a rewritable type DVD-RAM, and a DVD-RW have been commercialized. As read-only DVDs, there are DVD-Video, DVD-ROM, and the like, but in these optical discs, irregularities called pits on which information signals are recorded are formed when a light-transmissive support base is formed, A metal reflective layer such as Al is formed thereon, and a resin layer is further formed. Another support substrate is bonded through the resin layer to form a final optical disc. In the case of a rewritable DVD, the above 1. The information layer may be configured in the same manner as described for the phase change recording medium.

  As the support base (20), a light transmissive substrate is used. Conventionally, the light transmissive support substrate (20) is formed by injection-molding polycarbonate resin, and various information such as pre-pits and pre-grooves are formed on the surface thereof, but the material used is not limited to this, Resins such as polyolefin resins are also preferably used. Alternatively, it can be obtained by forming prepits or grooves on a glass flat plate by the 2P method.

  On the support substrate (20), an organic dye dissolved in a solvent is applied by spin coating, and dried to form an organic dye layer (4) having a desired film thickness. The organic dye is selected from various cyanine dyes, azo dyes, phthalocyanine dyes, and the like. As a method for forming the dye layer, a spray method, a screen printing method, and a vapor deposition method can be applied in addition to the spin coating method, and the film thickness to be formed is appropriately selected depending on the dye to be used.

  When applying the spin coating method, the dye component is dissolved in a solvent and used as an organic dye solution. Select a solvent that can sufficiently dissolve the dye and does not adversely affect the transparent substrate. Use. The concentration is preferably about 0.01 to 10% by weight.

  Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, octafluoropentanol, allyl alcohol, methyl cellosolve, ethyl cellosolve, tetrafluoropropanol; hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, ethylcyclohexane, Aliphatic or alicyclic hydrocarbon solvents such as dimethylcyclohexane; aromatic hydrocarbon solvents such as toluene, xylene and benzene; halogenated hydrocarbon solvents such as carbon tetrachloride, chloroform, tetrachloroethane and dibromoethane; diethyl Ether solvents such as ether, dibutyl ether, diisopropyl ether, dioxane; ketone solvents such as 3-hydroxy-3-methyl-2-butanone; ethyl acetate, methyl lactate Ester-based solvents; water and the like, can be used from among these does not attack the substrate material. These may be used singly or in combination of two or more.

  The thickness of the organic dye layer is not particularly limited, but is preferably about 10 to 300 nm, and particularly about 60 to 250 nm.

  A reflective layer (3) is provided on the organic dye layer (4). As a material for the reflective layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, an element such as Au, Ag, Cu, Al, Ni, Pd, Cr, or Pt is used alone or as an alloy. In addition to the above, the following may be included. For example, Mg, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Zn, Cd, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, etc. A metal, a semimetal, etc. can be mentioned.

  Examples of the formation of the reflective layer include a sputtering method, an ion plating method, a chemical vapor deposition method, a vacuum vapor deposition method, and the like, but are not limited to these examples. In addition, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or under the reflective layer in order to improve reflectivity or improve recording characteristics. The thickness of the reflective layer is not particularly limited, but is preferably about 10 to 300 nm, and particularly about 80 to 200 nm.

On the reflective layer (3), a support substrate (21) is usually bonded via a resin layer (61). The support base (21) is the same as the support base (20). The material of the resin layer (61) is not particularly limited as long as it can protect the reflective layer from external force, and a known organic substance or inorganic substance can be used. Examples of the organic substance include a thermoplastic resin, a thermosetting resin, and an ultraviolet curable resin. Examples of inorganic substances include SiO ₂ , SiN ₄ , MgF ₂ , SnO _{2 and the} like. A thermoplastic resin, a thermosetting resin, etc. can be formed by dissolving in an appropriate solvent, applying a coating solution, and drying. The ultraviolet curable resin can be formed by preparing a coating solution as it is or by dissolving it in a suitable solvent, and then applying the coating solution and curing it by irradiating with ultraviolet rays. As the ultraviolet curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or in combination, and may be used as a multilayer film as well as a single layer. The resin layer (61) may serve as an adhesive layer for bonding the two supporting substrates (20) and (21).

  As the method for forming the resin layer (61), as with the recording layer, a coating method such as a spin coating method or a casting method, a method such as a sputtering method or a chemical vapor deposition method is used.

  An adhesive layer may be formed on the resin layer (61). As the adhesive, a hot melt adhesive, an ultraviolet curable adhesive, a heat curable adhesive, an adhesive adhesive, and the like are used, and suitable methods such as a roll coater method, a screen printing method, and a spin coating method are used. Etc., an adhesive layer is formed. In the case of DVD-R, a screen printing method or a spin coating method is used using an ultraviolet curable adhesive comprehensively determined from workability, productivity, disk characteristics, and the like.

  On the other hand, a light-transmitting hard coat layer (8) is formed on the other surface of the support substrate (20). The material and forming method of the hard coat layer (8) are as follows. This is the same as described in. More compound (A) is fixed in the vicinity of the surface of the hard coat layer (8) after curing, and a hard coat layer (8) having excellent surface antifouling durability is formed. The hard coat layer (8) is the recording / reproducing beam incident side. As the recording / reproducing beam, a laser beam having a wavelength of 650 nm or 660 nm is used. A blue laser beam is also used.

  As described above, the DVD-R illustrated in FIG. 4 is obtained as an optical information medium in which the hard coat layer and the supporting substrate side are the recording / reproducing beam incident side.

  The hard coat layer formation on the surface of the optical information medium has been described above. In the present invention, the formation of a hard coat layer on the surface of various objects other than the optical information medium can also be carried out using the same hard coat layer composition as described above, by an appropriate coating method, and after irradiation with ultraviolet rays. It can carry out by performing the hardening process by a beam irradiation.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[Example 1]
An optical recording disk sample having the layer structure shown in FIG. 2 was produced as follows.
Al ₉₈ Pd ₁ Cu ₁ (atomic ratio) is formed on the surface of the disk-shaped support base (20) (made of polycarbonate, diameter 120 mm, thickness 1.1 mm) on which grooves are formed for information recording. A reflective layer (3) having a thickness of 100 nm was formed by sputtering. The depth of the groove was λ / 6 expressed by the optical path length at the wavelength λ = 405 nm. The recording track pitch in the groove recording system was 0.32 μm.

Next, a second dielectric layer (52) having a thickness of 20 nm was formed on the surface of the reflective layer (3) by sputtering using an Al ₂ O ₃ target. A recording layer (4) having a thickness of 12 nm was formed on the surface of the second dielectric layer (52) by sputtering using an alloy target made of a phase change material. The composition (atomic ratio) of the recording layer (4) was Sb ₇₄ Te ₁₈ (Ge ₇ In ₁ ). The recording layer (4) surface, ZnS (80 mol%) - by SiO ₂ (20 mol%) sputtering method using a target, thereby forming a first dielectric layer having a thickness of 130 nm (51).

Next, a radical polymerizable ultraviolet curable material having the following composition was applied to the surface of the first dielectric layer (51) by spin coating, the irradiation intensity was 160 W / cm, the distance from the lamp was 11 cm, and the integrated light quantity was 200 mJ / cm. ^The light transmitting layer (7) was formed by irradiating ultraviolet rays at ² so that the thickness after curing was 98 μm. The vicinity of the surface of the light transmission layer (7) was in a semi-cured state.

(Light transmission layer: Composition of UV curable material)
50 parts by weight of urethane acrylate oligomer (Made by Mitsubishi Rayon Co., Ltd., Diabeam UK6035)
Isocyanuric acid EO-modified triacrylate 10 parts by weight (Aronix M315, manufactured by Toa Gosei Co., Ltd.)
Isocyanuric acid EO-modified diacrylate 5 parts by weight (manufactured by Toa Gosei Co., Ltd., Aronix M215)
Tetrahydrofurfuryl acrylate 25 parts by weight Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) 3 parts by weight

  Next, an ultraviolet / electron beam curable hard coating agent having the following composition is applied onto the light transmission layer (7) by spin coating to form a film, and the inside of the film is diluted by heating at 80 ° C. for 3 minutes in the air. The solvent was removed to form an uncured hard coat layer.

(Composition of hard coating agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl ether acetate, nonvolatile content: 40% by weight) 100 parts by weight dipentaerythritol hexaacrylate 48 parts by weight tetrahydrofurfuryl acrylate 12 parts by weight propylene glycol monomethyl ether acetate 40 parts by weight ( Non-reactive diluent solvent)
Photopolymerization initiator (1-hydroxycyclohexyl phenyl ketone) 5 parts by weight X-22-164C (manufactured by Shin-Etsu Chemical Co., Ltd., dimethyl-modified polydimethylsiloxane) 0.40 parts by weight

Hard coat layer curing process:
The uncured hard coat layer was irradiated with ultraviolet rays at an irradiation intensity of 280 W / cm, a distance from the lamp of 11 cm and an integrated light quantity of 3000 mJ / cm ² under a nitrogen stream, and then further irradiated with an electron beam under a nitrogen stream. Thus, the light transmission layer (7) and the hard coat layer (8) were completely cured. An electron beam irradiation apparatus Min-EB (manufactured by Toyo Ink Manufacturing Co., Ltd.) was used, the electron beam acceleration voltage was 50 kV, and the irradiation dose was 10 kGy. The oxygen concentration in the ultraviolet irradiation and electron beam irradiation atmosphere was 80 ppm. The thickness of the hard coat layer (8) after curing was 2 μm.

  A disk sample was produced as described above.

[Example 2]
A disk sample was produced in the same manner as in Example 1 except that the electron beam irradiation dose was 20 kGy in the hard coat layer curing step.

[Example 3]
A disk sample was produced in the same manner as in Example 1 except that the electron beam irradiation dose was 40 kGy in the hard coat layer curing step.

[Example 4]
A disk sample was produced in the same manner as in Example 1 except that the electron beam irradiation dose was set to 100 kGy in the hard coat layer curing step.

[Comparative Example 1]
A disk sample was produced in the same manner as in Example 1 except that the electron beam irradiation after ultraviolet irradiation was not performed in the hard coat layer curing step.

[Comparative Example 2]
A disk sample was produced in the same manner as in Example 1 except that the hard coat layer curing step was performed as follows.
The uncured hard coat layer was irradiated with an electron beam under a nitrogen stream. Using an electron beam irradiation apparatus Min-EB (manufactured by Toyo Ink Manufacturing Co., Ltd.), the electron beam acceleration voltage was 50 kV, and the irradiation dose was 20 kGy. Thereafter, the light transmitting layer (7) and the hard coat layer (8) are completely cured by irradiating with ultraviolet rays at an irradiation intensity of 280 W / cm, a distance from the lamp of 11 cm, and an integrated light quantity of 3000 mJ / cm ² under a nitrogen stream. I let you. The oxygen concentration in the ultraviolet irradiation and electron beam irradiation atmosphere was 80 ppm. The thickness of the hard coat layer (8) after curing was 2 μm.

[Comparative Example 3]
A disk sample was produced in the same manner as in Example 1 except that the hard coat layer curing step was performed as follows.
The uncured hard coat layer was irradiated with an electron beam under a nitrogen stream. Using an electron beam irradiation apparatus Min-EB (manufactured by Toyo Ink Manufacturing Co., Ltd.), the electron beam acceleration voltage was 50 kV and the irradiation dose was 100 kGy. Thereafter, the light transmitting layer (7) and the hard coat layer (8) are completely cured by irradiating with ultraviolet rays at an irradiation intensity of 280 W / cm, a distance from the lamp of 11 cm, and an integrated light quantity of 3000 mJ / cm ² under a nitrogen stream. I let you. The oxygen concentration in the ultraviolet irradiation and electron beam irradiation atmosphere was 80 ppm. The thickness of the hard coat layer (8) after curing was 2 μm.

[Comparative Example 4]
A disk sample was produced in the same manner as in Example 1 except that the hard coat layer curing step was performed as follows.
The uncured hard coat layer was irradiated with an electron beam under a nitrogen stream. Using an electron beam irradiation apparatus Min-EB (manufactured by Toyo Ink Manufacturing Co., Ltd.), the electron beam acceleration voltage was 50 kV and the irradiation dose was 100 kGy. The oxygen concentration in the electron beam irradiation atmosphere was 80 ppm.

[Measurement method of electron beam irradiation dose]
Prior to each of the above examples and comparative examples, the electron beam irradiation dose in the case of using the electron beam irradiation apparatus Min-EB was obtained in advance as follows.
The electron beam irradiation dose was measured using a RADIACHROMIC READER (RCD) manufactured by FAR WEST Technology, USA, using an RCD film manufactured by the same company, product number FWT60-810, and a film thickness of 10 μm. This film is generally used as an electron beam irradiation dose measuring film, and measures an electron beam absorbed dose from the amount of coloring of the film. The operation procedure is as follows. This operation procedure is described in “Ultra-low energy electron beam irradiation and its characteristics”, Radiation and Industry, 77 (1998).

-Turn on the RCD before measurement and allow a predetermined time (about 15 to 60 minutes) until the RCD stabilizes.
Set the RCD wavelength dial to 600 nm (for film thickness 10 μm).
・ Set the RCD cell (holder) to the full light transmission state and perform zero point correction.
-Make the RCD cell (holder) opaque and make 100% correction.
-Cut an unirradiated film into a 1 cm x 1 cm square, put it in a cell, and set it in a reader to perform measurement. This is the blank value.
The irradiated measurement film irradiated using the electron beam irradiation apparatus Min-EB is cut into a 1 cm × 1 cm square, put into a cell, and set in a reader for measurement. Thereby, an OD value (absorbance) is obtained.
-The electron beam absorbed dose of the film can be obtained as follows.
Absorbed dose = 0.333 × (t / 0.01) ^1.219
Where t = (OD value) − (blank value)

[Evaluation of disk sample]
The performance test shown below was performed on each disk sample produced in Examples 1-4 and Comparative Examples 1-4.

(Evaluation of antifouling properties and durability)
The contact angle of the hard coat surface of each disk sample was measured. Pure water is dropped onto the hard coat surface of each disk sample in an atmosphere of a temperature of 25 ° C. and a relative humidity of 50%, and a contact angle meter CA-D (trade name) manufactured by Kyowa Interface Science Co., Ltd. is used. The static contact angle of pure water was measured according to the sessile drop method defined in R3257-1999. First, the initial contact angle (a) was measured.

Next, as an evaluation of antifouling durability, the contact angle (b) after acetone rubbing was measured. Regarding the contact angle (b) after the acetone rubbing, a nonwoven fabric (Asahi Kasei Kogyo Co., Ltd., Bencott Lint Free CT-8) was impregnated with acetone, and this was hardened for each disk sample at a load of 9.8 N / cm ² . The surface was rubbed by pressing against the coat surface and sliding 100 times. Thereafter, the contact angle was measured under the same conditions as described above.

  This rubbing test with an acetone-impregnated nonwoven fabric is a severe test for confirming the fixation of the lubricating substance (A) present on the hard coat surface of the disk sample. If the contact angle (b) after acetone rubbing is not lowered from the initial contact angle (a), the disc sample is very reliable even when used repeatedly over a long period of time.

(Coefficient of friction)
According to the method schematically shown in FIG. 5, the coefficient of friction of the hard coat surface of the disk sample (initial one) was measured. Referring to FIG. 5, the optical disk sample (1) was placed on the spindle motor (21) so that the hard coat (8) surface was up. A non-woven fabric (22) (Bencott Lint Free CT-8, manufactured by Asahi Kasei Kogyo Co., Ltd.) cut into a strip shape having a width of 20 mm and a length of 100 mm was placed on the hard coat (8) surface of the optical disk, and then the non-woven fabric (22 On one end (22a), a weight (30) having a circular bottom with a diameter of 20 mm and a weight of 30 g was placed and a load of 0.1 N / cm ² was applied. At this time, the weight (24) is positioned approximately 40 mm in the radial direction from the center of the disk, and the longitudinal direction of the nonwoven fabric (22) is the radial direction connecting the center of the disk and the position of the weight (24). And set to be vertical. The other end (22b) of the nonwoven fabric (22) was fixed to the transducer (23), and the optical disk (1) was rotated at a rotational speed of 670 rpm in this state. The friction force generated in the nonwoven fabric (22) was detected by the transducer (23), and the friction coefficient was measured.

  The above measurement results are shown in Table 1. In the curing step of Table 1, UV represents ultraviolet irradiation, and EB represents electron beam irradiation.

  From Table 1, all of the disk samples of Examples 1 to 4 were very excellent in antifouling property and durability. In all of the disk samples of Comparative Examples 1 to 4, the contact angle (b) after acetone rubbing was lower than the initial contact angle (a) as compared with Examples 1 to 4. In Example 2 and Comparative Example 2, a large difference was observed in the decrease in the contact angle (b) despite the same ultraviolet ray irradiation amount and the same electron beam irradiation amount.

  In the above embodiment, an example of manufacturing a phase change optical disk has been shown. However, the present invention is applied not only to a phase change type optical disc but also to a read-only optical disc and a write once optical disc. Further, the present invention is applied not only to the optical disc but also to the application of a protective layer or hard coat layer to various other object surfaces. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.

It is a schematic sectional drawing which shows an example of the laminated constitution of the optical disk manufactured in this invention. It is a schematic sectional drawing which shows an example of the laminated constitution of the optical disk manufactured in this invention. It is a schematic sectional drawing which shows the other layer structural example of the optical disk manufactured in this invention. It is a schematic sectional drawing which shows the other layer structural example of the optical disk manufactured in this invention. It is a figure for demonstrating the measuring method of the friction coefficient of an optical disk.

Explanation of symbols

(20): Support base
(3): Reflective layer
(52): Second dielectric layer
(4): Recording layer
(51): First dielectric layer
(7): Light transmission layer
(8): Protective layer (hard coat layer)

Claims (9)

A composition for a protective layer containing an active energy ray-reactive silicone compound and / or a fluorine compound (A) and an active energy ray-curable compound (B) is applied onto a target object to which a protective layer is to be applied. And an application process for forming an uncured protective layer;
A method for forming a protective layer on a target object, comprising: irradiating an uncured protective layer with ultraviolet rays and then irradiating an electron beam to form a cured protective layer. An optical information medium having a film body composed of one or more layers including at least an information layer on a support substrate, and having a protective layer on at least one of the support substrate side and the film body side A manufacturing method comprising:
An active energy ray-reactive silicone compound and / or fluorine compound (A) and an active energy ray-curable compound (B) on at least one of the support substrate side and the film body side. An application step of forming an uncured protective layer by applying a protective layer composition comprising:
And a curing step of irradiating an uncured protective layer with ultraviolet rays and then irradiating an electron beam to form a cured protective layer. The optical information medium according to claim 2, comprising 0.01 part by weight or more and 3 parts by weight or less of the silicone compound and / or the fluorine compound (A) with respect to 100 parts by weight of the nonvolatile content in the composition for the protective layer. Manufacturing method. The silicone compound and / or fluorine compound (A) contained in the protective layer composition is a group comprising a silicone group and / or a fluorine group, a (meth) acryloyl group, a vinyl group, and a mercapto group. The method for producing an optical information medium according to claim 2, wherein the method has at least one reactive group selected from the group consisting of: The active energy ray-curable compound (B) contained in the protective layer composition has at least one reactive group selected from the group consisting of a (meth) acryloyl group, a vinyl group and a mercapto group. Item 5. The method for producing an optical information medium according to any one of Items 2 to 4. The method for producing an optical information medium according to any one of claims 2 to 5, wherein the protective layer composition further comprises inorganic fine particles (C) having an average particle diameter of 100 nm or less. The composition for a protective layer contains 5 parts by weight or more and 500 parts by weight or less of the inorganic fine particles (C) with respect to 100 parts by weight of the active energy ray-curable compound (B). Method. The method for producing an optical information medium according to any one of claims 2 to 7, wherein in the curing step, an acceleration voltage of the electron beam in electron beam irradiation is 20 to 100 kV. The method for producing an optical information medium according to claim 2, wherein the cured protective layer has a thickness of 0.5 μm or more and 5 μm or less.

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