JP2009238314A - Sheet for multilayer optical recording medium, multilayer structure for optical recording medium, and multilayer optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for a multilayer optical recording medium for manufacturing the multilayer optical recording medium having high thickness accuracy of each layer and the whole layer and capable of reducing the occurrence of crosstalk by suppressing transfer of a dye material which constitutes an optical recording layer to other layers, to provide a multilayer structure for the optical recording medium formed by using the sheet and to provide the multilayer optical recording medium having the multilayer structure and such characteristics. <P>SOLUTION: The sheet for the multilayer optical recording medium for manufacturing the multilayer optical recording medium having a repetitive structure, in which a plurality of optical recording mediums are layered, has a structure where dye material thin films and adhesive layers are layered and an adhesive which constitutes the adhesive layers has -10 to 100°C glass transition temperature Tg. In the multilayer structure for the optical recording medium formed by using the sheet, the optical recording layers composed of the dye material thin films and the adhesive layers are alternately layered. The multilayer optical recording medium has the multilayer structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multilayer optical recording medium sheet, a multilayer structure for an optical recording medium, and a multilayer optical recording medium having the same. More specifically, the present invention relates to a multilayer optical recording medium that has high thickness accuracy of each layer and the entire layer, and can suppress the occurrence of crosstalk by suppressing the transfer of the dye material constituting the optical recording layer to the other layer. The present invention relates to a multilayer optical recording medium sheet for production, an optical recording medium multilayer structure formed using the sheet, and a multilayer optical recording medium having the above-described characteristics, which includes the multilayer structure.

In recent years, multilayer optical recording media using multiphoton absorbing materials have been proposed for the purpose of increasing the density of recorded information in optical recording media. In order to reduce crosstalk in the multilayer optical recording medium, a configuration in which a non-optical recording layer is interposed between the optical recording layer and the optical recording layer has been proposed (see, for example, Patent Documents 1 and 2). However, in the case of such a laminated structure, a method of forming each layer by a spin coating method and laminating is usually used, but there is a problem that it is difficult to increase the area and the material is limited.
As a method for solving such a problem, the present inventors invented a method of laminating an optical recording layer thin film sheet composed of a multiphoton absorbing material and a non-optical recording layer thin film sheet composed of a pressure sensitive adhesive. (For example, refer to Patent Document 3). According to the manufacturing method using these sheets, a multilayer optical recording medium can be easily manufactured in a large area.
However, in this case, depending on the type of the multiphoton absorbing material and the pressure sensitive adhesive, or the environmental conditions, the multiphoton absorbing material may be disposed on the non-optical recording layer thin film sheet side made of the pressure sensitive adhesive over time. There are problems such as migration, diffusion, and the possibility of crosstalk.
JP-A-11-250496 JP 2000-67464 A JP 2005-209328 A

  Under such circumstances, the present invention has high thickness accuracy of each layer and the whole layer, and can suppress the occurrence of crosstalk by suppressing the migration of the dye material constituting the optical recording layer to the other layer. A multilayer optical recording medium sheet for producing a multilayer optical recording medium, a multilayer structure for an optical recording medium formed using the sheet, and a multilayer optical recording medium having the above-described characteristics, comprising the multilayer structure It is intended to provide.

As a result of intensive studies to achieve the above object, the present inventors have a structure in which a dye material thin film and an adhesive layer are laminated, and the glass transition of the adhesive constituting the adhesive layer. It has been found that the object can be achieved by a multilayer optical recording medium sheet having a temperature Tg in a specific range. The present invention has been completed based on such findings.
That is, the present invention
[1] A sheet for producing a multilayer optical recording medium having a repeated structure in which a plurality of optical recording layers are laminated, having a structure in which a dye material thin film and an adhesive layer are laminated, and the above adhesion A sheet for multilayer optical recording media, wherein the adhesive constituting the agent layer has a glass transition temperature Tg of −10 to 100 ° C .;
[2] The multilayer optical recording medium sheet according to the above [1], wherein the lamination temperature when producing the multilayer optical recording medium is 10 ° C. or higher and 120 ° C. or lower than the Tg of the adhesive;
[3] The multilayer optical recording medium sheet according to the above [1] or [2], wherein the adhesive strength of the adhesive is 500 to 50,000 mN / 25 cm,
[4] The multilayer optical recording medium sheet according to any one of [1] to [3], wherein the dye material constituting the dye material thin film contains a multiphoton absorbing material,
[5] It is formed using the sheet according to any one of [1] to [4] above, and an optical recording layer made of a dye material thin film and an adhesive layer are alternately laminated. A multilayer structure for optical recording media,
[6] The multilayer structure for optical recording media according to the above item [5], in which positional information is provided, and [7] the multilayer structure according to the item [5] or [6]. Multilayer optical recording medium,
Is to provide.

  According to the present invention, a multilayer optical recording medium is manufactured that has high thickness accuracy of each layer and the whole layer, and can suppress the occurrence of crosstalk by suppressing the migration of the dye material constituting the optical recording layer to the other layer. Therefore, it is possible to provide a multilayer optical recording medium sheet, a multilayer structure for an optical recording medium formed using the sheet, and a multilayer optical recording medium having the above-described characteristics, which includes the multilayer structure.

First, the multilayer optical recording medium sheet of the present invention (hereinafter sometimes simply referred to as a sheet) will be described.
[Multilayer optical recording medium sheet]
The multilayer optical recording medium sheet of the present invention is a sheet for producing a multilayer optical recording medium having a repeating structure in which a plurality of optical recording layers are laminated, in which a dye material thin film and an adhesive layer are laminated. The glass transition temperature Tg of the adhesive which has a structure and constitutes the adhesive layer is -10 to 100 ° C.

(Dye material thin film)
In the sheet of the present invention, the material constituting the dye material thin film that is an optical recording layer is not particularly limited as long as it contains a multiphoton absorbing material, and is a constituent material of an optical recording layer in a conventional optical recording medium. Any one of materials known as can be appropriately selected and used. A multiphoton absorbing material means a compound having the property of simultaneously absorbing two or more photons and transitioning to an excited state. Among these, from the viewpoint of obtaining recording sensitivity sufficient for practical use, those containing a two-photon absorbing material having a two-photon absorption cross-sectional area of 0.1 GM or more are preferable, and those containing a two-photon absorbing material of 100 GM or more are particularly preferable. preferable. As such a material, for example, a multiphoton absorbing material constituted alone, or a multiphoton absorbing material, for example, and other reactive compounds that change due to energy transfer from the excited multiphoton absorbing material. You may comprise with the material comprised by these, and the material which mix | blended these with the matrix as needed. The “GM” means 10 ⁻⁵⁰ cm ⁴ · s · molecule ⁻¹ · photon ⁻¹ .
The material constituting the matrix may be an inorganic material or an organic material. However, from the viewpoint of ease of production of the sheet of the present invention and many choices of materials, an organic polymer material is used. Is preferred. The polymer material may be a homopolymer or a copolymer, and there are no particular restrictions on the type of monomer, molecular weight, polymerization form, and the like.

<Polymer material>
Specific examples of the polymer material include various polyethylene, ethylene / 1-butene copolymer, ethylene / 4-methyl-1-pentene copolymer, ethylene / 1-hexene copolymer, polypropylene, ethylene / propylene copolymer. Polymer, propylene / 1-butene copolymer, poly 1-butene, 1-butene / 4-methyl-1-pentene copolymer, poly-4-methyl-1-pentene, poly-3-methyl-1-butene, Polyolefins such as ethylene / cyclic olefin copolymer, cyclic olefin resin, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer or metal salt thereof, polymethyl methacrylate, alicyclic acrylic resin, etc. Polyester resins such as (meth) acrylate, polyethylene terephthalate, polyethylene naphthalate, Fluorine resins such as fluoroethylene and perfluoroalkenyl vinyl ether polymers, polystyrene, polyvinyl alcohol, polycarbonate, polyphenylene sulfide, polyethersulfone, polyimide, polyphenylene oxide, olefin / N-substituted maleimide copolymers, allyl carbonate resins, epoxy acrylates Examples thereof include resins and urethane acrylate resins. These polymer materials may be used alone or in combination of two or more.

<Multiphoton absorbing material>
The multiphoton absorbing material may be chemically bonded to the matrix as a main chain or side chain component, or may be simply dispersed or dissolved in the matrix. The multiphoton absorbing material is not particularly limited, and various compounds can be used. Examples of the multiphoton absorbing material include cyanine dyes, styryl dyes, pyrylium dyes, thiapyrylium dyes, merocyanine dyes, arylidene dyes, oxonol dyes, squalium dyes, azurenium dyes, coumarin dyes, pyran dyes, quinone dyes, anthraquinone dyes, Chilephenylmethane dye, diphenylmethane dye, xanthene dye, thioxanthene dye, phenothiazine dye, azo dye, azomethine dye, fluorenone dye, diarylethene dye, spiropyran dye, fulgide dye, perylene dye, polyene dye, diphenylamine dye, quinacdrine dye, azulenium dye Porphyrin dyes, phthalocyanine dyes, styrene dyes, phenylene vinylene dyes, triphenylamine dyes, carbazole dyes, etc. It is.
In the present invention, the multiphoton absorbing material is not particularly limited as to the molecular weight, but preferably has a molecular weight of 600 or more. When the molecular weight is 600 or more, the migration of the multiphoton absorbing material to the adhesive layer can be suppressed particularly under wet heat. The upper limit of the molecular weight is not particularly limited, but the number average molecular weight Mn is usually about 100,000.
Such a high molecular weight multiphoton absorbing material can be obtained, for example, by chemically bonding to the above-described matrix as a main chain or side chain component.
The number average molecular weight is a value in terms of polystyrene measured by a gel permeation chromatography method (GPC method).

As a recording method using such a multiphoton absorbing compound, for example, a material that is isomerized by light, such as an azo group, a C═C group, or a C═N group-containing compound, or a (meth) acrylate compound For example, a material that causes a polymerization reaction by light, a material that causes a reversible structural change by light, such as an organic photochromic material, a method that reads refractive index modulation using an organic refractory material in which charge distribution is caused by light, A method of reading fluorescence using a material whose fluorescence characteristics change, a combination of a material that generates acid by light and an acid coloring dye, or a combination of a decoloring agent and a decoloring dye to perform absorption rate modulation or refractive index modulation. Examples include reading methods. In these recording methods, the multiphoton absorbing compound itself may have such photoreactivity, or from the multiphoton absorbing compound excited by multiphoton absorption to another reactive compound. The reaction may be caused by energy transfer.
In the sheet of the present invention, the thickness of the dye material thin film is not particularly limited, but is usually about 0.04 to 50 μm, preferably 0.05 to 10 μm.

(Adhesive layer)
In the sheet of the present invention, as the adhesive constituting the adhesive layer, an adhesive having a glass transition temperature Tg in the range of −10 to 100 ° C. can be used. When the Tg is less than −10 ° C., particularly when the molecular weight of the multiphoton absorbing material is less than 600, the transition of the multiphoton absorbing material to the adhesive layer cannot be sufficiently suppressed, and the multiphoton It is inevitable that the degree of freedom of selection of the absorbent material is limited. On the other hand, when the Tg exceeds 100 ° C., the adhesive strength of the adhesive layer is remarkably lowered, and the function as the adhesive layer cannot be exhibited. Preferred Tg is in the range of -5 to 90 ° C.
As the adhesive in the present invention, an acrylic adhesive is preferable from the viewpoint of optical use from the viewpoint of tackiness.
As this acrylic adhesive, for example, an adhesive containing a (meth) acrylic ester copolymer and a crosslinking agent can be used.

<(Meth) acrylic ester copolymer>
As the (meth) acrylic acid ester-based copolymer, (meth) acrylic acid ester having 1 to 20 carbon atoms in the alkyl group of the ester portion, a monomer having a functional group having active hydrogen, and other optionally used The copolymer with the monomer of this can be mentioned preferably.
Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms in the alkyl group of the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl (meth) acrylate. , N-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl Examples include (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

On the other hand, examples of monomers having a functional group having active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth). Acrylate, 3-hydroxybutyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 4-hydroxybutyl (meth) acrylate, monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) ) Monoalkylaminoalkyl (meth) acrylates such as acrylate and monoethylaminopropyl (meth) acrylate; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, citraconic acid, etc. And the like. These monomers may be used independently and may be used in combination of 2 or more type.
In the (meth) acrylic acid ester copolymer, monomers such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate and the like can be used to increase Tg. The total monomer content is preferably 30 to 90% by mass.

  Examples of other monomers used as desired include vinyl esters such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene, α -Styrene monomers such as methylstyrene; Diene monomers such as butadiene, isoprene and chloroprene; Nitrile monomers such as acrylonitrile and methacrylonitrile; Acrylamides such as acrylamide, N-methylacrylamide and N, N-dimethylacrylamide Can be mentioned. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester-based copolymer is not particularly limited as to its copolymerization form, and may be any of random, block, and graft copolymers. The molecular weight is preferably in the range of 300,000 to 2,000,000 in terms of weight average molecular weight.
In addition, the said weight average molecular weight is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.
In the present invention, this (meth) acrylic acid ester copolymer may be used alone or in combination of two or more.

<Crosslinking agent>
There are no particular restrictions on the crosslinking agent in the acrylic adhesive, and those conventionally used as crosslinking agents in acrylic adhesives, such as polyisocyanate compounds, epoxy compounds, aziridine compounds, melamine resins, urea resins, dialdehydes. , Methylol polymer, metal chelate compound, metal alkoxide, metal salt, etc., can be selected as appropriate, but the light transmittance hardly changes due to discoloration (yellowing) of the adhesive layer, and laser irradiation An alicyclic polyisocyanate compound, an aliphatic polyisocyanate compound, an alicyclic epoxy compound, an aliphatic epoxy compound, a metal chelate compound, or an aliphatic aziridine compound that is unlikely to undergo alteration due to the above is preferable.
There is no restriction | limiting in particular as a metal chelate compound, Arbitrary things can be suitably selected from a well-known compound as a metal chelate type compound in an acrylic adhesive. The metal chelate compounds include chelate compounds whose metal atoms are aluminum, zirconium, titanium, zinc, iron, tin, etc., but aluminum chelate compounds are preferred from the viewpoint of performance.

  Examples of the alicyclic polyisocyanate compounds and aliphatic polyisocyanate compounds include isophorone diisocyanate, bicycloheptane triisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, Hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and their biurets, isocyanurates, and ethylene glycol, propylene glycol, neopentyl glycol, trimethylol The adduct body etc. which are a reaction material with low molecular active hydrogen containing compounds, such as a propane and a castor oil, can be mentioned.

  Examples of alicyclic epoxy compounds and aliphatic epoxy compounds include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, hydrogen Examples thereof include added bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol glycidyl ester, adipic acid glycidyl ester, and sebacic acid glycidyl ester.

  Examples of the aluminum chelate compound include diisopropoxy aluminum monooleyl acetoacetate, monoisopropoxy aluminum bis oleyl acetoacetate, monoisopropoxy aluminum monooleate monoethyl acetoacetate, diisopropoxy aluminum monolauryl acetoacetate, diisopropoxy aluminum Monostearyl acetoacetate, diisopropoxyaluminum monoisostearyl acetoacetate, monoisopropoxyaluminum mono-N-lauroyl-β-alanate monolauryl acetoacetate, aluminum trisacetylacetonate, monoacetylacetonate aluminum bis (isobutylacetoacetate ) Chelate, monoacetylacetonate aluminum bis (2-ethylhexyl acetoacetate) chelate, monoacetylacetonate aluminum bis (dodecyl acetoacetate) chelate, monoacetylacetonate aluminum bis (oleyl acetoacetate) chelate, and the like.

  There is no restriction | limiting in particular as an aliphatic aziridine type compound, Arbitrary things can be suitably selected from a well-known compound as an aliphatic aziridine type compound in an acrylic adhesive. Examples of the aliphatic aziridine compounds include trimethylolpropane tri (2-methyl-1-aziridinepropionate), tetramethylolmethane-tri-β-aziridinylpropionate, and 2,2′-bishydroxymethylbutanol. -Tris [3- (1-aziridinyl) propionate], 1,6-hexamethylenediethylene urea and the like.

In the present invention, the above alicyclic polyisocyanate compound, aliphatic polyisocyanate compound, alicyclic epoxy compound, aliphatic epoxy compound, metal chelate compound and aziridine compound are used alone. You may use and may use it in combination of 2 or more type. Moreover, the content is 0.01-5.0 mass parts normally with respect to 100 mass parts of said (meth) acrylic acid ester-type copolymers from a viewpoint of the performance as an adhesive agent, Preferably it is 0.05-. It is selected in the range of 3.0 parts by mass, more preferably 0.1 to 1.0 parts by mass.
If necessary, a tackifier, an antioxidant, an ultraviolet absorber, a light stabilizer, a softener, a filler, and the like can be added to the adhesive as long as the effects of the present invention are not impaired.
Although there is no restriction | limiting in particular in the thickness of the adhesive bond layer in the sheet | seat of this invention, Usually, about 1-100 micrometers, Preferably it is 2-30 micrometers.

In the sheet of the present invention, if necessary, position information having irregularities on the surface as recording pits and / or grooves in order to provide position information inside the transparent resin layer for reinforcing the sheet or in the multilayer optical recording medium An application layer, an optical waveguide layer, a reflective layer, a dielectric layer, and the like may be present.
In this case, for example, the transparent resin layer can be provided between the dye material thin film and the adhesive layer or on the dye material thin film, and the position information providing layer is an adhesive from the viewpoint of convenience of forming it. It is advantageous to provide the outermost layer on the side opposite to the layer.

(Transparent resin layer)
In the sheet of the present invention, if desired, the sheet is reinforced by providing a transparent resin layer. As a result, when the sheet is laminated to produce the multilayer structure or multilayer optical recording medium of the present invention, Wrinkles can be suppressed from occurring in the dye material thin film layer.
The material of the transparent resin layer is not particularly limited as long as it is transparent and can effectively exhibit reinforcing properties and does not impair the optical properties of the sheet of the present invention. Examples of such materials include triacetyl cellulose, polycarbonate resin, cycloolefin resin, modified acrylic resin, cured photopolymerizable oligomer, polyvinyl alcohol, polyimide, polyetherimide, polysulfone, polyethersulfone, and polyarylate. Polyesters such as polyethylene terephthalate can be mentioned. Among these, those having low birefringence are preferable, and specifically, triacetyl cellulose, cycloolefin resin, polycarbonate resin and the like are preferable.
In the present invention, the transparent resin layer may be formed using the resin material in the form of a film, or may be formed by a coating method using a coating liquid containing the resin material.

In the present invention, the transparent resin layer made of the above material has a glass transition temperature of preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and still more preferably, from the viewpoint of sheet reinforcing effect and reliability as an optical recording medium. Is 70 to 250 ° C., and the elongation at break is preferably less than 300%, more preferably 250% or less, and still more preferably 1 to 200%. The thickness is preferably 1 to 100 μm, more preferably 2 to 90 μm, and still more preferably 2 to 2 μm from the viewpoint of having a reinforcing effect and effectively preventing wrinkles and obtaining a practical recording density. 80 μm.
The glass transition temperature of this transparent resin layer is in the temperature range of −80 ° C. to 250 ° C. using an input-compensated differential scanning calorimetry apparatus [manufactured by Perkin Elmer, apparatus name “Pyrisl DSG”] according to JIS K 7121. Thus, the glass transition temperature (Tg) is measured by measuring the temperature at which the external glass transition starts. The elongation at break is the tensile fracture strain when the sample measured according to JIS K 7161 and JIS K 7127 does not have a yield point, and the tensile fracture nominal strain when the sample has a yield point. It is a value.

  The transparent resin layer may be subjected to a surface treatment by an oxidation method or a concavo-convex method, if desired, for the purpose of improving adhesion with a layer provided thereon. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and examples of the unevenness method include a sand blast method, a solvent, and the like. Treatment methods and the like. These surface treatment methods are appropriately selected depending on the type of the transparent resin layer, but in general, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.

(Location information layer)
The position information imparting layer that can be provided as desired in the sheet of the present invention is not particularly limited in its formation method. For example, an energy ray curable transfer layer is provided on the outermost layer on the side opposite to the adhesive layer. The recording pits and / or grooves can be formed by transferring the shape of a stamper having irregularities on the surface and then curing it by irradiating energy rays. The energy ray curable transfer layer can be formed using an energy ray curable polymer material.
In the present invention, the energy beam curable polymer material refers to a polymer material that has an energy quantum in an electromagnetic wave or a charged particle beam, that is, a polymer material that is cross-linked by irradiation with ultraviolet rays or electron beams.
Examples of the energy beam curable polymer material used in the present invention include (1) a polymer material containing an acrylic polymer, an energy beam curable polymerizable oligomer and / or a polymerizable monomer, and, if desired, a photopolymerization initiator, (2) An acrylic polymer in which an energy ray-curable functional group having a polymerizable unsaturated group in the side chain is introduced, and a polymer material containing a photopolymerization initiator if desired.
In the polymer material of (1), the acrylic polymer has a (meth) acrylic acid ester having an alkyl group of 1 to 20 carbon atoms in the ester moiety and a functional group having an active hydrogen as required. Preferred examples include monomers and copolymers with other monomers, that is, (meth) acrylic ester copolymers.

For the (meth) acrylic acid ester having 1 to 20 carbon atoms in the alkyl group of the ester moiety, the monomer having a functional group having active hydrogen, and other monomers, in the description of the acrylic adhesive described above As shown.
In the (meth) acrylic acid ester-based copolymer, the (meth) acrylic acid ester component is usually contained in an amount of about 5 to 100% by mass, preferably 50 to 95% by mass, and a monomer having a functional group having active hydrogen. The component is usually contained in an amount of about 0 to 95% by mass, preferably 5 to 50% by mass. In addition, other monomer components can be contained in an amount of about 0 to 30% by mass.
In the polymer material, the (meth) acrylic ester copolymer used as the acrylic polymer is not particularly limited as to the form of copolymerization, and may be any of random, block, and graft copolymers. Good. The molecular weight is preferably 50,000 or more in terms of weight average molecular weight.
In addition, the said weight average molecular weight is the value of standard polymethylmethacrylate conversion measured by the gel permeation chromatography (GPC) method.
In the present invention, this (meth) acrylic acid ester copolymer may be used alone or in combination of two or more.

Examples of the energy ray curable polymerizable oligomer include polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, and silicone acrylate. Here, as the polyester acrylate oligomer, for example, by esterifying hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The epoxy acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. A carboxyl-modified epoxy acrylate oligomer obtained by partially modifying this epoxy acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol with polyisocyanate with (meth) acrylic acid. It can be obtained by esterifying the hydroxyl group of ether polyol with (meth) acrylic acid.
The weight average molecular weight of the polymerizable oligomer is a value in terms of standard polymethyl methacrylate measured by GPC method, preferably 500 to 100,000, more preferably 1,000 to 70,000, and still more preferably 3,000 to It is selected in the range of 40,000.
This polymerizable oligomer may be used individually by 1 type, and may be used in combination of 2 or more type.

On the other hand, examples of the energy curable polymerizable monomer include monofunctional acrylates such as cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) Acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate Allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified Dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, And polyfunctional acrylates such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These polymerizable monomers may be used alone or in combination of two or more.
The compounding quantity of these polymerizable oligomers or polymerizable monomers is usually about 3 to 400 parts by mass with respect to 100 parts by mass of the solid content of the (meth) acrylic acid ester copolymer.

Moreover, although an ultraviolet-ray or an electron beam is normally irradiated as an energy ray, when irradiating an ultraviolet-ray, a photoinitiator can be used. Examples of this photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl Ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-fe Rubenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligo [2-hydroxy-2-methyl-1- [4- (1-propenyl) ) Phenyl] propanone] and the like. These may be used alone or in combination of two or more.
A compounding quantity is 0.1-10 mass parts normally with respect to 100 mass parts of solid content of the above-mentioned energy ray hardening-type polymeric material.

Next, in the polymer material of (2), an acrylic polymer obtained by introducing an energy ray-curable functional group having a radical polymerizable unsaturated group in the side chain is, for example, the high polymer of (1) described above. An active site such as —COOH, —NCO, epoxy group, —OH, —NH ₂ is introduced into the polymer chain of the acrylic polymer described in the molecular material, and a compound having this active site and a radically polymerizable unsaturated group is obtained. Examples thereof include those obtained by reacting and introducing an energy ray-curable functional group having a radical polymerizable unsaturated group into the side chain of the acrylic polymer.
In order to introduce the active site into the acrylic polymer, a functional group such as —COOH, —NCO, epoxy group, —OH, —NH ₂ , and radical polymerizable A monomer or oligomer having a saturated group may be present in the reaction system.
Specifically, when the -COOH group is introduced when producing the acrylic polymer described in the polymer material of (1) above, (N) group is introduced with (meth) acrylic acid or the like. In the case of introducing 2- (meth) acryloyloxyethyl isocyanate, in the case of introducing an epoxy group, glycidyl (meth) acrylate or the like, in the case of introducing an -OH group, 2-hydroxyethyl (meta ) Acrylate, 1,6-hexanediol mono (meth) acrylate, and the like, and N-methyl (meth) acrylamide or the like may be used when the —NH ₂ group is introduced.

Examples of the compound having a radical polymerizable unsaturated group to be reacted with these active sites include 2- (meth) acryloxyethyl isocyanate, glycidyl (meth) acrylate, pentaerythritol mono (meth) acrylate, dipentaerythritol mono ( It can be appropriately selected from meth) acrylate, trimethylolpropane mono (meth) acrylate and the like depending on the type of active site.
Thus, an acrylic polymer in which an energy ray-curable functional group having a radically polymerizable unsaturated group is introduced into the side chain of the acrylic polymer via the active site, that is, (meth) acrylic acid An ester copolymer is obtained.
The (meth) acrylic acid ester copolymer introduced with the energy ray-curable functional group preferably has a weight average molecular weight of 100,000 or more, particularly preferably 300,000 or more. In addition, the said weight average molecular weight is the value of standard polymethylmethacrylate conversion measured by GPC method.
Moreover, as a photoinitiator used as needed, the photoinitiator illustrated in description of the polymeric material of the above-mentioned (1) can be used.
In the sheet of the present invention, the thickness of the energy ray curable transfer layer is usually about 2 to 50 μm, preferably 3 to 30 μm.

(Structure of multilayer optical recording medium sheet)
The multilayer optical recording medium sheet of the present invention has, for example, a dye material thin film and an adhesive layer, a transparent resin layer and / or a position information providing layer provided as desired, and the like as described above. Each of the position information providing layer and the adhesive layer is provided on the outermost side. And in order to protect them, a peeling film can be affixed on each surface in the energy-beam curable transfer layer and adhesive layer for forming the said positional information provision layer.
The transparent resin layer provided as desired can be interposed between the adhesive layer and the dye material thin film, or between the dye material thin film and the energy ray curable transfer layer. From the viewpoint of effective expression, it is preferable to interpose between the dye material thin film and the energy ray curable transfer layer.
The release film is not particularly limited, but a release agent layer is formed by applying a release agent such as a silicone resin to a polyolefin film such as a polyethylene film or a polypropylene film, and a polyester film such as the polyolefin film or polyethylene terephthalate. The thing provided is mentioned. Moreover, although there is no restriction | limiting in particular about the thickness of these peeling films, Usually, it is about 20-150 micrometers.

1 to 4 are sectional views showing different examples of the multilayer optical recording medium sheet of the present invention. The multilayer optical recording medium sheet 10 shown in FIG. 1 includes a dye material thin film 1 and an adhesive layer. 2 are laminated, and the first release film 3 and the second release film 4 are adhered to both surfaces thereof.
The multilayer optical recording medium sheet 10a shown in FIG. 2 has a dye material thin film 1 and an adhesive layer 2 laminated thereon, a transparent resin layer 5 further laminated on the dye material thin film 1, and an adhesive. It has the structure where the 2nd peeling film 4 was stuck on the layer 2 side.
A multilayer optical recording medium sheet 10b shown in FIG. 3 has a dye material thin film 1 and an adhesive layer 2 laminated thereon, and has recording pits and / or grooves 6a (position information on the surface) on the dye material thin film 1 side. ) Is provided, and the second release film 4 is adhered to the adhesive layer 2 side.
A multilayer optical recording medium sheet 10c shown in FIG. 4 has a dye material thin film 1 and an adhesive layer 2 laminated thereon, and further has a recording resin pit and / or a transparent resin layer 5 on the surface and a transparent resin layer 5 on the surface. Alternatively, the cured transfer layer 6 provided with the groove 6a (position information) is sequentially laminated, and the second release film 4 is attached to the adhesive layer 2 side.
The transparent resin layer 5 can be replaced with an optical waveguide layer, a reflective layer, a dielectric layer, or the like.

(Preparation of multilayer optical recording medium sheet)
The multilayer optical recording medium sheet 10 shown in FIG. 1 can be produced as follows.
First, on the surface having the peelability of the first release film 3, a coating liquid containing a coloring material thin film forming material at an appropriate concentration is applied to a known application means such as a knife coating method, a roll coating method, a bar coating method. By using a blade coating method, a die coating method, a gravure coating method, or the like, the dried coating film is applied and dried to form a coloring material thin film 1, and the coloring material thin film 1 is first peeled off. A dye material sheet A with the film 3 is prepared.
On the other hand, a pressure-sensitive adhesive coating solution is applied onto the release agent layer of the second release film 4 by a known method such as knife coating, roll coating, bar coating, blade coating, die coating, or gravure coating. By applying and drying so that the thickness of the dry coating film becomes a predetermined thickness, an adhesive layer 2 is formed, and a temporary release film is adhered to the upper surface thereof, thereby attaching a double-sided release film. The agent layer 2 is produced.
Next, the temporary release film of the adhesive layer 2 with a double-sided release film is peeled off and bonded so that the dye material thin film 1 of the dye material sheet A is in contact with the exposed surface of the adhesive layer 2. 1 is obtained.

The multilayer optical recording medium sheet 10a shown in FIG. 2 can be produced as follows.
In the same manner as described above, a coating liquid containing a coloring material thin film forming material at an appropriate concentration is applied to one surface of a resin film to be a transparent resin layer so that the thickness of the dried coating film becomes a predetermined thickness. The pigment material thin film is formed by coating and drying to prepare a pigment material sheet B of the pigment material thin film and the transparent resin layer.
Next, the temporary release film of the adhesive layer 2 with a double-sided release film obtained as described above is peeled off and pasted so that the dye material thin film 1 of the dye material sheet B is in contact with the exposed surface of the adhesive layer 2. By combining, the multilayer optical recording medium sheet 10a shown in FIG. 2 is obtained.

The multilayer optical recording medium sheet 10b shown in FIG. 3 can be produced as follows.
First, a coating solution for forming an energy beam curable transfer layer (hereinafter referred to as a transfer layer forming coating solution) is prepared. This transfer layer forming coating solution may contain a crosslinking agent, a tackifier, an oxidation stabilizer, an ultraviolet absorber, a light stabilizer, a softener, a filler, and the like, if desired, together with the energy ray-curable polymer material described above. It can be prepared by dissolving or dispersing in a suitable solvent to a concentration suitable for coating.
The transfer layer-forming coating solution prepared in this way is applied to the release agent layer of the third release film by a known method such as knife coating, roll coating, bar coating, blade coating, or die coating. Then, a gravure coating method or the like is applied and dried so that the thickness of the dry coating film becomes a predetermined thickness to form an energy ray-curable transfer layer, and a laminate C of the transfer layer and the third release film Is made.
On the other hand, the release film 3 of the multilayer optical recording medium sheet 10 shown in FIG. Next, the energy ray curable transfer layer surface of the laminate C is bonded to the exposed dye material thin film 1 surface, and then the third release film is peeled off to expose the energy ray curable transfer layer surface. Next, after pressing with a rubber roller or the like so that the uneven surface of the stamper with the recording pits and / or groove patterns engraved on the surface is in contact with the energy beam curable transfer layer, the surface is irradiated with energy rays. The transfer layer is cured, and then the stamper is peeled off.
As energy rays, ultraviolet rays or electron beams are usually used. Ultraviolet rays are obtained with a high-pressure mercury lamp, a metal halide lamp, an electrodeless lamp, a xenon lamp or the like, while an electron beam is obtained with an electron beam accelerator or the like. Among these energy rays, ultraviolet rays are particularly preferable. For example, in the case of ultraviolet rays, the irradiation amount of this energy beam is preferably 100 to 5000 mJ / cm ² , and in the case of an electron beam, it is preferably about 10 to 1000 krad.
In this way, the energy ray curable transfer layer becomes the cured transfer layer 6 having the recording pits and / or grooves 6a provided on the surface, and the multilayer optical recording medium sheet 10b shown in FIG. 3 is obtained.

The multilayer optical recording medium sheet 10c shown in FIG. 4 can be produced as follows.
In the same manner as in the production of the multilayer optical recording medium sheet 10b shown in FIG. 3, first, a laminate C of an energy beam curable transfer layer and a third release film is produced.
Next, the energy ray curable transfer layer surface of the laminate C is bonded to the surface of the transparent resin layer 5 of the multilayer optical recording medium sheet 10a shown in FIG. 2 obtained above, and then the third release film. To expose the energy ray curable transfer layer surface. Next, after pressing with a rubber roller or the like so that the uneven surface of the stamper with the recording pits and / or groove patterns engraved on the surface is in contact with the energy beam curable transfer layer, the surface is irradiated with energy rays. The transfer layer is cured, and then the stamper is peeled off to obtain the multilayer optical recording medium sheet 10c shown in FIG.

Next, the multilayer structure for optical recording media of the present invention will be described.
[Multi-layer structure for optical recording media]
The multilayer structure for an optical recording medium of the present invention is a structure in which a plurality of two-layer structural units in which a dye material thin film and an adhesive layer are alternately laminated are formed by using the above-described sheet of the present invention. Or a unit having a three-layer structure in which a cured transfer layer having a recording pit and / or groove on the surface, a dye material thin film, and an adhesive layer are sequentially laminated; A unit with a four-layer structure, in which a transparent resin layer is interposed between the dye material thin film or between the dye material thin film and the adhesive layer, has a structure in which a plurality of layers are laminated via the adhesive layer. ing.
The number of units stacked in the multilayer structure of the present invention is not particularly limited, but is usually about 2 to 200 layers, preferably 3 to 100 layers. A single layer cannot provide a sufficient recording density, and if it exceeds 200 layers, there may be a problem in writing or reading information due to light absorption in each layer or reflection of light between layers.
When laminating using the multilayer optical recording medium sheet of the present invention, the lamination temperature is preferably 10 ° C. or higher and 120 ° C. or lower than the Tg of the adhesive, and 10 ° C. or higher than the Tg. More preferably, the temperature is 115 ° C. or lower. By laminating at a temperature in such a range, it is possible to suppress the deterioration of the pigment material and to easily laminate.

FIG. 5 is a cross-sectional view showing an example of the configuration of the multilayer structure for an optical recording medium of the present invention. The multilayer structure for optical recording medium 20 has recording pits and / or grooves (position information) 6a on the surface (FIG. 5). On the substrate 7 made of a glass plate or a polycarbonate resin provided with a cured transfer layer 6 provided with an adhesive layer and a dye material thin film are alternately laminated in multiple layers to form an adhesive layer 2-1, a dye Material thin film 1-1, Adhesive layer 2-2, Dye material thin film 1-2, Adhesive layer 2-3, Dye material thin film 1-3, .... Adhesive layer 2-n, Dye material thin film 1-n is provided, and the first release film 3 is provided as the uppermost layer.
The multilayer structure 20 for an optical recording medium having such a structure peels off the second release film 4 from, for example, the multilayer optical recording medium sheet 10 of FIG. 1 and exposes the exposed adhesive layer 2 (the adhesive layer in FIG. 5). 2-1) and the cured transfer layer 6 on the substrate 7 face each other, and both are joined. Next, the first release film 3 is peeled from the laminate to expose the dye material thin film 1-1, and the second release film is formed from the dye material thin film 1-1 and another multilayer optical recording medium sheet 10. 4 are peeled off to bond the adhesive layer 2 (in FIG. 5, the adhesive layer 2-2) facing each other. Thereafter, the multilayer structure 20 for optical recording medium in which n layers of dye material thin films are laminated is obtained by sequentially repeating the lamination in the same procedure.
In order to form the cured transfer layer 6 having recording pits and / or grooves (position information) on the surface thereof on the substrate 7 made of a glass plate or polycarbonate resin, the following method can be used. .
First, as described above, an energy ray curable transfer layer forming coating solution is prepared, and this coating solution is applied to the surface of the substrate 7 by a known method such as knife coating, roll coating, bar coating, and the like. The energy ray curable transfer layer is formed by applying and drying the coating film by a coating method, blade coating method, die coating method, gravure coating method or the like so that the thickness of the dried coating film becomes a predetermined thickness. Next, after pressing the surface of the stamper with the recording pits and / or groove patterns on the surface so as to contact the energy ray curable transfer layer with a rubber roller, etc. A method can be used in which the layer is cured and then the stamper is removed.

  The multilayer structure 20 for an optical recording medium thus obtained is provided with the first release film 3 as the uppermost layer. In the present invention, the first release film 3 is peeled off, A light-transmitting protective film or a light-transmitting protective film with a pressure-sensitive adhesive layer can be attached. The light-transmitting protective film is not particularly limited, and can be appropriately selected from those conventionally used as protective films for optical recording media. Although there is no restriction | limiting in particular about the thickness of this protective film, Usually, about 20-600 micrometers, Preferably it is 20-150 micrometers. Moreover, as an adhesive which comprises the said adhesive bond layer, an acrylic adhesive is preferable. The thickness of this adhesive layer is usually about 5 to 60 μm.

The present invention also provides an optical recording medium having the multilayer structure for an optical recording medium.
The information recording / reproducing method for the optical recording medium of the present invention is not particularly limited, and can be appropriately selected from conventionally known methods as the information recording / reproducing method for the multilayer optical recording medium.
The optical recording medium of the present invention has excellent characteristics such as high accuracy in the thickness of each layer and the entire layer, and suppression of migration of the dye material constituting the optical recording layer to other layers, thereby reducing the occurrence of crosstalk. have.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the various characteristics in each example were calculated | required according to the method shown below.
(1) Glass transition temperature of adhesive The temperature of the adhesive obtained in each example was increased / decreased by a differential scanning calorimeter (“DSC Q2000” manufactured by T.A. Instruments Japan, Inc.) at 20 ° C. / Measured in minutes.
(2) Transferability of dye material Non-sticking surface of dye material thin film layer of multilayer optical recording medium composed of release film / dye material thin film layer (0.5 μm) / adhesive layer (7 μm) / release film From the side, the infrared absorption spectrum of the adhesive layer was measured by a diamond ATR method using a Fourier transform infrared spectroscopic analyzer [manufactured by Perkin Elmer, “Spectrum One”].
Next, the multilayer optical recording medium sheet after the measurement of the infrared absorption spectrum was allowed to stand for 24 hours in a moist heat environment at 25 ° C. and 50% RH to promote migration. Thereafter, the infrared absorption spectrum of the adhesive layer was measured from the non-sticking surface side of the dye material thin film layer by a diamond ATR method using a Fourier transform infrared spectroscopic analyzer [manufactured by Perkin Elmer, “Spectrum One”].
In the obtained infrared absorption spectrum, the peak area of 1600 cm ⁻¹ , which is the peak of the benzene ring derived from the dye material, is defined as (B) before the promotion of wet heat, and (A) after the promotion of wet heat, and the absorption peak areas were compared. . If | (A)-(B) | ≦ 0.06, there was no migration, and if | (A)-(B) |> 0.06, it was judged that there was migration.

(3) Crosstalk Polyvinyl alcohol [manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd .: “GOHSENOL T-350”] on the adhesive layer exposed by peeling off the release film on the adhesive layer side of the laminated sample used in the dye material migration test In the confocal optical system using a titanium sapphire femtosecond laser (wavelength 760 nm) as a light source, the dye material thin film layer was irradiated with laser light 25 times. The average intensity of the laser beam was 60 (mW), and the irradiation time was 128 milliseconds. Next, in a confocal laser scanning microscope [manufactured by Carl Zeiss: “LSM5 PASCAL”], using a 633 nm He—Ne laser, observation was performed on the top surface of the irradiated portion on the side of the adhesive layer not in contact with the dye material thin film layer. went. Normally, there should be no recording in this layer, but so-called crosstalk, in which a recording spot is formed when the dye material migrates, is observed. The number of recorded spots observed in the adhesive layer among 25 points was investigated.
(4) Adhesive strength The adhesive strength of the adhesive was measured by peeling off the release film of the adhesive sheet obtained in each example, and then producing a polyethylene terephthalate film [“Cosmo Shine A4100” manufactured by Toyobo Co., Ltd.] (50 μm). After bonding, the release film on the opposite side was peeled off and the adhesive layer was pressure-bonded to a test plate (PMMA plate), and then peeled off by 180 ° according to JIS Z 0327, and the adhesive force was measured as the adhesive force.

<Preparation of dye material sheet>
Production Example 1
As a coloring material, 10 g of 2- [4- (2-chloro-4-nitrophenylazo) -N-ethylphenylamino] ethanol [manufactured by Aldrich: Disperse Red13] was mixed with 45 g of chloroform and 45 g of cyclohexanone to obtain a solid content concentration. A 10% by mass coating solution was prepared.
The coating liquid was applied by a gravure coating method to the release layer surface of a first release film in which an alkyd resin release layer was provided on a 38 μm thick polyethylene terephthalate film substrate, and dried at 110 ° C. for 1 minute. The thickness of the obtained coating film was about 0.5 μm. This sheet is referred to as a pigment material sheet a.

Production Example 2
As a coloring material, 10 g of 1,1-bis [4- [N, N-di (p-tolyl) amino] phenyl] cyclohexane [manufactured by Tokyo Chemical Industry Co., Ltd.] and 90 g of toluene are mixed, and the solid content concentration is 10 mass. % Coating solution was prepared.
The coating liquid was applied by a gravure coating method to the release layer surface of a first release film in which an alkyd resin release layer was provided on a 38 μm thick polyethylene terephthalate film substrate, and dried at 90 ° C. for 1 minute. The thickness of the obtained coating film was about 0.5 μm. This sheet is referred to as a dye material sheet b.

<Preparation of adhesive layer with double-sided release film (adhesive sheet)>
Production Example 3
An aluminum chelate-based cross-linking agent [manufactured by Soken Chemical Co., Ltd., commercial product] to 100 g of ethyl acetate solution (solid content concentration 30% by mass) of n-butyl acrylate / acrylic acid copolymer (composition mass ratio 96/4, weight average molecular weight 500,000) Name “M-5A”, solid content concentration 5 mass%] 8 g was added and stirred until uniform to obtain a coating solution.
Next, the coating liquid was cast on a release agent layer surface of a second release film (thickness 38 μm) in which a silicone release agent layer was provided on a polyethylene terephthalate film using a knife coater, and dried at 90 ° C. for 1 minute. Then, it bonded together using the release agent layer surface and rubber roller of the temporary release film which provided the release agent layer which consists of a silicone resin on the 38 micrometers polyethylene terephthalate film, and it was set as the adhesive sheet A. The obtained adhesive layer had a thickness of about 7.0 μm.

Production Example 4
To 100 g of ethyl acetate solution (solid content concentration 30 mass%) of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 70/20/10, weight average molecular weight 500,000) Isocyanate-based cross-linking agent [manufactured by Toyo Ink Co., Ltd., trade name “BXX4773”, solid content concentration 37.5 mass%] 1 g was added and stirred until uniform to obtain a coating solution. The adhesive sheet B was obtained by the method.

Production Example 5
To 100 g of ethyl acetate solution (solid content concentration 30 mass%) of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 60/30/10, weight average molecular weight 500,000) Isocyanate-based cross-linking agent [manufactured by Toyo Ink Co., Ltd., trade name “BXX4773”, solid content concentration 37.5 mass%] 1 g was added and stirred until uniform to obtain a coating solution. The adhesive sheet C was obtained by the method.

Production Example 6
To 100 g of ethyl acetate solution (solid content concentration 30 mass%) of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 50/40/10, weight average molecular weight 500,000) Isocyanate-based cross-linking agent [manufactured by Toyo Ink Co., Ltd., trade name “BXX4773”, solid content concentration 37.5 mass%] 1 g was added and stirred until uniform to obtain a coating solution. The adhesive sheet D was obtained by the method.

Production Example 7
To 100 g of ethyl acetate solution (solid content concentration 30 mass%) of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 55/35/10, weight average molecular weight 500,000) Isocyanate-based cross-linking agent [manufactured by Toyo Ink Co., Ltd., trade name “BXX4773”, solid content concentration 37.5 mass%] 1 g was added and stirred until uniform to obtain a coating solution. The adhesive sheet E was obtained by the method.

Production Example 8
Aluminum chelate system to 100 g (solid content concentration 30 mass%) of ethyl acetate solution of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 30/60/10, weight average molecular weight 500,000) 8 g of a cross-linking agent [manufactured by Soken Chemical Co., Ltd., trade name “M-5A”, solid content concentration 5 mass%] was added and stirred until uniform to obtain a coating solution. Thus, an adhesive sheet F was obtained.

Production Example 9
Aluminum chelate system to 100 g of ethyl acetate solution (solid content concentration 30 mass%) of n-butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 20/70/10, weight average molecular weight 500,000) 8 g of a cross-linking agent [manufactured by Soken Chemical Co., Ltd., trade name “M-5A”, solid content concentration 5 mass%] was added and stirred until uniform to obtain a coating solution. Thus, an adhesive sheet G was obtained.

Production Example 10
Hexamethylene diisocyanate-based crosslinking agent [Toyo] was added to 100 g (solid content concentration 30% by mass) of ethyl methacrylate solution of methyl methacrylate / 2-hydroxyethyl acrylate copolymer (composition mass ratio: 90/10, weight average molecular weight 500,000). Ink Co., Ltd., trade name “BXX4773”, solid content concentration 37.5 mass%] 1 g was added and stirred until uniform to obtain a coating solution. Got.

Production Example 11
Production Example 3 except that 100 g of a methyl ethyl ketone / methyl isobutyl ketone solution of polymethyl methacrylate [manufactured by Aldrich Co., Ltd.] (solvent mixing ratio: 1/1, solid content concentration 15% by mass) was stirred until it became uniform to obtain a coating solution. An adhesive sheet I was obtained in the same manner as described above.

Example 1
The second release film was peeled off from the adhesive sheet C of Production Example 5 and bonded to the dye material sheet a, followed by pressure bonding at 80 ° C. with two rubber rolls to produce a multilayer optical recording medium sheet. This was used to test the transferability and crosstalk of the dye material.
Moreover, the sheet | seat for confirming adhesive force from the adhesive agent sheet C was produced.
These results are shown in Table 1.

Examples 2-7 and Comparative Examples 1-3
Using the adhesive sheet and the dye material sheet shown in Table 1, the same operations as in Example 1 were performed, and the migration, crosstalk, and adhesive force were evaluated. The results are shown in Table 1.
In Examples 3 and 6, the Tg of the adhesive is the same at 11.0 ° C., but the molecular weight of the dye material is 349 in Example 3 and 627 in Example 6.
When the evaluation sheets of Example 3 and Example 6 were allowed to stand for 24 hours in a wet heat environment of 80 ° C. and 90% RH, the crosstalk was evaluated. As a result, Example 3 was 10/25, and Example 6 0/25.

  As can be seen from Table 1, all of the sheets of the present invention (Examples 1 to 7) have no migration of the dye material and no crosstalk occurs. On the other hand, in Comparative Example 1, sample preparation is impossible, and in the sheets of Comparative Examples 2 and 3, the migration of the dye material is recognized and crosstalk occurs.

  The sheet for multilayer optical recording media of the present invention has a high thickness accuracy of each layer and the whole layer, and can suppress the occurrence of crosstalk by suppressing the migration of the dye material constituting the optical recording layer to the other layer. A recording medium can be manufactured.

It is sectional drawing which shows the structure of an example of the sheet | seat for multilayer optical recording media of this invention. It is sectional drawing which shows the structure of the example from which the sheet | seat for multilayer optical recording media of this invention differs. It is sectional drawing which shows the structure of another different example of the sheet | seat for multilayer optical recording media of this invention. It is sectional drawing which shows the structure of another different example of the sheet | seat for multilayer optical recording media of this invention. It is sectional drawing which shows one example of a structure of the multilayer structure for optical recording media of this invention.

Explanation of symbols

1, 1-1, 1-2, 1-3, 1-n Dye material thin film 2, 2-1, 2-2, 2-3, 2-n Adhesive layer 3 First release film 4 Second release film DESCRIPTION OF SYMBOLS 5 Transparent resin layer 6 Curing transfer layer 6a Recording pit and / or groove 7 Substrate 10, 10a, 10b, 10c Multilayer optical recording medium sheet 20 Multilayer structure for optical recording medium

Claims (7)

  A sheet for producing a multilayer optical recording medium having a repeated structure in which a plurality of optical recording layers are laminated, wherein the sheet has a structure in which a dye material thin film and an adhesive layer are laminated, and the adhesive layer A multilayer optical recording medium sheet, wherein the glass transition temperature Tg of the constituting adhesive is -10 to 100 ° C.   The multilayer optical recording medium sheet according to claim 1, wherein the lamination temperature when producing the multilayer optical recording medium is 10 ° C. or higher and 120 ° C. or lower than the Tg of the adhesive.   The multilayer optical recording medium sheet according to claim 1, wherein the adhesive has an adhesive strength of 500 to 50,000 mN / 25 cm.   The multilayer optical recording medium sheet according to any one of claims 1 to 3, wherein the dye material constituting the dye material thin film contains a multiphoton absorbing material.   A multilayer for an optical recording medium, characterized in that an optical recording layer formed using the sheet according to any one of claims 1 to 4 and made of a dye material thin film and an adhesive layer are alternately laminated. Structure.   The multilayer structure for an optical recording medium according to claim 5, wherein position information is provided inside.   A multilayer optical recording medium comprising the multilayer structure according to claim 5.

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