WO2013175754A1 - Ultraviolet curable resin composition and blu-ray disc - Google Patents

Ultraviolet curable resin composition and blu-ray disc Download PDF

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Publication number
WO2013175754A1
WO2013175754A1 PCT/JP2013/003183 JP2013003183W WO2013175754A1 WO 2013175754 A1 WO2013175754 A1 WO 2013175754A1 JP 2013003183 W JP2013003183 W JP 2013003183W WO 2013175754 A1 WO2013175754 A1 WO 2013175754A1
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Prior art keywords
meth
acrylate
resin composition
curable resin
blu
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PCT/JP2013/003183
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French (fr)
Japanese (ja)
Inventor
潤 木戸場
雄一朗 松尾
小林　大祐
正弘 内藤
隼 本橋
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日本化薬株式会社
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Priority to CN201380026648.XA priority Critical patent/CN104395961A/en
Publication of WO2013175754A1 publication Critical patent/WO2013175754A1/en

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
    • C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
    • C08F290/06—Polymers provided for in subclass C08G
    • C08F290/062—Polyethers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24302—Metals or metalloids
    • G11B2007/24306—Metals or metalloids transition metal elements of groups 3-10
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24302—Metals or metalloids
    • G11B2007/24312—Metals or metalloids group 14 elements (e.g. Si, Ge, Sn)
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
    • G11B2007/24318—Non-metallic elements
    • G11B2007/2432—Oxygen
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/254—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers
    • G11B2007/25402—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of protective topcoat layers consisting essentially of organic resins

Definitions

  • the present invention provides a cured resin layer in an optical disc in which at least a light reflection layer and a light transmission layer are formed, and recording or reproduction is performed with a blue laser having an oscillation wavelength within a range of 370 nm to 430 nm through the light transmission layer,
  • the present invention relates to an ultraviolet curable resin composition used for a light transmissive layer and an optical disk using a cured product layer of the ultraviolet curable resin composition, preferably as a light transmissive layer.
  • DVD Digital Versatile Disc
  • CD Compact Disc
  • HDTV High Definition Television
  • This new optical disc has a structure in which an information recording site such as a pit or an information recording layer is formed on a transparent or opaque substrate made of plastic such as polycarbonate, and then a light transmission layer of about 100 ⁇ m is laminated on the information recording site. is doing.
  • the optical disk has a structure in which recording light and / or reproducing light is incident on the light transmission layer. From the viewpoint of productivity, the use of an ultraviolet curable resin composition for the light transmission layer of this optical disc has been studied exclusively.
  • the light transmission layer of the BD is thicker than the light transmission layer used in a DVD.
  • a light transmission layer is provided on the surface layer or in the vicinity of the surface layer.
  • an ultraviolet curable resin composition capable of reducing warpage of an optical disk for example, urethane (meth) acrylate obtained by reacting a lactone compound with a hydroxyl group-containing (meth) acrylate and a polyisocyanate compound is used.
  • the ultraviolet curable resin composition to contain is disclosed (refer patent document 1).
  • the ultraviolet curable resin composition is an ultraviolet curable resin composition useful as a protective coating agent having a low curing shrinkage and a low viscosity by using urethane (meth) acrylate having relatively excellent flexibility.
  • the composition has a low viscosity for a light transmission layer for BD, it is difficult to form a thick film.
  • the light transmission layer of the optical disk is formed by increasing the content of urethane (meth) acrylate in order to improve the viscosity, there is a problem that deterioration due to corrosion of the metal film occurs in a high temperature and high humidity environment. It was.
  • the resin composition containing urethane (meth) acrylate and epoxy (meth) acrylate is disclosed as a composition with small distortion and excellent toughness and heat resistance (see Patent Document 2).
  • the composition contains a certain amount or more of urethane (meth) acrylate in the ultraviolet curable resin composition to suppress distortion during curing and impart toughness, but urethane (meth) acrylate changes in temperature. Since it is easily affected by a change in warpage due to a change in humidity, there has been a problem that the reliability of the recording medium is reduced when a change in humidity or temperature occurs in an environment where the recording medium is stored.
  • an optical recording medium provided with a cured product of a conventional ultraviolet curable resin composition a certain amount or more of urethane (meth) acrylate is contained to suppress distortion, and thus the storage environment is restricted. That is, since a recording medium provided with a cured product of an ultraviolet curable resin composition with a small amount of warpage is easily affected by temperature changes, the amount of warpage changes in a high temperature environment (30 ° C. to 40 ° C.) such as summer. There has been a problem of increasing. Further, when the hard coat layer is not provided, there is a concern that the optical recording media adhere to each other with the ultraviolet curable resin composition under storage and management in a high temperature environment in summer.
  • a resin composition containing epoxy (meth) acrylate is disclosed as an ultraviolet curable resin composition having a high elastic modulus (see Patent Document 3).
  • the epoxy (meth) acrylate has a very large warp upon curing, and a recording medium with excellent reliability cannot be obtained without a component that imparts flexibility.
  • urethane (meth) acrylate is used as a component for imparting flexibility, the above-described problems cause a decrease in reliability and an adverse effect on storage in a high temperature environment (30 ° C. to 40 ° C.). Therefore, in the case of using the conventional ultraviolet curable resin composition, it is difficult to reduce the warp without reducing the reliability in the optical disk having the ultraviolet curable resin cured material layer having a film thickness. .
  • the problem to be solved by the present invention is that when cured, a glass transition temperature (Tg) is higher than a certain level and a cured product having a high elastic modulus is given, and when applied to an optical disc, there is little warping during curing.
  • Tg glass transition temperature
  • It is an ultraviolet curable resin composition, and further has a highly reliable cured layer with little change in warpage even when humidity change or temperature change occurs, that is, when it is stored in a high temperature and high humidity environment.
  • an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound and a (meth) acrylate compound having a carboxy group as an epoxy (meth) acrylate, and a monofunctional (meth) acrylate compound Is applied to an optical disc (preferably a Blu-ray disc) as, for example, a light transmission layer, etc., so that the amount of change in warpage due to humidity change or temperature change is small, and in a high temperature environment.
  • an optical disc preferably a Blu-ray disc
  • optical discs with little change in warpage due to humidity change or temperature change are unlikely to cause a decrease in light reflectivity due to warpage and little deterioration in signal characteristics. Since it is good, it is useful as a Blu-ray Disc.
  • the term “(meth) acrylate compound having a carboxy group” is used in the same meaning as a (meth) acryl compound containing both a carboxy group and a (meth) acryl group. Therefore, in the present specification, “(meth) acrylate compound having a carboxy group” includes (meth) acrylic acid.
  • (meth) acrylic acid is used to mean either or both of acrylic acid and methacrylic acid
  • (meth) acrylate is similarly any one of acrylate and methacrylate. Or it is used in the meaning of both.
  • At least a light reflection layer and a light transmission layer are laminated on a substrate, and a cured resin layer of an optical disk (preferably a blue laser is incident from the light transmission layer side to reproduce information) Is a Blu-ray disc having an ultraviolet curable resin composition used for the light transmission layer), a cured product thereof, and a cured product layer of the resin composition.
  • a cured resin layer of an optical disk preferably a blue laser is incident from the light transmission layer side to reproduce information
  • the present invention relates to the following (1) to (18).
  • An epoxy (meth) acrylate (A) obtained by reacting (i) a glycidyl ether type epoxy compound and a (meth) acrylate compound having a carboxy group in an ultraviolet curable resin composition for Blu-ray Disc, (Ii) The monofunctional (meth) acrylate compound (B) and (iii) the photopolymerization initiator (C), the content of the epoxy (meth) acrylate (A) with respect to 100 parts by weight of the total amount of the resin composition When the ratio is 30 parts by weight or more, the content is A parts by weight, and the content of the monofunctional (meth) acrylate compound (B) is B parts by weight, the A / B is 0.8 to 1.
  • Epoxy (meth) acrylate (A) obtained by reacting a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group, a monofunctional (meth) acrylate compound (B), and photopolymerization initiation
  • An ultraviolet curable resin composition for Blu-ray Disc containing an agent (C), wherein the content of the epoxy (meth) acrylate (A) is 30 parts by weight or more with respect to 100 parts by weight of the total amount of the resin composition UV curing for Blu-ray discs with an A / B of 0.8 to 1.45, where the content is A parts by weight and the content of the monofunctional (meth) acrylate compound (B) is B parts by weight.
  • the (meth) acrylate compound having a carboxy group is (a) an unsaturated carboxylic acid or a derivative thereof, or (b) a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride (The ultraviolet curable resin composition for Blu-ray Discs as described in (2) above, which is a compound obtained from b2).
  • the glycidyl ether type epoxy compound has the following formula (2) Formula (2) (In the formula, n represents an integer of 0 to 20.) And an epoxy equivalent of 180 g / eq. ⁇ 200 g / eq.
  • the urethane (meth) acrylate is further contained in a proportion of 20 parts by weight or less with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition.
  • the ultraviolet curable resin composition for Blu-ray Discs according to any one of the above.
  • the epoxy (meth) acrylate (A) is represented by the following formula (2) (Where n represents an integer of 1 to 10)
  • the epoxy resin (meth) acrylate (A) obtained by reacting a glycidyl ether type epoxy compound represented by the formula (meth) acrylic acid with the glycidyl ether type epoxy compound represented by the above (2) to (9): UV curable resin composition for Blu-ray Disc.
  • the content ratio B weight of the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound (B) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition The ultraviolet curable resin composition for Blu-ray Discs according to any one of the above (2) to (10), wherein the total amount is at least 80 parts by weight.
  • the ultraviolet curable resin composition for Blu-ray Disc is irradiated with ultraviolet rays, and the cured product formed after the ultraviolet irradiation has an elastic modulus at 50 ° C. of 450 to 1500 MPa, any one of (2) to (12) Item 4.
  • a Blu-ray disc having a light transmission layer obtained by applying the ultraviolet curable resin composition according to any one of (1) to (13) above to an optical disc substrate and irradiating with active energy rays.
  • the glass transition temperature Tg of the cured product according to the above (14) is at least 40 ° C., the amount of initial warpage of the Blu-ray disc having the cured product layer, and the relative humidity of 85% at 80 ° C.
  • the Blu-ray disc as described in (16) or (17) above, wherein both values of the amount of change in warpage after the durability test after exposure for 250 hours in the above environment are both less than ⁇ 0.6 degrees.
  • the ultraviolet curable resin composition for Blu-ray Disc of the present invention (hereinafter also referred to as the ultraviolet curable resin composition of the present invention or the resin composition of the present invention) has a high glass transition point (Tg) when cured. A cured product having a high elastic modulus and good recoverability can be obtained.
  • Tg glass transition point
  • the resin composition when applied to a Blu-ray disc, it can form a cured film that has less warpage during curing, has excellent curability, and has reduced warpage change due to changes in humidity and temperature. it can.
  • an optical disc (preferably a Blu-ray disc) provided with a cured product layer of the ultraviolet curable resin composition of the present invention is a highly reliable optical disc with a small amount of change in warpage during curing and after an endurance test, and in a high temperature environment. Easy to store at (30 °C ⁇ 40 °C).
  • the ultraviolet curable resin composition of the present invention is an epoxy (meth) obtained by reacting a monofunctional (meth) acrylate (B) and a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group. At least both of acrylate (A) are contained in a specific ratio. That is, 30 parts by weight or more of epoxy (meth) acrylate (A) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition of the present invention, and the content ratio is A part by weight.
  • the content of the (meth) acrylate (B) is B parts by weight, both of the above are contained within a range where A / B is 0.8 to 1.45.
  • the preferred range of A / B is 0.8 to 1.3, more preferably 0.8 to 1.1.
  • Monofunctional (meth) acrylates include isooctyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, cetyl (meth) acrylate, and isomyristyl (meth) C5 to C20 (preferably C7 to C18) alkyl (meth) acrylate such as acrylate and tridecyl (meth) acrylate; benzyl (meth) acrylate, phenylglycidyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, the above formula (Meth) acrylate compounds having a
  • Preferred monofunctional (meth) acrylates among the above include phenoxyethyl acrylate represented by the above formula (1), benzyl (meth) acrylate, phenylglycidyl (meth) acrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate, (Meth) acrylate compounds having a benzene ring such as dicyclopentadieneoxyethyl (meth) acrylate, dicyclopentenyl acrylate (for example, FANCYL FA-511A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenyloxyethyl acrylate (for example, Dicyclope such as FANCYL FA-512A manufactured by Hitachi Chemical Co., Ltd.) and dicyclopentenyloxyethyl methacrylate (for example, FANCYL FA-512M manufactured by Hitachi Chemical Co., Ltd.) Thenyl have groups or dicyclopentadiene group (meth
  • dicyclopentenyloxyethyl acrylate or a (meth) acrylate compound represented by the following formula (1) is preferable.
  • a monofunctional (meth) acrylate compound having one (meth) acryloyl group improves the mechanical properties (suppression of warpage, distortion, etc.) of an optical disk formed with the ultraviolet curable resin composition of the present invention as a light transmission layer. It has a function. Accordingly, as a preferred embodiment of the present invention, a case where the monofunctional (meth) acrylate compound includes one or both of a compound represented by the following formula (1) and dicyclopentenyloxyethyl (meth) acrylate is exemplified. I can do it.
  • the aspect containing the compound represented by following formula (1) can be mentioned.
  • the total content ratio of one or both of the compound represented by the following formula (1) and dicyclopentenyloxyethyl (meth) acrylate with respect to 100 parts by weight of the total amount of the resin composition of the present invention is B1 weight.
  • a / B1 is preferably 0.8 to 1.45, more preferably 0.8 to 1.3, and particularly preferably 0.8 to 1.1.
  • the efficacy of the compound represented by the following formula (1) and / or dicyclopentenyloxyethyl (meth) acrylate component is sufficiently exhibited.
  • the monofunctional (meth) acrylate (B) includes a compound represented by the following formula (1) and / or a monofunctional (meth) acrylate other than dicyclopentenyloxyethyl (meth) acrylate It does not have to be, but may be included as necessary.
  • a preferred content of the compound represented by the formula (1) and / or dicyclopentenyloxyethyl (meth) acrylate with respect to 100 parts by weight of the total amount of the monofunctional (meth) acrylate (B) is 50 to 100 parts by weight, The amount is preferably 80 to 100 parts by weight, more preferably 90 to 100 parts by weight, and still more preferably 95 to 100 parts by weight.
  • the balance is the other monofunctional (meth) acrylate.
  • the other monofunctional (meth) acrylate is included, the effect of the present invention may be achieved even if A / B is out of the range of 0.8 to 1.45. In this case, it falls within the scope of the present invention.
  • n represents an integer of 1 to 10.
  • the compound represented by these can be used.
  • n is preferably 1 to 3.
  • Specific examples of the compound represented by the formula (1) to be used include ethylene oxide-modified phenol (meth) acrylate.
  • the compound can be obtained from the market.
  • Specific examples of the product include Photomer 4035 (for example, manufactured by Cognis Co., Ltd.), EBECRYL110 (for example, manufactured by Daicel Cytec Co., Ltd.), and the like.
  • the content of the monofunctional (meth) acrylate compound (B) in the ultraviolet curable resin composition of the present invention is usually 10 to 60 parts by weight with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition.
  • a range that satisfies the condition of 8 to 1.45 is preferable, and 20.7 parts by weight or more is preferable.
  • the content of the monofunctional (meth) acrylate compound (B) is particularly preferably in the range of 20 to 40 parts by weight and in the range satisfying the above relationship with the epoxy (meth) acrylate (A). is there.
  • the amount is less than 10 parts by weight, there is a possibility that adhesion, flexibility, and restorability cannot be achieved, and when it exceeds 60 parts by weight, there is a possibility that sufficient hardness cannot be obtained.
  • epoxy (meth) acrylate (A) is used.
  • Epoxy (meth) acrylate (A) has the function of improving curability, improving the hardness and curing speed of the cured product, and improving the curability at the time of curing, and the adhesiveness at the time of softening to urethane (meth) acrylate There is a function to suppress compared.
  • Any epoxy (meth) acrylate (A) may be used as long as it is obtained by reacting a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group.
  • Preferred glycidyl ether type epoxy compounds for obtaining the epoxy (meth) acrylate (A) include diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, and hydrogenated bisphenol.
  • the epoxy (meth) acrylate (A) that can be suitably used in the present invention is a bisphenol A type epoxy acrylate obtained from a bisphenol A type epoxy compound.
  • the bisphenol A type epoxy acrylate include an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound of bisphenol A with a (meth) acrylate compound having a carboxy group. More specifically, the following formula (2) (In the formula, n represents an integer of 0 to 20.) An epoxy (meth) acrylate obtained by reacting a liquid glycidyl ether type epoxy compound represented by the formula (2) with a (meth) acrylate compound having a carboxy group can be suitably used.
  • the equivalent is 150 g / eq. ⁇ 550 g / eq. And more preferably 180 g / eq. ⁇ 200 g / eq. It is.
  • Epoxy equivalent is 150 g / eq. If it is lower, the warp when the ultraviolet curable resin composition is cured may be too large, and 550 g / eq. This is because it is likely to be affected by the temperature change due to summer and storage may become difficult.
  • (meth) acrylate compound having a carboxy group (a) an unsaturated carboxylic acid or a derivative thereof, and (b) a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride (b2)
  • a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride (b2) The compound obtained from is mentioned.
  • Examples of the unsaturated carboxylic acid (a) or derivative thereof include (meth) acrylic acid (acrylic acid or methacrylic acid), maleic acid, ⁇ -ethylacrylic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthal Acids, unsaturated carboxylic acids such as methyltetrahydrophthalic acid, and derivatives of these acid halides, amides, imides, anhydrides, esters, and the like can be used. Of these, (meth) acrylic acid is preferred.
  • Examples of the compound (b), that is, the compound obtained from the lactone adduct (b1) of the hydroxy (meth) acrylate compound and the polybasic acid anhydride (b2) include, for example, a lactone adduct of the hydroxy (meth) acrylate compound. And a compound obtained by reacting the polybasic acid anhydride in a molar ratio of 0.9 to 1.1, preferably equimolar. The above reaction is desirably carried out in the presence of a polymerization inhibitor at a reaction temperature of 50 to 150 ° C., preferably 60 to 120 ° C.
  • the lactone adduct (b1) of a hydroxy (meth) acrylate compound can be obtained by ring-opening addition of a lactone to a hydroxy (meth) acrylate compound.
  • the hydroxy (meth) acrylate compound include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylol cyclohexyl mono (meth) acrylate, hydroxycaprolactone (meth) acrylate, and the like. Among these, use of hydroxyethyl (meth) acrylate is preferable.
  • lactone ⁇ -propiolactone, ⁇ -butyrolactone, ⁇ -butyrolactone, ⁇ -valerolactone, ⁇ -valerolactone, ⁇ -methyl- ⁇ -valerolactone, ⁇ -caprolactone, ⁇ -caprolactone, etc. may be used. it can. A compound in which 2 mol of ⁇ -caprolactone is added to 1 mol of hydroxy (meth) acrylate compound is preferred.
  • polybasic anhydride (b2) examples include phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride and derivatives thereof, 3,4,5,6-tetrahydrophthalic anhydride and derivatives thereof, 1 2,3,4-tetrahydrophthalic anhydride and derivatives thereof, 2,3,4,5-tetrahydrophthalic anhydride and derivatives thereof, hexahydrophthalic anhydride and derivatives thereof, succinic anhydride and derivatives thereof Monoalkyl succinic anhydride and derivatives thereof, dialkyl succinic anhydride and derivatives thereof, maleic anhydride and derivatives thereof, monoalkyl maleic anhydride and derivatives thereof, and dialkyl maleic anhydride and derivatives thereof. Of these, phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride are preferably used.
  • the epoxy (meth) acrylate (A) is obtained by reacting these glycidyl ether type epoxy compounds with a (meth) acrylate compound having a carboxy group under the following conditions.
  • the carboxy group of the (meth) acrylate compound having a carboxy group is 0.9 to 1.5 equivalents, more preferably 0.95 to 1.1 equivalents with respect to 1 equivalent of the epoxy group of the glycidyl ether type epoxy compound.
  • the reaction temperature is preferably 80 to 120 ° C., and the reaction time is about 10 to 35 hours.
  • a catalyst such as triphenylphosphine, TAP (trialkylphosphine), triethanolamine, or tetraethylammonium chloride.
  • TAP triphenylphosphine
  • triethanolamine triethanolamine
  • tetraethylammonium chloride tetraethylammonium chloride.
  • paramethoxyphenol, methylhydroquinone or the like can be used as a polymerization inhibitor.
  • the content of the epoxy (meth) acrylate (A) is usually 30 parts by weight or more with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition of the present invention, preferably The amount is 40 parts by weight or more, and more preferably 50 parts by weight or more.
  • an upper limit is not specifically limited, Usually, it is 80 weight part or less, Preferably it is 70 weight part or less, More preferably, it is 60 weight part or less. This is because if the amount is less than 30 parts by weight, the amount of change in warpage due to humidity change or temperature change is increased, surface curability is inferior, and it may work as an adhesive during high temperature storage.
  • an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound and (meth) acrylic acid as the epoxy (meth) acrylate (A) ( A1) is contained.
  • the total amount of the ultraviolet curable resin composition is 100 parts by weight.
  • the content ratio of the epoxy (meth) acrylate (A1) (parts by weight of the component (A1) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition) is A1 parts by weight
  • the monofunctional (meth) acrylate compound (B ) Content (parts by weight of component (B) relative to 100 parts by weight of the total amount of the ultraviolet curable resin composition) is B parts by weight
  • A1 / B is preferably in the range of 0.8 to 1.45. If the said ratio is less than 0.8, stability at the time of high temperature storage will be inferior, and if it exceeds 1.45, the curvature at the time of hardening will become large.
  • A1 / B1 Is more preferably the same as the range of A1 / B, that is, when A1 / B1 is in the range of 0.8 to 1.45.
  • the monofunctional (meth) acrylate (B) contains the compound represented by the formula (1) or dicyclopentenyl (meth) acrylate, and A1 / B1 is in the above range.
  • other monofunctional (meth) acrylate compounds may not be included, but other monofunctional (meth) acrylate compounds may be included as necessary.
  • the other monofunctional (meth) acrylate is included, the effect of the present invention may be achieved even if A / B is out of the range of 0.8 to 1.45. In this case, it falls within the scope of the present invention.
  • the content ratio (A / B) of both the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound is 0.8 to 1.45.
  • the content ratio of the epoxy (meth) acrylate (A) to the total amount of 100 parts by weight of the ultraviolet curable resin composition in the ultraviolet curable resin composition is as high as 30 parts by weight or more, the warp at the time of curing. Can be effectively reduced, and restoring properties and curability can also be imparted.
  • the monofunctional (meth) acrylate (B) is bonded to the polyfunctional epoxy (meth) acrylate (A) at the above ratio, so that further crosslinking is suppressed by the monofunctional (meth) acrylate. Can be prevented from being carried out in a highly three-dimensional manner, and an excellent balance between warpage during curing and storage in a high temperature environment can be realized.
  • a monofunctional (meth) acrylate when the compound of the above formula (1) is blended with the epoxy (meth) acrylate at the above ratio, the shrinkage is particularly low while maintaining the characteristics of the epoxy (meth) acrylate. And flexibility can be imparted.
  • the amount of change in warpage due to changes in humidity and temperature can be suppressed to a level that does not cause spec-out by less than plus or minus 0.6. Things can be provided.
  • any of the above-mentioned changes can be suppressed to plus or minus 0.5 or less, more preferably plus or minus 0.4 or less, and the reliability of recording characteristics is further improved. Can be improved. From the viewpoint of imparting better curving reduction performance during curing, a function of suppressing warpage change due to temperature change, or warpage change after endurance test, A / B is less than 0.8 to less than 1.41 Is preferred.
  • the A / B is more preferably 0.8 to 1.3, and still more preferably 0.8 to 1.1.
  • the amount of change in warpage during curing, the amount of change in warpage due to temperature change, or the amount of change in warpage after the durability test is plus or minus 0.6 or more, based on the warpage of the substrate before applying the resin. If so, the recording characteristics are poor and the concern about reliability increases.
  • the contents of both the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound (B) are as described above.
  • the amount is usually 80 to 99% by weight, preferably 90 to 99 parts by weight, more preferably 92 to 97 parts by weight, per 100 parts by weight of the total amount of the resin composition.
  • a photopolymerization initiator (C) is used.
  • the photopolymerization initiator (C) that can be used in the present invention include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, benzyl, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- (4-methylthiophenyl) )
  • Molecular cleavage type such as 2-morpholinopropan-1-one, hydrogen abstraction type photopolymerization initiator such as benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenyl sulf
  • the content of the photopolymerization initiator (C) in the ultraviolet curable resin composition is usually 1 to 10 parts by weight, preferably 3 to 8 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. It is.
  • urethane (meth) acrylate can be contained if necessary.
  • a suitable amount of urethane (meth) acrylate there is a function of improving the mechanical properties (warping, distortion, etc.) of the optical disk.
  • Urethane (meth) acrylate that can be suitably used in combination can be obtained by reacting polyhydric alcohol, polyisocyanate and hydroxy (meth) acrylate compound.
  • polyhydric alcohol examples include the following polyhydric alcohols.
  • polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol
  • Neopentyl glycol 3-methyl-1,5-pentanediol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, tricyclodecane dimethylol, bis- Aliphatic alcohols such as [hydroxymethyl] -cyclohexane
  • a polyester polyol obtained by reacting one of the aliphatic polyhydric alcohols described in (i) above with a polybasic acid.
  • the polybasic acid examples include succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, and tetra
  • Caprolactone alcohol obtained by reaction of polyhydric alcohol and ⁇ -caprolactone.
  • Polycarbonate polyol For example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate.
  • Polyether polyol For example, poly C2-C3 alkylene glycol such as polyethylene glycol or polypropylene glycol, ethylene oxide modified bisphenol A and the like. These number average molecular weights are preferably about 200 to 8000, more preferably about 200 to 3000.
  • polyisocyanate examples include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4′-diisocyanate, and dicyclopentanyl isocyanate.
  • isophorone diisocyanate or tolylene diisocyanate is preferred.
  • the hydroxy (meth) acrylate compounds that can be used include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylol cyclohexyl mono (meth) acrylate, and hydroxycaprolactone (meth) acrylate. Etc. Among these, use of hydroxyethyl (meth) acrylate is preferable.
  • the reaction is performed, for example, as follows. That is, the polyhydric alcohol is mixed with an organic polyisocyanate per equivalent of the hydroxyl group so that the isocyanate group is preferably 1.1 to 2.0 equivalent, and reacted at a reaction temperature of preferably 70 to 90 ° C. Synthesize oligomers. Next, the hydroxy (meth) acrylate compound is mixed so that the hydroxyl group is preferably 1 to 1.5 equivalents per equivalent of the isocyanate group of the urethane oligomer, and reacted at 70 to 90 ° C. to react with the target urethane (meth). ) Acrylate can be obtained.
  • the molecular weight of urethane (meth) acrylate is preferably about 400 to 10,000.
  • the weight average molecular weight of the urethane (meth) acrylate is preferably about 7,000 to 25,000, and more preferably 10,000 to 20,000. When the weight average molecular weight is less than 7000, shrinkage increases, and when the weight average molecular weight is greater than 25000, curability is poor.
  • the content of urethane (meth) acrylate in the ultraviolet curable resin composition of the present invention improves adhesion, flexibility, and resilience while imparting a function to suppress the change in warpage due to changes in humidity and temperature, and hardness.
  • it is 0 to 20 parts by weight, preferably 0 to 10 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. If the amount exceeds 20 parts by weight, sufficient hardness cannot be obtained, and problems such as inferior function of suppressing change in warpage due to humidity change and temperature change occur, and the intended effect of the present invention cannot be achieved. It is not preferable.
  • the content of urethane (meth) acrylate is preferably 20 parts by weight or less.
  • the resin composition of the present invention may contain a polyfunctional (meth) acrylate compound (hereinafter also referred to as (meth) acrylate monomer other than (B)) as necessary.
  • a polyfunctional (meth) acrylate compound hereinafter also referred to as (meth) acrylate monomer other than (B)
  • the term “polyfunctional (meth) acrylate compound” or “(meth) acrylate monomer other than (B)” refers to a polyfunctional (meta) excluding the urethane (meth) acrylate and epoxy (meth) acrylate. )
  • any monomer having a plurality of (meth) acryloyl groups may be used, but usually 2 to 6 polyfunctional (meth) acrylate compounds (hereinafter referred to as 2 (meth) acryloyl groups).
  • 2 (meth) acryloyl groups usually 2 to 6 polyfunctional (meth) acrylate compounds (hereinafter referred to as 2 (meth) acryloyl groups).
  • di (meth) acrylate monomers are preferred.
  • Examples of the (meth) acrylate monomer having two (meth) acryloyl groups include cyclohexane-1,4-dimethanol di (meth) acrylate, cyclohexane-1,3-dimethanol di (meth) acrylate, and tricyclodecane dimethylol di (meth).
  • Di (meth) acrylates having C5-C10 aliphatic rings such as acrylates (for example, KAYARAD R-684, tricyclodecane dimethylol diacrylate, etc., manufactured by Nippon Kayaku Co., Ltd.), dicyclopentanyl di (meth) acrylate, etc.
  • di (meth) acrylate compounds having a heterocycle such as dioxane glycol di (meth) acrylate (for example, KAYARAD R-604, dioxane glycol diacrylate, etc., manufactured by Nippon Kayaku Co., Ltd.), ethylene oxide modified 1,6- It has a branched chain such as C2-C10 alkyl di (meth) acrylate such as xanthdiol di (meth) acrylate and its alkylene oxide modified product, neopentyl glycol di (meth) acrylate, alkylene oxide modified neopentyl glycol di (meth) acrylate, etc.
  • dioxane glycol di (meth) acrylate for example, KAYARAD R-604, dioxane glycol diacrylate, etc., manufactured by Nippon Kayaku Co., Ltd.
  • ethylene oxide modified 1,6- It has a branched chain such as C2-C10 alkyl di (meth
  • C2-C10 alkylene di (meth) acrylate and its modified alkylene oxide polypylene glycol diglycol dihydroxypivalate neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, etc.
  • C2 to C10 alkylene di (meth) acrylate or a modified alkylene oxide thereof from the viewpoint of suppressing the amount of warpage due to a temperature change, from the viewpoint of durability, and from the viewpoint of improving hardness.
  • the (meth) acrylate monomer having three (meth) acryloyl groups includes trimethylol C2 such as trimethylolpropane tri (meth) acrylate and trimethyloloctanetri (meth) acrylate.
  • Trimethylol C2 to C10 such as C10 alkane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, trimethylolpropane polyethoxypolypropoxytri (meth) acrylate Alkane polyalkoxy tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, pentaerythritol tri (meth) acrylate, ethylene Side-modified trimethylolpropane tri (meth) acrylate, alkylene oxide modified trimethylolpropane tri (meth) acrylate such as propylene oxide-modified trimethylolpropane tri (meth) acrylate.
  • (Meth) acrylate monomers other than (B) (meth) acrylate monomers having four (meth) acryloyl groups include pentaerythritol polyethoxytetra (meth) acrylate, pentaerythritol polypropoxytetra (meth) acrylate, and pentaerythritol. Examples include tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and dipentaerythritol tetra (meth) acrylate.
  • Examples of the (meth) acrylate monomer having five (meth) acryloyl groups include dipentaerythritol penta (meth) acrylate.
  • examples of the (meth) acrylate monomer having 6 (meth) acryloyl groups include dipentaerythritol hexa (meth) acrylate.
  • the (meth) acrylate monomer that can be used in the present invention may be a polyfunctional monomer having 7 or more (meth) acryloyl groups.
  • these (meth) acrylate monomer components can be used alone or in admixture of two or more at any ratio.
  • the content of these (meth) acrylate monomer components in the ultraviolet curable resin composition is usually about 0 to 10 parts by weight, and in some cases, 10 to 80 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition.
  • the amount is preferably 20 to 70 parts by weight.
  • Additives that can be used in the ultraviolet curable resin composition of the present invention include sensitizers, silane coupling agents, surfactants, leveling agents, thermal polymerization inhibitors, antioxidants such as hindered phenols and phosphites, Light stabilizers such as hindered amines can also be used. These may not be included in the resin composition of the present invention, but can be used as necessary.
  • the sensitizer examples include trimethylamine, methyldimethanolamine, triethanolamine, p-dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine and 4 4,4′-bis (diethylamino) benzophenone and the like can be used, and the photopolymerizable compound can be used in combination with an amine that does not cause an addition reaction.
  • any compound having a hindered piperidine skeleton can be used without particular limitation as long as it is a known one.
  • 2,2,6,6- Tetramethyl-4-piperidinone 2,2,6,6-tetramethyl-4-piperidinol, 1,2,2,6,6-pentamethyl-4-piperidinol, 4-hydroxy-2,2, 6,6-tetramethyl-1-piperidine ethanol, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate
  • 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate 1,2,6,6-tetramethyl-4-piperidyl methacrylate
  • 1,2,2,6,6-pentamethyl-4-piperidyl alcohol 2,2,6,6-tetramethyl-4-piperidyl alcohol, 1,2,2 , 6,6-pentamethyl-4-piperidyl (meth) acrylate (manufactured by Adeka Co., Ltd., LA-82) can be preferably used.
  • hinder refers to a hydrocarbon group having a branched chain bonded as a substituent to a compound having a piperidine skeleton.
  • the substituent is preferably t-butyl. It has a group.
  • the compound itself having a hindered piperidine skeleton is cross-linked, so that it is hardly precipitated as an impurity and does not impair the curability of the ultraviolet curable resin composition.
  • a compound having a hindered piperidine skeleton having an acryloyl group can be particularly preferably used.
  • the content of the compound having a hindered piperidine skeleton in the ultraviolet curable resin composition is usually 0.01 to 10 parts by weight, preferably 0.03 parts per 100 parts by weight of the total amount of the ultraviolet curable resin composition. -8 parts by weight, particularly preferably 0.03-5 parts by weight.
  • silane coupling agent Any known silane coupling agent can be used without any particular limitation as the silane coupling agent.
  • an antioxidant capable of imparting excellent durability can be added.
  • the content of the antioxidant in the ultraviolet curable resin composition is usually 0.01 to 10 parts by weight, preferably 0.03 to 8 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. Particularly preferred is 0.03 to 5 parts by weight.
  • the preferable aspect of the resin composition of this invention is shown below.
  • the epoxy (meth) acrylate (A) is an epoxy (meth) acrylate obtained by a reaction between a glycidyl ether type epoxy compound represented by the formula (2) and (meth) acrylic acid, Including a monofunctional (meth) acrylate compound (B),
  • the content ratio of the epoxy (meth) acrylate (A) is 30 to 60 parts by weight with respect to 100 parts by weight of the total amount of the resin composition of the present invention, the content ratio is A part by weight, and the monofunctional (meth) acrylate
  • a / B is 0.8 to 1.45
  • An ultraviolet curable resin composition for Blu-ray Disc wherein the content of the photopolymerization initiator (C) is 1 to 10 parts by weight with respect to 100 parts by weight of the total amount of the resin composition of the present invention.
  • dicyclopentenyloxyethyl (meth) acrylate is 100 parts by weight or less with respect to 100 parts by weight of the total amount of monofunctional (meth) acrylate compound (B).
  • the monofunctional (meth) acrylate compound (B) is a compound represented by the formula (1) alone, or both a compound represented by the formula (1) and dicyclopentenyloxyethyl (meth) acrylate.
  • the ultraviolet curable resin composition for an optical disk of the present invention can be obtained by mixing and dissolving the above-mentioned components at room temperature to 80 ° C. If necessary, impurities may be removed by an operation such as filtration.
  • the resin composition of the present invention has a coating property, and the viscosity of the ultraviolet curable resin composition of the present invention is preferably 300 to 2000 (mPa ⁇ s) at 25 ° C., and preferably 500 to 1200 (mPa ⁇ s). More preferably, s). By setting the viscosity within the range, thick film formation can be facilitated, and the tact time can be shortened.
  • the ultraviolet curable resin composition of the present invention it is preferable not to use a solvent, and even if it is used, it is preferably less than 10 parts by weight with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition. Particularly preferred is less than 5 parts by weight.
  • the cured product formed after ultraviolet irradiation has an elastic modulus at 25 ° C. of 1000 to 3000 MPa, more preferably 1500 to 2500 MPa, and more preferably 1800 to 2200 MPa. Is particularly preferred. This is because if it is less than 1000 MPa, sufficient hardness cannot be obtained, and if it exceeds 3000 MPa, warpage during curing may be too large. Further, the elastic modulus at 50 ° C. is usually 35 to 1500 MPa, preferably 45 to 1500 MPa. Furthermore, since the signal characteristic error caused by the temperature change can be effectively prevented when the warp due to the temperature change is small, the amount of change in the warp from 5 ° C. to 55 ° C.
  • the angle is preferably less than 0.6 degrees, and particularly preferably less than 0.6 degrees.
  • the amount of change in warpage (initial warpage) upon curing is small. It is preferable that the amount of change is a difference from the warpage of the substrate before coating, and less than 0.6 degrees.
  • the amount of change is 0.6 degrees or more, reading errors tend to increase rapidly.
  • it is 0.57 degree or less, More preferably, it is 0.5 degree or less, More preferably, it is 0.4 degree or less.
  • the amount of change in warpage after an endurance test in an optical disc, preferably a Blu-ray disc, having a cured product layer of the resin composition of the present invention as a light transmission layer is preferably less than 0.6 degrees. More preferably, it is 0.5 degrees or less, and still more preferably 0.4 degrees or less.
  • the glass transition temperature (Tg) in the hardened layer formed after ultraviolet irradiation is preferably 40 ° C. or higher. When the temperature is lower than 40 ° C., the elastic modulus rapidly decreases and the flexibility increases extremely in a high temperature environment (30 to 40 ° C.), so that it functions as an adhesive, that is, adhesion may occur. Because there is.
  • the optical disc of the present invention is an optical disc in which at least a light reflection layer and a light transmission layer are formed on a substrate, and recording or reproduction is performed with a laser beam through the light transmission layer. It consists of hardened
  • the optical disk of the present invention is excellent in that a cured product having a small amount of change in warpage due to humidity change and temperature change can be obtained by using the ultraviolet curable resin composition for optical disk of the present invention as a light transmission layer. In addition, information can be recorded / reproduced.
  • the light transmission layer in the optical disk of the present invention preferably transmits a blue laser having a laser light oscillation wavelength of 370 to 430 nm efficiently, and has a light transmittance of 405 nm at a thickness of 100 ⁇ m of 85% or more. Is preferable, and 90% or more is particularly preferable.
  • the total thickness of the light transmission layer is in the range of 50 to 150 ⁇ m, and 75 to 150 ⁇ m is particularly preferable. In the case of a single layer, the thickness of the light transmission layer is set to about 100 ⁇ m. However, since the thickness greatly affects the light transmittance and signal reading and recording, sufficient management is required.
  • the light transmission layer may be formed of a single cured layer having the thickness or a plurality of layers may be laminated. In the case of a plurality of layers, it is preferable that the sum of the thicknesses of the respective light transmission layers is in the above-mentioned thickness range.
  • the light reflecting layer may be any layer that can reflect a laser beam and form an optical disk that can be recorded and reproduced.
  • a metal such as gold, silver, copper, or aluminum or an alloy thereof, or an inorganic compound such as silicon. Can be used.
  • silver or an alloy containing silver as a main component is preferably used because of the high reflectance of light in the vicinity of 400 nm.
  • the thickness of the light reflecting layer is preferably about 10 to 60 nm.
  • the light reflecting layer is formed by vapor-depositing the metal or an alloy thereof on a substrate.
  • a disk-shaped circular resin substrate can be used, and polycarbonate can be preferably used as the resin.
  • the optical disc is read-only, pits for recording information are formed on the surface of the substrate that is laminated with the light reflecting layer.
  • a recording layer is provided between the light reflecting layer and the light transmitting layer.
  • the recording layer only needs to be capable of recording / reproducing information, and may be any of a phase change recording layer, a magneto-optical recording layer, and an organic dye recording layer.
  • a writable optical disc has a recording layer on the recording information surface of the substrate.
  • the recording layer a conventionally known material can be appropriately used as a recording layer for an optical recording medium. Examples thereof include a dye, an amorphous semiconductor, a partial nitride film, and a partial oxide film (inorganic film).
  • the optical recording medium may include a plurality of the recording layers.
  • each layer may be formed of the same material, or may be formed by arbitrarily combining different materials. By doing so, optical properties such as transmittance can be changed for each layer.
  • Specific examples of the recording layer include an inorganic type recording layer and an organic dye type recording layer.
  • the amorphous semiconductor material which is an inorganic type recording layer used for the recording layer include SbTe, GeTe, GeSbTe, InSbTe, AgSbTe, AgInSbTe, GeSb, GeSbSn, InGeSbTe, InGeSbSnTe And the like.
  • SbTe SbTe
  • GeSbTe GeSbTe
  • InSbTe AgInSbTe
  • GeSb GeSbSn
  • InGeSbTe InGeSbSnTe
  • InGeSbSnTe InGeSbSnTe
  • these amorphous semiconductor materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
  • partial nitride film and partial oxide film that are inorganic type recording layers used for the recording layer include partial nitride films such as BiGeN and SnNbN, and partial oxide films such as TeOx and BiFOx.
  • an organic dye type recording layer can be used as the recording layer.
  • the material of the organic dye-type recording layer needs to be sensitive to the wavelength of the laser beam used for recording and reproduction. Furthermore, the refractive index of the material of the organic dye-type recording layer needs to be changed by a physical change or chemical reaction caused by laser light irradiation. Therefore, examples of the material for the organic dye type recording layer include cyanine dyes, oxonol dyes, azo dyes, phthalocyanine dyes, and porphyrin dyes.
  • An organic dye type recording layer is formed by spin coating or the like using a solution obtained by mixing these organic materials with a solvent such as cellosolve acetate or tetrafluoropropanol.
  • the film thickness of the organic dye type recording layer is preferably 15 nm or more and 25 nm or less.
  • an interface layer may be provided on the recording layer.
  • the interface layer is required to have a function of buffering heat generated in the recording layer and a function of adjusting the reflectivity of the disc, and the dye contained in the organic dye type recording layer at the time of film formation of the light transmitting layer is applied to the light transmitting layer. It has a function of preventing mixing phenomena such as diffusion and penetration of a cured resin for forming a light transmission layer into an organic dye layer such as a solvent.
  • a mixed composition of silicon dioxide and zinc sulfide is usually used as the material constituting the interface layer.
  • silicon oxide particularly silicon dioxide, zinc oxide, cerium oxide, yttrium oxide, indium oxide, indium tin oxide, gallium oxide, etc.
  • This interface layer is formed by a method such as sputtering.
  • the ultraviolet curable resin composition of the present invention can be suitably used because of its excellent adhesion to an interface layer, specifically, a mixed composition of silicon dioxide and zinc sulfide and indium oxide and indium tin oxide.
  • two or more recording layers may be formed.
  • a first light reflection layer and a first light transmission layer are laminated on a substrate having pits, and the first light transmission layer or other layers are laminated,
  • a second light reflection layer and a second light transmission layer may be formed on the layer.
  • pits are formed on the first light transmission layer and other layers laminated thereon.
  • a recording layer, a light reflecting layer, and a light transmitting layer are laminated on a substrate, and the second light is further formed on the light transmitting layer.
  • the reflective layer, the second recording layer, and the second light transmission layer may be formed to have two recording layers, or the layers may be similarly stacked to have three or more recording layers. In the case of laminating a plurality of layers, it may be appropriately adjusted so that the sum of the layer thicknesses of the respective layers becomes the above-mentioned thickness.
  • the ultraviolet curable resin composition of the present invention is used for a light transmissive layer, corrosion or deterioration of an interface layer or a recording layer in contact with the light transmissive layer can be suppressed, and it can be suitably used for an optical disk having a recording layer. can do.
  • the light transmission layer may be the outermost layer, but a surface coat layer may be further provided on the surface layer.
  • the optical disc of the present invention includes a read-only disc and a recordable / reproducible disc.
  • a read-only disk When a single circular resin substrate is injection-molded, a read-only disk is provided with pits which are information recording layers, and then a light reflecting layer is formed on the information recording layer.
  • the UV curable resin composition for the light transmitting layer is applied by, for example, 2P method, roll coating method, screen printing, spin coating method, etc., ultraviolet to near ultraviolet (as an active energy ray from one side or both sides) It can be produced by forming a light transmission layer by curing by irradiation with a wavelength of 200 to 400 nm.
  • a recordable / reproducible disc is formed by forming a light reflecting layer on a single circular resin substrate, providing a recording layer, and further spinning an ultraviolet curable resin composition for a light transmitting layer on the light reflecting layer. After applying by a coating method or the like, it can be produced by curing by ultraviolet irradiation to form a light transmission layer.
  • the lamp is not particularly limited as long as it is capable of irradiating ultraviolet rays to near ultraviolet rays (wavelength of 200 to 400 nm).
  • a xenon lamp, an electrodeless lamp, a metal halide lamp, a low pressure, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, or the like can be used.
  • the accumulated light amount When irradiating with ultraviolet rays, it is preferable to control the accumulated light amount to be 0.05 to 1 J / cm 2 . More preferably accumulated light amount is 0.05 ⁇ 0.8J / cm 2, particularly preferably 0.05 ⁇ 0.6J / cm 2.
  • the UV curable resin composition for light transmissive layer used in the optical disc of the present invention is excellent in curability, so that it is sufficiently cured even with a small amount of integrated light, and does not cause tack on the end face or surface of the optical disc. Furthermore, there is no warping or distortion of the optical disk.
  • a light reflection layer and a light transmission layer are laminated on a substrate, and a blue laser is incident from the light transmission layer side to transmit information.
  • a hard coat layer is further provided on the light transmission layer.
  • the light transmission layer is a layer made of a cured product of the ultraviolet curable resin composition of the present invention, and the thickness thereof is in the range of 100 ⁇ 10 ⁇ m.
  • the hard coat layer is preferably a layer having high hardness and excellent wear resistance.
  • the thickness of the hard coat layer is preferably 1 to 10 ⁇ m, and more preferably 3 to 5 ⁇ m.
  • the thickness of the substrate is about 1.1 mm, and the light reflecting layer is a thin film such as silver.
  • the single-layer type optical disc having a recording layer, for example, a light reflection layer, a first interface layer, a recording layer (either an inorganic type recording layer or an organic dye type recording layer is acceptable) on a substrate, A structure in which a second interface layer and a light transmission layer are laminated in this order, and a blue laser is incident from the light transmission layer side to record or reproduce information, and a structure in which a hard coat layer is further provided on the light transmission layer is there.
  • a first light reflection layer and a first light transmission layer are laminated on a substrate, and further, a second light reflection layer and a second light transmission layer are further formed thereon.
  • a two-layer type optical disc that records or reproduces information by injecting a blue laser from the second light transmission layer side.
  • the first light transmission layer and the second light transmission layer are layers made of a cured product of the ultraviolet curable resin composition, and at least one of the layers is a layer made of the ultraviolet curable resin composition of the present invention.
  • the thickness of the layer the sum of the thickness of the first light transmission layer and the thickness of the second light transmission layer is in a range of 100 ⁇ 10 ⁇ m.
  • the thickness of the substrate is about 1.1 mm, and the light reflecting layer is a thin film such as silver.
  • the light reflecting layer is a thin film such as silver.
  • a multilayer optical disc having a recording layer for example, a first light reflecting layer, a first interface layer, a first recording layer (inorganic type recording layer, organic dye type recording layer) may be formed on a substrate.
  • a second interface layer, and a first light transmission layer are laminated in this order, and further, a second light reflection layer, a third interface layer, a second recording layer (any of inorganic and organic dyes are possible),
  • a second light reflection layer, a third interface layer, a second recording layer any of inorganic and organic dyes are possible
  • the light transmission layer is made of a cured film of an ultraviolet curable resin composition having excellent adhesiveness.
  • a multilayer formed by laminating a layer made of a cured film of an ultraviolet curable resin composition capable of suitably forming a recording track may be formed.
  • a hard coat layer may be provided on the outermost layer.
  • a polycarbonate resin having a guide groove for tracking laser light called a recording track (groove) is manufactured by injection molding a polycarbonate resin.
  • a light reflection layer is formed on the surface of the substrate on the recording track side by sputtering or vapor-depositing a silver alloy or the like.
  • the ultraviolet curable resin composition of the present invention is applied on this, and the ultraviolet curable resin composition is cured by irradiating ultraviolet rays from one or both sides of the disk to form a light transmission layer or spin on this.
  • a hard coat layer is formed by coating or the like.
  • Examples 1 to 9 and Comparative Examples 1 to 4 were prepared as ultraviolet curable resin compositions having the compositions shown in Table 1 below.
  • a Blu-ray disc having an inorganic recording layer was prepared and evaluated for characteristics.
  • a reflective layer was formed by sputtering a silver alloy to a thickness of 100 nm on a polycarbonate substrate having a diameter of 12 cm and a thickness of 1.1 mm having guide grooves with a track pitch of 0.32 ⁇ m. Thereafter, TiSiO was sputtered to form an inorganic recording layer. Further, ZnS—SiO 2 (molar ratio 80:20) was sputtered to a thickness of about 15 nm to form an interface layer, and a Blu-ray Disc substrate was produced. 2.
  • the Blu-ray Disc substrate Place the Blu-ray Disc substrate on the spin table so that the reflective layer is on top, apply a circular cap treatment to cover the inner diameter of 11.5 mm, and then add 3.0 g of the present invention or the comparative UV curable resin composition On top of the cap. 3.
  • Spin coating was performed for 4 seconds to 7 seconds at a speed range of 900 rpm, and the coating film thickness was 95 ⁇ m.
  • the xenon flash lamp was irradiated with two shots, and cured so that the fluidity of the surface disappeared. 4).
  • the ultraviolet curable resin composition of the present invention was completely cured by irradiation from the upper side at 400 mJ / cm 2 for 3 seconds. 5.
  • the cured UV curable resin composition of the present invention is placed on a spin table so that a circular cap treatment is performed so as to cover the inner diameter of 11.5 mm, and then the UV curable resin composition for the hard coat layer is applied.
  • HOD3950B manufactured by Nippon Kayaku Co., Ltd.
  • the coating was performed by spin coating at a speed range of 6.6000 rpm for 4 to 7 seconds.
  • a xenon flash lamp was irradiated for 2 shots just before the end of spin coating and cured to such an extent that the surface fluidity disappeared, and the Blu-ray Disc of the present invention was produced.
  • EP-1 The epoxy equivalent represented by the above formula (2) is 187 g / eq.
  • Epoxy acrylate EP-2 obtained by reacting 1 mol of acrylic acid with 1 mol of the epoxy group of the glycidyl ether type epoxy compound: The epoxy equivalent represented by the above formula (2) is 193 g / eq.
  • Epoxy acrylate UA-1 obtained by reacting 1 mol of acrylic acid with 1 mol of epoxy group of the glycidyl ether type epoxy compound: Polypropylene glycol (number average molecular weight 850), isophorone diisocyanate and 2-hydroxylethyl
  • molar ratio of urethane acrylate UA-2 polytetramethylene glycol (number average molecular weight 650), isophorone diisocyanate and 2-hydroxylethyl acrylate obtained by reacting at a molar ratio of 1: 1.9: 1.9.
  • Photomer 4226 dipropylene glycol diacrylate, FA-321A manufactured by Cognis Co., Ltd .: ethylene oxide 10 mol modified bisphenol Type A diacrylate, Nippon Kasei Kogyo Co., Ltd. M-200: 1,6-hexanediol diacrylate, Bigen Co., Ltd. THE-330: Trimethylolpropane polyethoxytriacrylate, Nippon Kayaku Co., Ltd.
  • Photomer 4035 Phenoxy Ethyl acrylate, Cognis Co., Ltd.
  • FA-512AS Dicyclopentenyloxyethyl acrylate, Nippon Kasei Kogyo Co., Ltd.
  • M-142 Ethylene oxide 2 mol modified phenoxyethyl acrylate, Eternal Co., Ltd.
  • LA-82 1, 2, 2 , 6,6-Pentamethyl-4-piperidyl methacrylate, Asahi Denka Kogyo Co., Ltd. (currently ADEKA Corporation)
  • Speed Cure TPO 2,4,6-Trimethylbenzoyldiphenylphosphine oxide, DKSH Di Baker Ltd.
  • Irgacure 184 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF Corporation
  • the glass transition temperature (Tg) and the elastic modulus at 50 ° C. are determined by irradiating with ultraviolet rays for 3 seconds (100 mJ / cm 2 ) in the ultraviolet curable resin compositions obtained by the compositions of Examples and Comparative Examples.
  • a rectangular parallelepiped piece having a length of 4 mm, a width of 1 mm, and a height of 2 mm was prepared by using a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc.) DMS6100 in a double-end bending test method.
  • the temperature dependence data up to were measured with a frequency set at 10 Hz and a heating rate of 4 ° C./min.
  • the hardness test was performed using a Fischer hardness tester (HP100-XYp, manufactured by Fischer Instruments). As a measurement sample, a Blu-ray disc produced in the same manner as described above was used except that a hard coat layer was not provided. As a measuring method, a load of 1000 mN was applied for 60 seconds, then the weight was removed (0 mN), and the indentation depth (the deepest indentation depth) immediately after the weight was removed (0 mN) was measured (25 ° C., 45% RH). ). The unit is ⁇ m.
  • Initial warpage test The initial warpage was evaluated by measuring the difference between the warpage of the substrate before application of the UV curable resin composition of the example or the comparative example and the warpage after application and curing.
  • Initial warpage variation Warpage after curing-Warpage of substrate before application of UV curable resin composition ⁇ ... Less than ⁇ 0.6 degrees ⁇ ... ⁇ 0.6 or more
  • Durability warpage is the warpage of the substrate before application of the UV curable resin composition of the example or comparative example, and warpage after environmental test (80 ° C., 85% RH (relative humidity) environment after application and curing). Below, after leaving for 250 hours, the difference (the value calculated
  • Initial warpage change Warpage after environmental test-Warpage of substrate before application of UV curable resin composition ⁇ ⁇ ⁇ ⁇ less than ⁇ 0.6 degrees ⁇ ⁇ ⁇ ⁇ ⁇ 0.6 or more
  • a polycarbonate substrate having a diameter of 12 cm and a thickness of 1.1 mm having a guide groove with a track pitch of 0.32 ⁇ m is placed on a spin table, and a circular cap treatment is performed so as to cover the inner diameter of 11.5 mm.
  • the curable resin composition was supplied onto a cap at the center of 3.0 g.
  • Spin coating was performed at a speed range of 900 rpm for 4 to 7 seconds, and the coating film thickness was 95 ⁇ m.
  • the xenon flash lamp is irradiated for 2 shots just before the end of spin coating and cured to such an extent that the surface fluidity is lost.
  • the curable resin composition was completely cured.
  • the cured coating film (weight: W1) peeled from the polycarbonate substrate was refluxed in methyl ethyl ketone at 80 ° C. for 9 hours, dried at 80 ° C. for 4 hours, weighed (weight: W2), and the gel fraction was measured.
  • Gel fraction W2 ⁇ 100 / W1
  • the Tg temperature is high because the temperature is high in the viewpoint of adapting to the use environment, in particular, in a high temperature period such as summer time or in a normal state where it is stored at a higher temperature than normally assumed. Higher than that of Example 2, Example 1 is more preferable, Example 8 is more preferable, Examples 4 to 7 having Tg of 50 ° C. or higher are more preferable, and Tg is 60 ° C. or higher. Examples 4, 5 and 7 are most preferred. In addition to the value of Tg, the elastic modulus at 50 ° C. (50 ° C.
  • E, Mpa satisfies the current required level if it is 35 Mpa or more, preferably 45 Mpa or more, more preferably 100 Mpa or more, More preferably, it is 300 Mpa or more, Most preferably, it is 450 Mpa or more. Also, if both the amount of change in initial warpage and the amount of change in warpage after endurance testing are within the required tolerances, the current request will be covered for the time being. In the sense of decreasing, both values are preferably 0.5 or less, and more preferably 0.4 or less. In the hardness test, the value in Table 1 is preferably 54 or less, more preferably 51 or less, and most preferably 40 or less.
  • the restoring value is preferably 4 or more, more preferably 5 or more, and further preferably 6 or more.
  • the resin compositions of the above examples of the present invention give a cured product having excellent curability, high Tg, and high elastic modulus at 50 ° C., and when applied to a Blu-ray Disc, the amount of change in warping upon curing. There are few.
  • the curable resin composition of the present invention can be a Blu-ray disc having the above-mentioned excellent properties by forming a cured product layer (preferably a light transmitting layer) on the Blu-ray disc.

Abstract

The present invention relates to an ultraviolet curable resin composition for Blu-ray Discs and a Blu-ray Disc having a layer of a cured product formed from said composition. The resin composition contains an epoxy (meta) acrylate "A" obtained by reacting a glycidyl ether epoxy compound with a (meta) acrylate compound having a carboxy group, such as a (meta) acrylic acid, a monofunctional (meta) acrylate compound "B", and a photoinitiator "C". The content of "A" is greater than or equal to 30 parts by weight based on 100 parts by weight of the total resin composition, and when the content for "A" is regarded as "A" and the content for "B" is regarded as "B", A/B ranges from 0.8 to 1.45. A cured product produced from the resin composition has both a high glass transition temperature and a high modulus of elasticity at 50 degrees Celsius, and the restoring property after pressing is good. A Blu-ray Disc having a layer of the cured product has small variation in both warping from curing and warping after an endurance test.

Description

紫外線硬化型樹脂組成物及びブルーレイディスクUV curable resin composition and Blu-ray Disc
　本発明は、少なくとも光反射層と光透過層とが形成され、前記光透過層を通して３７０ｎｍ～４３０ｎｍの範囲内に発振波長を有するブルーレーザーにより記録又は再生を行う光ディスクにおける樹脂硬化物層、好ましくは光透過層に使用する紫外線硬化型樹脂組成物、及び、該紫外線硬化型樹脂組成物の硬化物層を、好ましくは光透過層として使用した光ディスクに関する。 The present invention provides a cured resin layer in an optical disc in which at least a light reflection layer and a light transmission layer are formed, and recording or reproduction is performed with a blue laser having an oscillation wavelength within a range of 370 nm to 430 nm through the light transmission layer, The present invention relates to an ultraviolet curable resin composition used for a light transmissive layer and an optical disk using a cured product layer of the ultraviolet curable resin composition, preferably as a light transmissive layer.
　近年、情報技術や情報網の発展により大容量の情報記録の伝達が頻繁に行われるようになっている。これに伴い、大容量となる映像、音楽、コンピューターデータ等を記録及び再生出来る高密度大容量の光ディスクが要求されている。高密度記録媒体として普及しているＤＶＤ（Digital　Versatile　Disc）では、高密度化を達成するため、ＣＤ（Compact　Disc）に比べ短波長の６５０ｎｍのレーザーを用い、光学系も高開口数化している。しかし、ＨＤＴＶ（High　Definition　Television）に対応した高画質の映像等を記録または再生する為には更なる高密度化が必要である。そのため、ＤＶＤの次世代に位置する更なる高密度記録の方法及びその光ディスクの検討が行われている。例えば、ＤＶＤよりも更に短波長のブルーレーザーの光学系を用いる新しい光ディスク構造による高密度記録方式が提案されている。 In recent years, with the development of information technology and information networks, large-capacity information records are frequently transmitted. Accordingly, a high-density and large-capacity optical disk capable of recording and reproducing large-capacity video, music, computer data, and the like is required. DVD (Digital Versatile Disc), which is popular as a high-density recording medium, uses a 650 nm laser with a shorter wavelength than CD (Compact Disc) to achieve higher density, and the optical system has a higher numerical aperture. . However, it is necessary to further increase the density in order to record or play back high-definition video corresponding to HDTV (High Definition Television). Therefore, further high density recording methods and optical discs for the next generation of DVD are being studied. For example, a high-density recording method using a new optical disk structure using an optical system of a blue laser having a shorter wavelength than that of a DVD has been proposed.
　この新しい光ディスクはポリカーボネート等のプラスチックで形成される透明又は不透明の基板にピットや情報記録層等の情報記録部位を形成し、次いで情報記録部位上に約１００μｍの光透過層を積層した構造を有している。該光ディスクにおいては、記録光又は再生光が、あるいはその両方が該光透過層に入射する構造となっている。この光ディスクの光透過層には、生産性の観点から、紫外線硬化型樹脂組成物を使用することがもっぱら研究されている。 This new optical disc has a structure in which an information recording site such as a pit or an information recording layer is formed on a transparent or opaque substrate made of plastic such as polycarbonate, and then a light transmission layer of about 100 μm is laminated on the information recording site. is doing. The optical disk has a structure in which recording light and / or reproducing light is incident on the light transmission layer. From the viewpoint of productivity, the use of an ultraviolet curable resin composition for the light transmission layer of this optical disc has been studied exclusively.
　このような、ブルーレーザーにより記録又は再生を行う光ディスク（本明細書においては、ブルーレイディスク又はＢＤともいう）においては、ＤＶＤに用いられる光透過層に比して、ＢＤの光透過層は、厚膜であり、またＤＶＤ－９構造の中間層として用いられる場合と異なり、表層あるいは表層近傍に光透過層が設けられる。このため、従来ＤＶＤに好適に用いられている光ディスク用紫外線硬化型樹脂組成物をそのまま転用しても、歪みや光反射層の腐食等による記録再生の信頼性低下がＤＶＤよりも顕著に生じる場合がある。更に、短波長の光を長期に亘って安定して透過する光透過性や、表層や表層近傍に用いられるため高い硬度を有する必要があり、また生産性の問題から厚膜を好適に作成できる組成物であることも求められる。 In such an optical disc that records or reproduces with a blue laser (also referred to as a Blu-ray disc or a BD in this specification), the light transmission layer of the BD is thicker than the light transmission layer used in a DVD. Unlike the case where it is a film and used as an intermediate layer of a DVD-9 structure, a light transmission layer is provided on the surface layer or in the vicinity of the surface layer. For this reason, even if the UV curable resin composition for optical discs that has been suitably used for conventional DVDs is used as it is, the reliability of recording and reproduction is significantly lower than that for DVDs due to distortion, corrosion of the light reflection layer, etc. There is. Furthermore, it is necessary to have a high hardness because it is used in the surface layer or in the vicinity of the surface layer, and a thick film can be suitably produced from the problem of productivity. It is also required to be a composition.
　光ディスクの反りを小さくできる紫外線硬化型樹脂組成物として、例えば、水酸基含有（メタ）アクリレートにラクトン化合物を反応させて得られるモノマーと、ポリイソシアネート化合物とを反応させて得られるウレタン（メタ）アクリレートを含有する紫外線硬化型樹脂組成物が開示されている（特許文献１参照）。当該紫外線硬化型樹脂組成物は、比較的柔軟性に優れたウレタン（メタ）アクリレートを使用することにより低硬化収縮率かつ低粘度の保護コート剤として有用な紫外線硬化型樹脂組成物である。しかし、当該組成物はＢＤ用の光透過層とするには粘度が低いため、厚膜の形成が困難であった。また、粘度を向上させるため、ウレタン（メタ）アクリレートの含有量を増加させて光ディスクの光透過層を形成した場合には、高温高湿環境下において金属膜の腐食等による劣化が生じる問題があった。 As an ultraviolet curable resin composition capable of reducing warpage of an optical disk, for example, urethane (meth) acrylate obtained by reacting a lactone compound with a hydroxyl group-containing (meth) acrylate and a polyisocyanate compound is used. The ultraviolet curable resin composition to contain is disclosed (refer patent document 1). The ultraviolet curable resin composition is an ultraviolet curable resin composition useful as a protective coating agent having a low curing shrinkage and a low viscosity by using urethane (meth) acrylate having relatively excellent flexibility. However, since the composition has a low viscosity for a light transmission layer for BD, it is difficult to form a thick film. In addition, when the light transmission layer of the optical disk is formed by increasing the content of urethane (meth) acrylate in order to improve the viscosity, there is a problem that deterioration due to corrosion of the metal film occurs in a high temperature and high humidity environment. It was.
　また、歪みが小さく、靭性、耐熱性に優れる組成物として、ウレタン（メタ）アクリレート、エポキシ（メタ）アクリレートを含有する樹脂組成物が開示されている（特許文献２参照）。当該組成物は、ウレタン（メタ）アクリレートを一定量以上、紫外線硬化型樹脂組成物中に含有させることにより硬化時の歪みを抑え、靭性を付与しているが、ウレタン（メタ）アクリレートは温度変化、湿度変化による反りの変化の影響を受けやすいものであるため、記録媒体が保存された環境において湿度または温度変化が生じた場合には、記録媒体の信頼性低下を招く問題があった。
　さらに、従来の紫外線硬化型樹脂組成物の硬化物を備える光記録媒体においては、ウレタン（メタ）アクリレートを一定量以上含有させて歪みを抑えていたため、保管される環境に制約があった。即ち、反りの変化量が小さい紫外線硬化型樹脂組成物の硬化物を備える記録媒体は温度変化による影響を受けやすいため、夏場などの高温環境下（３０℃～４０℃）において、反りの変化量が大きくなる問題が生じていた。またハードコート層が備えられていない場合には夏場の高温環境下での保管・管理下において、光記録媒体同士が紫外線硬化型樹脂組成物により接着する懸念があった。 Moreover, the resin composition containing urethane (meth) acrylate and epoxy (meth) acrylate is disclosed as a composition with small distortion and excellent toughness and heat resistance (see Patent Document 2). The composition contains a certain amount or more of urethane (meth) acrylate in the ultraviolet curable resin composition to suppress distortion during curing and impart toughness, but urethane (meth) acrylate changes in temperature. Since it is easily affected by a change in warpage due to a change in humidity, there has been a problem that the reliability of the recording medium is reduced when a change in humidity or temperature occurs in an environment where the recording medium is stored.
Furthermore, in an optical recording medium provided with a cured product of a conventional ultraviolet curable resin composition, a certain amount or more of urethane (meth) acrylate is contained to suppress distortion, and thus the storage environment is restricted. That is, since a recording medium provided with a cured product of an ultraviolet curable resin composition with a small amount of warpage is easily affected by temperature changes, the amount of warpage changes in a high temperature environment (30 ° C. to 40 ° C.) such as summer. There has been a problem of increasing. Further, when the hard coat layer is not provided, there is a concern that the optical recording media adhere to each other with the ultraviolet curable resin composition under storage and management in a high temperature environment in summer.
　一方、弾性率の高い紫外線硬化型樹脂組成物として、エポキシ（メタ）アクリレートを含有する樹脂組成物が開示されている（特許文献３参照）。しかし、エポキシ（メタ）アクリレートは、硬化時の反りが極めて大きく、柔軟性を付与する成分がなければ、信頼性に優れる記録媒体を得ることはできない。しかし、柔軟性を付与する成分としてウレタン（メタ）アクリレートを使用した場合には、上記の問題により信頼性の低下、高温環境下（３０℃～４０℃）での保管の弊害を招いてしまう。従って、従来の紫外線硬化型樹脂組成物を用いる場合には、膜厚の紫外線硬化型樹脂硬化物層を有する光ディスクにおいては、信頼性を低下させることなく、反りを低減することが困難であった。 On the other hand, a resin composition containing epoxy (meth) acrylate is disclosed as an ultraviolet curable resin composition having a high elastic modulus (see Patent Document 3). However, the epoxy (meth) acrylate has a very large warp upon curing, and a recording medium with excellent reliability cannot be obtained without a component that imparts flexibility. However, when urethane (meth) acrylate is used as a component for imparting flexibility, the above-described problems cause a decrease in reliability and an adverse effect on storage in a high temperature environment (30 ° C. to 40 ° C.). Therefore, in the case of using the conventional ultraviolet curable resin composition, it is difficult to reduce the warp without reducing the reliability in the optical disk having the ultraviolet curable resin cured material layer having a film thickness. .
　これまで、光ディスクの要求特性を満たすように、耐久性や接着力といった特定の物性に着目して調整された紫外線硬化型樹脂組成物が様々提案されてきたが（特許文献４～８）、硬化時の反りを低く抑えつつ、硬化物として温度変化、湿度変化による反りの変化量が少ない、信頼性に優れた紫外線硬化型樹脂であって、高温環境下においても安定して保管ができる紫外線硬化型樹脂組成物の硬化物を備えたブルーレイディスクは見出されていなかった。そこで、市場で求められる、当該要求特性を満たす樹脂の開発が強く望まれていた。 Until now, various ultraviolet curable resin compositions have been proposed that are adjusted by paying attention to specific physical properties such as durability and adhesive strength so as to satisfy the required characteristics of optical disks (Patent Documents 4 to 8). Ultraviolet curable resin with excellent reliability and low warpage at the same time, with little change in warpage due to temperature and humidity changes as a cured product, and can be stored stably even in high temperature environments A Blu-ray disc provided with a cured product of the mold resin composition has not been found. Therefore, development of a resin that satisfies the required characteristics required in the market has been strongly desired.
特開平１１－１２４９５号公報Japanese Patent Laid-Open No. 11-12495 特開２００７－１６９４５０号公報JP 2007-169450 A 特開２００９－２６６３５５号公報JP 2009-266355 A 特開２００５－２４３１０９号公報JP-A-2005-243109 特開２００６－２４９２２８号公報JP 2006-249228 A 特開２００９－３２３０２号公報JP 2009-32302 A 特開２００９－３２３０３号公報JP 2009-32303 A 国際公開第２００８／０９９６６６号International Publication No. 2008/099666
　本発明が解決しようとする課題は、硬化した場合、ガラス転移温度（Ｔｇ）が一定以上に高く且つ、弾性率が高い硬化物を与え、かつ、光ディスクに適用した場合、硬化時の反りが少ない紫外線硬化型樹脂組成物であり、更に、湿度変化または温度変化が生じた場合、即ち、高温高湿の環境下に保存された場合においても反りの変化量の少ない、信頼性に優れる硬化物層を形成することが出来る該樹脂組成物の提供、及び、該樹脂組成物の硬化物層を有し、耐久性に優れ、高温環境下でも安定して保管でき、反りの変化量の少ない信頼性に優れる光ディスク、好ましくはブルーレイディスクを提供することにある。 The problem to be solved by the present invention is that when cured, a glass transition temperature (Tg) is higher than a certain level and a cured product having a high elastic modulus is given, and when applied to an optical disc, there is little warping during curing. It is an ultraviolet curable resin composition, and further has a highly reliable cured layer with little change in warpage even when humidity change or temperature change occurs, that is, when it is stored in a high temperature and high humidity environment. Providing the resin composition capable of forming a resin, and having a cured layer of the resin composition, having excellent durability, being able to be stably stored in a high temperature environment, and having a small amount of change in warpage It is to provide an optical disc excellent in the quality, preferably a Blu-ray disc.
　本発明においては、エポキシ（メタ）アクリレートとして、グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレート、及び、単官能（メタ）アクリレート化合物を特定の比率で含有する組成物の硬化被膜を光ディスク（好ましくはブルーレイディスク）に、例えば光透過層等として適用することにより、湿度変化または温度変化による反りの変化量が少なく、かつ高温環境下においても安定的に保管できる光ディスクを提供できることを見出し本発明に至った。
　そして、このような湿度変化または温度変化による反りの変化量が少ない光ディスクは、反りによる光反射率の低下が生じにくく、信号特性の劣化が少ないため、短波長ブルーレーザーによる情報の記録・再生が良好であるため、ブルーレイディスクとして有用である。
　　なお、本明細書においては、「カルボキシ基を有する（メタ）アクリレート化合物」の語は、カルボキシ基と（メタ）アクリル基の両者を含む（メタ）アクリル化合物と同義の意味で使用する。従って、本明細書においては「カルボキシ基を有する（メタ）アクリレート化合物」には、（メタ）アクリル酸も含む。
　また、「（メタ）アクリル酸」の語は、アクリル酸及びメタクリル酸の何れか一方若しくは両者の意味で使用され、「（メタ）アクリレート」の語も、同様に、アクリレート及びメタクリレートの何れか一方若しくは両者の意味で使用される。 In the present invention, an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound and a (meth) acrylate compound having a carboxy group as an epoxy (meth) acrylate, and a monofunctional (meth) acrylate compound Is applied to an optical disc (preferably a Blu-ray disc) as, for example, a light transmission layer, etc., so that the amount of change in warpage due to humidity change or temperature change is small, and in a high temperature environment. The present invention has been found that an optical disc that can be stably stored can be provided.
In addition, optical discs with little change in warpage due to humidity change or temperature change are unlikely to cause a decrease in light reflectivity due to warpage and little deterioration in signal characteristics. Since it is good, it is useful as a Blu-ray Disc.
In the present specification, the term “(meth) acrylate compound having a carboxy group” is used in the same meaning as a (meth) acryl compound containing both a carboxy group and a (meth) acryl group. Therefore, in the present specification, “(meth) acrylate compound having a carboxy group” includes (meth) acrylic acid.
Further, the term “(meth) acrylic acid” is used to mean either or both of acrylic acid and methacrylic acid, and the term “(meth) acrylate” is similarly any one of acrylate and methacrylate. Or it is used in the meaning of both.
　本発明の好ましい態様は、基板上に、少なくとも光反射層と、光透過層とが積層され、前記光透過層側からブルーレーザーを入射して情報の再生を行う光ディスクの樹脂硬化物層（好ましくは光透過層）に使用する紫外線硬化型樹脂組成物、その硬化物、及び該樹脂組成物の硬化物層を有するブルーレイディスクである。 In a preferred embodiment of the present invention, at least a light reflection layer and a light transmission layer are laminated on a substrate, and a cured resin layer of an optical disk (preferably a blue laser is incident from the light transmission layer side to reproduce information) Is a Blu-ray disc having an ultraviolet curable resin composition used for the light transmission layer), a cured product thereof, and a cured product layer of the resin composition.
　即ち、本発明は、下記（１）～（１８）に関するものである。
（１）　ブルーレイディスク用紫外線硬化型樹脂組成物中に、（ｉ）グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）、（ｉｉ）単官能（メタ）アクリレート化合物（Ｂ）及び（ｉｉｉ）光重合開始剤（Ｃ）を含有し、該樹脂組成物の総量１００重量部に対する、前記エポキシ（メタ）アクリレート（Ａ）の含有割合が３０重量部以上であり、その含有割合をＡ重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合をＢ重量部とした時、Ａ／Ｂが０．８～１．４５である該樹脂組成物の硬化物層を有するブルーレイディスク。
（２）　グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物とを反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）、単官能（メタ）アクリレート化合物（Ｂ）及び光重合開始剤（Ｃ）を含有するブルーレイディスク用紫外線硬化型樹脂組成物であって、該樹脂組成物の総量１００重量部に対する、前記エポキシ（メタ）アクリレート（Ａ）の含有割合が３０重量部以上であり、その含有割合をＡ重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合をＢ重量部とした時、Ａ／Ｂが０．８～１．４５であるブルーレイディスク用紫外線硬化型樹脂組成物。
（３）　カルボキシ基を有する（メタ）アクリレート化合物が、（ａ）不飽和カルボン酸またはその誘導体、または、（ｂ）ヒドロキシ（メタ）アクリレート化合物のラクトン付加物（ｂ１）と多塩基酸無水物（ｂ２）から得られる化合物であることを特徴とする上記（２）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 That is, the present invention relates to the following (1) to (18).
(1) An epoxy (meth) acrylate (A) obtained by reacting (i) a glycidyl ether type epoxy compound and a (meth) acrylate compound having a carboxy group in an ultraviolet curable resin composition for Blu-ray Disc, (Ii) The monofunctional (meth) acrylate compound (B) and (iii) the photopolymerization initiator (C), the content of the epoxy (meth) acrylate (A) with respect to 100 parts by weight of the total amount of the resin composition When the ratio is 30 parts by weight or more, the content is A parts by weight, and the content of the monofunctional (meth) acrylate compound (B) is B parts by weight, the A / B is 0.8 to 1. A Blu-ray disc having a cured product layer of the resin composition of 45.
(2) Epoxy (meth) acrylate (A) obtained by reacting a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group, a monofunctional (meth) acrylate compound (B), and photopolymerization initiation An ultraviolet curable resin composition for Blu-ray Disc containing an agent (C), wherein the content of the epoxy (meth) acrylate (A) is 30 parts by weight or more with respect to 100 parts by weight of the total amount of the resin composition UV curing for Blu-ray discs with an A / B of 0.8 to 1.45, where the content is A parts by weight and the content of the monofunctional (meth) acrylate compound (B) is B parts by weight. Mold resin composition.
(3) The (meth) acrylate compound having a carboxy group is (a) an unsaturated carboxylic acid or a derivative thereof, or (b) a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride ( The ultraviolet curable resin composition for Blu-ray Discs as described in (2) above, which is a compound obtained from b2).
（４）　グリシジルエーテル型エポキシ化合物が、下記式（２）
式（２）
Figure JPOXMLDOC01-appb-I000001
（式中、ｎは０～２０の整数を示す。）
で表され、かつ、エポキシ当量が１８０ｇ／ｅｑ．～２００ｇ／ｅｑ．である液状グリシジルエーテル型エポキシ化合物であることを特徴とする上記（２）又は（３）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（５）　単官能（メタ）アクリレート化合物（Ｂ）がベンゼン環を有する（メタ）アクリレート化合物又はジシクロペンテニル基又はジシクロペンタジエン基を有する（メタ）アクリレート化合物である上記（２）～（４）の何れか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（６）　前記単官能（メタ）アクリレート化合物（Ｂ）として、下記式（１）
式（１）
Figure JPOXMLDOC01-appb-I000002
（式中、ｎは１～１０の整数を示す。）
で表される化合物を含有することを特徴とする上記（２）～（５）の何れか一項に記載の紫外線硬化型樹脂組成物。 (4) The glycidyl ether type epoxy compound has the following formula (2)
Formula (2)
Figure JPOXMLDOC01-appb-I000001
(In the formula, n represents an integer of 0 to 20.)
And an epoxy equivalent of 180 g / eq. ~ 200 g / eq. The ultraviolet curable resin composition for Blu-ray Discs according to (2) or (3) above, which is a liquid glycidyl ether type epoxy compound.
(5) The above (2) to (4), wherein the monofunctional (meth) acrylate compound (B) is a (meth) acrylate compound having a benzene ring or a (meth) acrylate compound having a dicyclopentenyl group or a dicyclopentadiene group The ultraviolet curable resin composition for Blu-ray Discs as described in any one of these.
(6) As said monofunctional (meth) acrylate compound (B), following formula (1)
Formula (1)
Figure JPOXMLDOC01-appb-I000002
(In the formula, n represents an integer of 1 to 10.)
The ultraviolet curable resin composition according to any one of (2) to (5) above, which comprises a compound represented by the formula:
（７）　前記式（１）においてｎが２である上記（６）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（８）　ブルーレイディスク用紫外線硬化型樹脂組成物の総量１００重量部に対する、式（１）で表される化合物の含有割合、又は、単官能（メタ）アクリレート化合物（Ｂ）として、式（１）で表される化合物と共に、更に、ジシクロペンテニルオキシエチル（メタ）アクリレートを含む場合はその両者の合計含有割合、をＢ１重量部とした時、Ａ／Ｂ１が０．８～１．４５である上記（６）又は（７）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（９）　更に、ウレタン（メタ）アクリレートを、前記紫外線硬化型樹脂組成物の総量１００重量部に対し、２０重量部以下の割合で含有することを特徴とする上記（２）～（８）の何れか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（１０）　エポキシ（メタ）アクリレート（Ａ）が、下記式（２）
Figure JPOXMLDOC01-appb-I000003
（式中ｎは１～１０の整数を示す）
で表されるグリシジルエーテル型エポキシ化合物と（メタ）アクリル酸とを反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）である上記（２）～（９）の何れか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 (7) The ultraviolet curable resin composition for Blu-ray Discs according to (6), wherein n is 2 in the formula (1).
(8) The content ratio of the compound represented by formula (1) or the monofunctional (meth) acrylate compound (B) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition for Blu-ray Disc, In the case where dicyclopentenyloxyethyl (meth) acrylate is further contained together with the compound represented by the formula (1), the total content of the two is B1 parts by weight, and A / B1 is 0.8 to 1.45. The ultraviolet curable resin composition for Blu-ray discs according to (6) or (7) above.
(9) The urethane (meth) acrylate is further contained in a proportion of 20 parts by weight or less with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition. The ultraviolet curable resin composition for Blu-ray Discs according to any one of the above.
(10) The epoxy (meth) acrylate (A) is represented by the following formula (2)
Figure JPOXMLDOC01-appb-I000003
(Where n represents an integer of 1 to 10)
The epoxy resin (meth) acrylate (A) obtained by reacting a glycidyl ether type epoxy compound represented by the formula (meth) acrylic acid with the glycidyl ether type epoxy compound represented by the above (2) to (9): UV curable resin composition for Blu-ray Disc.
（１１）　前記紫外線硬化型樹脂組成物の総量１００重量部に対して、エポキシ（メタ）アクリレート（Ａ）の含量割合Ａ重量部と前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合Ｂ重量部との合計が、少なくとも８０重量部である上記（２）～（１０）の何れか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（１２）ブルーレイディスク用紫外線硬化型樹脂組成物の硬化物のガラス転移温度Ｔｇが少なくとも４０℃である上記（２）～（１１）の何れか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（１３）　ブルーレイディスク用紫外線硬化型樹脂組成物に紫外線を照射し、紫外線照射後に形成される硬化物の５０℃における弾性率が４５０～１５００ＭＰａである上記（２）～（１２）のいずれか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（１４）　上記（１）～（１３）のいずれか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物を硬化した硬化物。
（１５）　上記（１）～（１３）のいずれか一項に記載の紫外線硬化型樹脂組成物に活性エネルギー線を照射して得られる硬化物。
（１６）　光ディスク基板に、上記（１）～（１３）のいずれか一項に記載の紫外線硬化型樹脂組成物を塗布し、活性エネルギー線を照射して得られる光透過層を有するブルーレイディスク。
（１７）　光ディスク基板が、反射層を有する光ディスク基板である上記（１６）に記載のブルーレイディスク。
（１８）　上記（１４）に記載の硬化物のガラス転移温度Ｔｇが少なくとも４０℃で、該硬化物の層を有するブルーレイディスクの初期の反りの変化量、及び、８０℃で、相対湿度８５％の環境下に２５０時間曝した後の耐久試験後の反りの変化量の両者の値が、何れも±０．６度未満である上記（１６）又は（１７）に記載のブルーレイディスク。 (11) The content ratio B weight of the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound (B) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition The ultraviolet curable resin composition for Blu-ray Discs according to any one of the above (2) to (10), wherein the total amount is at least 80 parts by weight.
(12) The ultraviolet curable resin composition for Blu-ray Disc according to any one of (2) to (11) above, wherein the cured product of the ultraviolet curable resin composition for Blu-ray Disc has a glass transition temperature Tg of at least 40 ° C. object.
(13) The ultraviolet curable resin composition for Blu-ray Disc is irradiated with ultraviolet rays, and the cured product formed after the ultraviolet irradiation has an elastic modulus at 50 ° C. of 450 to 1500 MPa, any one of (2) to (12) Item 4. An ultraviolet curable resin composition for Blu-ray Discs according to the item.
(14) A cured product obtained by curing the ultraviolet curable resin composition for Blu-ray disc according to any one of (1) to (13).
(15) A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of (1) to (13) with active energy rays.
(16) A Blu-ray disc having a light transmission layer obtained by applying the ultraviolet curable resin composition according to any one of (1) to (13) above to an optical disc substrate and irradiating with active energy rays.
(17) The Blu-ray disc according to (16), wherein the optical disc substrate is an optical disc substrate having a reflective layer.
(18) The glass transition temperature Tg of the cured product according to the above (14) is at least 40 ° C., the amount of initial warpage of the Blu-ray disc having the cured product layer, and the relative humidity of 85% at 80 ° C. The Blu-ray disc as described in (16) or (17) above, wherein both values of the amount of change in warpage after the durability test after exposure for 250 hours in the above environment are both less than ± 0.6 degrees.
　本発明のブルーレイディスク用紫外線硬化型樹脂組成物（以下、本発明の紫外線硬化型樹脂組成物、又は、本発明の樹脂組成物ともいう）は、硬化したとき、高いガラス転移点（Ｔｇ）、高い弾性率を有し、復元性も良好な硬化物を与えることが出来る。また、該樹脂組成物をブルーレイディスクに適用した時、硬化時の反りが少なく、優れた硬化性を有し、湿度変化、温度変化により反りの変化量が抑制された硬化被膜を形成することができる。また、本発明の紫外線硬化型樹脂組成物の硬化物層を備える光ディスク（好ましくはブルーレイディスク）は硬化時及び耐久試験後の反りの変化量が小さく、信頼性の高い光ディスクであり、高温環境下（３０℃～４０℃）での保管を行い易い。 The ultraviolet curable resin composition for Blu-ray Disc of the present invention (hereinafter also referred to as the ultraviolet curable resin composition of the present invention or the resin composition of the present invention) has a high glass transition point (Tg) when cured. A cured product having a high elastic modulus and good recoverability can be obtained. In addition, when the resin composition is applied to a Blu-ray disc, it can form a cured film that has less warpage during curing, has excellent curability, and has reduced warpage change due to changes in humidity and temperature. it can. In addition, an optical disc (preferably a Blu-ray disc) provided with a cured product layer of the ultraviolet curable resin composition of the present invention is a highly reliable optical disc with a small amount of change in warpage during curing and after an endurance test, and in a high temperature environment. Easy to store at (30 ℃ ~ 40 ℃).
　本発明の紫外線硬化型樹脂組成物は、単官能（メタ）アクリレート（Ｂ）、及び、グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）、の少なくとも両者を特定割合において含有する。即ち、本発明の紫外線硬化型樹脂組成物の総量１００重量部に対して、エポキシ（メタ）アクリレート（Ａ）を３０重量部以上含有し、かつ、その含量割合をＡ重量部とし、単官能（メタ）アクリレート（Ｂ）の含有量を、Ｂ重量部とすると、Ａ／Ｂが０．８～１．４５となる範囲で、上記両者を含有する。該Ａ／Ｂの好ましい範囲は、０．８～１．３であり、更に、好ましくは０．８～１．１である The ultraviolet curable resin composition of the present invention is an epoxy (meth) obtained by reacting a monofunctional (meth) acrylate (B) and a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group. At least both of acrylate (A) are contained in a specific ratio. That is, 30 parts by weight or more of epoxy (meth) acrylate (A) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition of the present invention, and the content ratio is A part by weight. When the content of the (meth) acrylate (B) is B parts by weight, both of the above are contained within a range where A / B is 0.8 to 1.45. The preferred range of A / B is 0.8 to 1.3, more preferably 0.8 to 1.1.
　本発明の紫外線硬化型樹脂組成物において用いる、単官能（メタ）アクリレートとしては、特に制限は無いが、具体的には、下記する単官能（メタ）アクリレートが好ましい。
　単官能（メタ）アクリレートとしては、イソオクチル（メタ）アクリレート、イソアミル（メタ）アクリレート、ラウリル（メタ）アクリレート、イソデシル（メタ）アクリレート、ステアリル（メタ）アクリレート、セチル（メタ）アクリレート、イソミリスチル（メタ）アクリレート、トリデシル（メタ）アクリレート等のＣ５～Ｃ２０（好ましくはＣ７～Ｃ１８）アルキル（メタ）アクリレート；ベンジル（メタ）アクリレート、フェニルグリシジル（メタ）アクリレート、ポリプロピレンオキサイド変性ノニルフェニル（メタ）アクリレート、前記式（１）で表されるフェノキシエチルアクリレート等のベンゼン環を有する（メタ）アクリレート化合物；テトラヒドロフルフリル（メタ）アクリレート、モルホリン（メタ）アクリレート等のヘテロ環を有する（メタ）アクリレート；２－ヒドロキシプロピル（メタ）アクリレート等の水酸基を有するＣ２～Ｃ８アルキル（メタ）アクリレート；エトキシジエチレングリコール（メタ）アクリレート、ポリプロピレングリコール（メタ）アクリレート等のポリアルキレングリコール（メタ）アクリレート；トリシクロデカン（メタ）アクリレート、イソボルニル（メタ）アクリレート、ジシクロペンタジエンオキシエチル（メタ）アクリレート、ジシクロペンテニルアクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１１Ａ）、ジシクロペンテニルオキシエチルアクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１２Ａ）、ジシクロペンテニルオキシエチルメタクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１２Ｍ）、ジシクロペンタニルアクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１３Ａ）、ジシクロペンタニルメタクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１３Ｍ）、１－アダマンチルアクリレート（例えば、出光興産株式会社製Ａｄａｍａｎｔａｔｅ　ＡＡ）、２－メチル－２－アダマンチルアクリレート（例えば、出光興産株式会社製Ａｄａｍａｎｔａｔｅ　ＭＡ）、２－エチル－２－アダマンチルアクリレート（例えば、出光興産株式会社製Ａｄａｍａｎｔａｔｅ　ＥＡ）、１－アダマンチルメタクリレート（例えば、出光興産株式会社製Ａｄａｍａｎｔａｔｅ　ＡＭ）等のＣ７～Ｃ１０脂肪族環を有する（メタ）アクリレート化合物；エチレンオキサイド変性フェノキシ化リン酸（メタ）アクリレート、エチレンオキサイド変性ブトキシ化リン酸（メタ）アクリレート及びエチレンオキサイド変性オクチルオキシ化リン酸（メタ）アクリレート等のリン酸（メタ）アクリレート；等を挙げることができる。 Although there is no restriction | limiting in particular as monofunctional (meth) acrylate used in the ultraviolet curable resin composition of this invention, Specifically, the monofunctional (meth) acrylate mentioned below is preferable.
Monofunctional (meth) acrylates include isooctyl (meth) acrylate, isoamyl (meth) acrylate, lauryl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, cetyl (meth) acrylate, and isomyristyl (meth) C5 to C20 (preferably C7 to C18) alkyl (meth) acrylate such as acrylate and tridecyl (meth) acrylate; benzyl (meth) acrylate, phenylglycidyl (meth) acrylate, polypropylene oxide modified nonylphenyl (meth) acrylate, the above formula (Meth) acrylate compounds having a benzene ring such as phenoxyethyl acrylate represented by (1); tetrahydrofurfuryl (meth) acrylate, morpholine (meth) acrylate (Meth) acrylates having a heterocycle such as 2-hydroxypropyl (meth) acrylate, etc., and C2-C8 alkyl (meth) acrylates having a hydroxyl group, such as ethoxydiethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, etc. Alkylene glycol (meth) acrylate; tricyclodecane (meth) acrylate, isobornyl (meth) acrylate, dicyclopentadieneoxyethyl (meth) acrylate, dicyclopentenyl acrylate (for example, FANCYL FA-511A manufactured by Hitachi Chemical Co., Ltd.), Dicyclopentenyloxyethyl acrylate (for example, FANCYL FA-512A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenyloxyethyl methacrylate (for example, For example, FANCYL FA-512M manufactured by Hitachi Chemical Co., Ltd., dicyclopentanyl acrylate (for example, FANCYL FA-513A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentanyl methacrylate (for example, FANCYL FA manufactured by Hitachi Chemical Co., Ltd.) -513M), 1-adamantyl acrylate (eg, Adamantate AA manufactured by Idemitsu Kosan Co., Ltd.), 2-methyl-2-adamantyl acrylate (eg, Adamantate MA manufactured by Idemitsu Kosan Co., Ltd.), 2-ethyl-2-adamantyl acrylate (eg, (Adamantate EA manufactured by Idemitsu Kosan Co., Ltd.), 1-adamantyl methacrylate (for example, Adamantate AM manufactured by Idemitsu Kosan Co., Ltd.) and the like (meth) acrylated having a C7 to C10 aliphatic ring Compound; phosphoric acid (meth) acrylates such as ethylene oxide modified phenoxylated phosphoric acid (meth) acrylate, ethylene oxide modified butoxylated phosphoric acid (meth) acrylate and ethylene oxide modified octyloxylated phosphoric acid (meth) acrylate; Can be mentioned.
　上記の中で好ましい単官能（メタ）アクリレートとしては、前記式（１）で表されるフェノキシエチルアクリレート、ベンジル（メタ）アクリレート、フェニルグリシジル（メタ）アクリレート、ポリプロピレンオキサイド変性ノニルフェニル（メタ）アクリレート、等のベンゼン環を有する（メタ）アクリレート化合物、ジシクロペンタジエンオキシエチル（メタ）アクリレート、ジシクロペンテニルアクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１１Ａ）、ジシクロペンテニルオキシエチルアクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１２Ａ）、ジシクロペンテニルオキシエチルメタクリレート（例えば、日立化成工業株式会社製ＦＡＮＣＲＹＬ　ＦＡ－５１２Ｍ）等のジシクロペンテニル基又はジシクロペンタジエン基を有する（メタ）アクリレート化合物が好ましい。中でも、ジシクロペンテニルオキシエチルアクリレート、または下記式（１）で表される（メタ）アクリレート化合物が好ましい。
　（メタ）アクリロイル基を１つ有する単官能（メタ）アクリレート化合物は本発明の紫外線硬化型樹脂組成物を光透過層として形成させた光ディスクの機械的特性（反り、ゆがみ等の抑制）を向上させる機能を有する。
　従って、本発明の好ましい態様として、該単官能（メタ）アクリレート化合物として、下記式（１）で表される化合物及びジシクロペンテニルオキシエチル（メタ）アクリレートの何れか一方又は両者を含む場合を挙げることが出来る。また、より好ましい態様として、下記式（１）で表される化合物を含む態様を挙げることが出来る。この場合、本発明の樹脂組成物の総量１００重量部に対する、下記式（１）で表される化合物及びジシクロペンテニルオキシエチル（メタ）アクリレートの何れか一方又は両者の合計の含量割合をＢ１重量部とするとき、Ａ／Ｂ１が０．８～１．４５であるとき、より好ましく、更に好ましくは０．８～１．３であり、特に好ましくは０．８～１．１である。この場合においては、下記式（１）で表される化合物又は／及びジシクロペンテニルオキシエチル（メタ）アクリレート成分の効力が充分に発揮される。
　上記の場合において、単官能（メタ）アクリレート（Ｂ）として、下記式（１）で表される化合物又は／及びジシクロペンテニルオキシエチル（メタ）アクリレート以外の他の単官能（メタ）アクリレートを含まなくても良いが、必要に応じて含んでいても良い。単官能（メタ）アクリレート（Ｂ）の総量１００重量部に対する、式（１）で表される化合物又は／及びジシクロペンテニルオキシエチル（メタ）アクリレートの好ましい含量は、５０～１００重量部であり、好ましくは８０～１００重量部であり、より好ましくは９０～１００重量部であり、更に、好ましくは、９５～１００重量部である。残部は該他の単官能（メタ）アクリレートである。
　該他の単官能（メタ）アクリレートを含む場合、場合によってはＡ／Ｂが０．８～１．４５の範囲から外れても、本願発明の効果を達成することができる場合があり、そのような場合は本発明の範囲に入る。 Preferred monofunctional (meth) acrylates among the above include phenoxyethyl acrylate represented by the above formula (1), benzyl (meth) acrylate, phenylglycidyl (meth) acrylate, polypropylene oxide-modified nonylphenyl (meth) acrylate, (Meth) acrylate compounds having a benzene ring such as dicyclopentadieneoxyethyl (meth) acrylate, dicyclopentenyl acrylate (for example, FANCYL FA-511A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenyloxyethyl acrylate (for example, Dicyclope such as FANCYL FA-512A manufactured by Hitachi Chemical Co., Ltd.) and dicyclopentenyloxyethyl methacrylate (for example, FANCYL FA-512M manufactured by Hitachi Chemical Co., Ltd.) Thenyl have groups or dicyclopentadiene group (meth) acrylate compounds are preferred. Among these, dicyclopentenyloxyethyl acrylate or a (meth) acrylate compound represented by the following formula (1) is preferable.
A monofunctional (meth) acrylate compound having one (meth) acryloyl group improves the mechanical properties (suppression of warpage, distortion, etc.) of an optical disk formed with the ultraviolet curable resin composition of the present invention as a light transmission layer. It has a function.
Accordingly, as a preferred embodiment of the present invention, a case where the monofunctional (meth) acrylate compound includes one or both of a compound represented by the following formula (1) and dicyclopentenyloxyethyl (meth) acrylate is exemplified. I can do it. Moreover, as a more preferable aspect, the aspect containing the compound represented by following formula (1) can be mentioned. In this case, the total content ratio of one or both of the compound represented by the following formula (1) and dicyclopentenyloxyethyl (meth) acrylate with respect to 100 parts by weight of the total amount of the resin composition of the present invention is B1 weight. In terms of parts, A / B1 is preferably 0.8 to 1.45, more preferably 0.8 to 1.3, and particularly preferably 0.8 to 1.1. In this case, the efficacy of the compound represented by the following formula (1) and / or dicyclopentenyloxyethyl (meth) acrylate component is sufficiently exhibited.
In the above case, the monofunctional (meth) acrylate (B) includes a compound represented by the following formula (1) and / or a monofunctional (meth) acrylate other than dicyclopentenyloxyethyl (meth) acrylate It does not have to be, but may be included as necessary. A preferred content of the compound represented by the formula (1) and / or dicyclopentenyloxyethyl (meth) acrylate with respect to 100 parts by weight of the total amount of the monofunctional (meth) acrylate (B) is 50 to 100 parts by weight, The amount is preferably 80 to 100 parts by weight, more preferably 90 to 100 parts by weight, and still more preferably 95 to 100 parts by weight. The balance is the other monofunctional (meth) acrylate.
When the other monofunctional (meth) acrylate is included, the effect of the present invention may be achieved even if A / B is out of the range of 0.8 to 1.45. In this case, it falls within the scope of the present invention.
　本発明において使用することができる単官能（メタ）アクリレート（Ｂ）において、特に好適な化合物として下記式（１）
Figure JPOXMLDOC01-appb-I000004
（式中、ｎは１～１０の整数を示す。）
で表される化合物を使用することができる。ここで、上記式（１）において、ｎは１～３が好ましい。使用する上記式（１）で表される化合物としては、具体的にはエチレンオキサイド変性フェノール（メタ）アクリレートが挙げられる。該化合物は市場より入手することが可能である。製品としては具体的にはＰｈｏｔｏｍｅｒ４０３５（例えば、コグニス株式会社製）、ＥＢＥＣＲＹＬ１１０（例えば、ダイセル・サイテック株式会社製）等が挙げられる。
　ここで、復元性を向上させ、硬化時の反りを低減させる観点からは上記式（１）においてｎが１又は２である化合物がより好ましく、更に好ましくはｎが２である化合物である。なお、上記式（１）の化合物において、高い復元性を付与し、硬化時の反りを低減させるために、より好ましい態様はｎ＝２の化合物を単独で使用するか、又は、ｎ＝１の化合物を、ｎ＝２の化合物と同量以下において併用する態様であり、更に好ましい態様はｎ＝２の化合物を単独で使用する態様である。即ち、紫外線樹脂組成物中における上記式（１）で表される化合物の、ｎ＝２の化合物に対する、ｎ＝１の化合物の含有割合を、下記の式で示すように、０～１の範囲内とすることがより好ましい。
式：（上記式（１）においてｎ＝１の化合物）／（上記式（１）においてｎ＝２の化合物）＝０～１．０ In the monofunctional (meth) acrylate (B) that can be used in the present invention, the following formula (1) is particularly preferable as a compound.
Figure JPOXMLDOC01-appb-I000004
(In the formula, n represents an integer of 1 to 10.)
The compound represented by these can be used. Here, in the above formula (1), n is preferably 1 to 3. Specific examples of the compound represented by the formula (1) to be used include ethylene oxide-modified phenol (meth) acrylate. The compound can be obtained from the market. Specific examples of the product include Photomer 4035 (for example, manufactured by Cognis Co., Ltd.), EBECRYL110 (for example, manufactured by Daicel Cytec Co., Ltd.), and the like.
Here, from the viewpoint of improving restorability and reducing warpage during curing, a compound in which n is 1 or 2 in the formula (1) is more preferable, and a compound in which n is 2 is more preferable. In addition, in the compound of the above formula (1), in order to impart high resilience and reduce warping during curing, a more preferred embodiment is to use a compound of n = 2 alone, or n = 1 This is an embodiment in which the compound is used in the same amount or less as the compound of n = 2, and a more preferred embodiment is an embodiment in which the compound of n = 2 is used alone. That is, the content ratio of the compound of n = 1 to the compound of n = 2 in the compound represented by the above formula (1) in the ultraviolet resin composition is in the range of 0 to 1 as shown in the following formula. It is more preferable to use the inside.
Formula: (compound with n = 1 in the above formula (1)) / (compound with n = 2 in the above formula (1)) = 0 to 1.0
　本発明の紫外線硬化型樹脂組成物における単官能（メタ）アクリレート化合物（Ｂ）の含有量は、通常、紫外線硬化型樹脂組成物の総量１００重量部に対して、通常１０～６０重量部であり、好ましくは１５～５０重量部であるが、密着性と柔軟性、復元性を向上させる観点から、前記のエポキシ（メタ）アクリレート（Ａ）が、３０重量部以上で、Ａ／Ｂ＝０．８～１．４５との条件を満たす範囲が好ましく、２０．７重量部以上が好ましい。単官能（メタ）アクリレート化合物（Ｂ）の含有量は、特に好ましくは、２０～４０重量部の範囲内で、且つ、前記のエポキシ（メタ）アクリレート（Ａ）との上記の関係を満たす範囲である。１０重量部未満である場合には、密着性、柔軟性、復元性を奏することができない可能性が有り、６０重量部を超えると、十分な硬度が得られない可能性が有る。 The content of the monofunctional (meth) acrylate compound (B) in the ultraviolet curable resin composition of the present invention is usually 10 to 60 parts by weight with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition. However, from the viewpoint of improving adhesion, flexibility and restorability, the epoxy (meth) acrylate (A) is 30 parts by weight or more, and A / B = 0. A range that satisfies the condition of 8 to 1.45 is preferable, and 20.7 parts by weight or more is preferable. The content of the monofunctional (meth) acrylate compound (B) is particularly preferably in the range of 20 to 40 parts by weight and in the range satisfying the above relationship with the epoxy (meth) acrylate (A). is there. When the amount is less than 10 parts by weight, there is a possibility that adhesion, flexibility, and restorability cannot be achieved, and when it exceeds 60 parts by weight, there is a possibility that sufficient hardness cannot be obtained.
　本発明においては、エポキシ（メタ）アクリレート（Ａ）を使用する。エポキシ（メタ）アクリレート（Ａ）は、硬化性の向上や硬化物の硬度や硬化速度を向上させ、硬化時の硬化性を向上させる機能があり、軟化時の接着性をウレタン（メタ）アクリレートに比べて抑える機能がある。また、エポキシ（メタ）アクリレート（Ａ）としては、グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたものであればいずれも使用できる。エポキシ（メタ）アクリレート（Ａ）を得るための好ましいグリシジルエーテル型エポキシ化合物としては、ビスフェノールＡ或いはそのアルキレンオキサイド付加体のジグリシジルエーテル、ビスフェノールＦ或いはそのアルキレンオキサイド付加体のジグリシジルエーテル、水素添加ビスフェノールＡ或いはそのアルキレンオキサイド付加体のジグリシジルエーテル、水素添加ビスフェノールＦ或いはそのアルキレンオキサイド付加体のジグリシジルエーテル、エチレングリコールジグリシジルエーテル、プロピレングリコールジグリシジルエーテル、ネオペンチルグリコールジグリシジルエーテル、ブタンジオールジグリシジルエーテル、へキサンジオールジグリシジルエーテル、シクロヘキサンジメタノールジグリシジルエーテル、ポリプロピレングリコールジグリシジルエーテル等を挙げることができる。 In the present invention, epoxy (meth) acrylate (A) is used. Epoxy (meth) acrylate (A) has the function of improving curability, improving the hardness and curing speed of the cured product, and improving the curability at the time of curing, and the adhesiveness at the time of softening to urethane (meth) acrylate There is a function to suppress compared. Any epoxy (meth) acrylate (A) may be used as long as it is obtained by reacting a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group. Preferred glycidyl ether type epoxy compounds for obtaining the epoxy (meth) acrylate (A) include diglycidyl ether of bisphenol A or its alkylene oxide adduct, diglycidyl ether of bisphenol F or its alkylene oxide adduct, and hydrogenated bisphenol. A or its alkylene oxide adduct diglycidyl ether, hydrogenated bisphenol F or its alkylene oxide adduct diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, butanediol diglycidyl Ether, hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, It may be mentioned polypropylene glycol diglycidyl ether.
　本発明において好適に使用することができるエポキシ（メタ）アクリレート（Ａ）としては、ビスフェノールＡ型のエポキシ化合物より得られた、ビスフェノールＡ型エポキシアクリレートである。
　ビスフェノールＡ型エポキシアクリレートとして、例えば、ビスフェノールＡのグリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレートを挙げることができる。より具体的には、下記式（２）
Figure JPOXMLDOC01-appb-I000005
（式中、ｎは０～２０の整数を示す。）
で表される液状グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレートを好適に使用でき、上記式（２）の化合物において、好ましいエポキシ当量は１５０ｇ／ｅｑ．～５５０ｇ／ｅｑ．であり、より好ましくは１８０ｇ／ｅｑ．～２００ｇ／ｅｑ．である。エポキシ当量が１５０ｇ／ｅｑ．より低い場合には、紫外線硬化型樹脂組成物を硬化させた時の反りが大きくなりすぎる恐れがあり、５５０ｇ／ｅｑ．を超えると、夏場による温度変化による影響を受けやすくなり、保管が困難となる恐れがあるためである。 The epoxy (meth) acrylate (A) that can be suitably used in the present invention is a bisphenol A type epoxy acrylate obtained from a bisphenol A type epoxy compound.
Examples of the bisphenol A type epoxy acrylate include an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound of bisphenol A with a (meth) acrylate compound having a carboxy group. More specifically, the following formula (2)
Figure JPOXMLDOC01-appb-I000005
(In the formula, n represents an integer of 0 to 20.)
An epoxy (meth) acrylate obtained by reacting a liquid glycidyl ether type epoxy compound represented by the formula (2) with a (meth) acrylate compound having a carboxy group can be suitably used. The equivalent is 150 g / eq. ˜550 g / eq. And more preferably 180 g / eq. ~ 200 g / eq. It is. Epoxy equivalent is 150 g / eq. If it is lower, the warp when the ultraviolet curable resin composition is cured may be too large, and 550 g / eq. This is because it is likely to be affected by the temperature change due to summer and storage may become difficult.
　カルボキシ基を有する（メタ）アクリレート化合物としては、（ａ）不飽和カルボン酸またはその誘導体、及び、（ｂ）ヒドロキシ（メタ）アクリレート化合物のラクトン付加物（ｂ１）と多塩基酸無水物（ｂ２）から得られる化合物、が挙げられる。
　上記（ａ）の不飽和カルボン酸またはその誘導体としては、例えば、（メタ）アクリル酸（アクリル酸又はメタクリル酸）、マレイン酸、α－エチルアクリル酸、フマール酸、イタコン酸、シトラコン酸、テトラヒドロフタル酸、メチルテトラヒドロフタル酸等の不飽和カルボン酸、及びこれらの酸ハライド、アミド、イミド、無水物、エステル等の誘導体を使用することができる。これらの中では、（メタ）アクリル酸が好ましい。
　上記（ｂ）の化合物、即ち、ヒドロキシ（メタ）アクリレート化合物のラクトン付加物（ｂ１）と多塩基酸無水物（ｂ２）から得られる化合物としては、例えば、ヒドロキシ（メタ）アクリレート化合物のラクトン付加物と、多塩基酸無水物のモル比が０．９～１．１、好ましくは等モルで反応させて得られる化合物を挙げることが出来る。
　上記反応は、重合禁止剤の存在下、反応温度５０～１５０℃、好ましくは６０℃～１２０℃で反応させることが望ましい。
　ヒドロキシ（メタ）アクリレート化合物のラクトン付加物（ｂ１）は、ヒドロキシ（メタ）アクリレート化合物にラクトンを開環付加して得ることができる。
　ヒドロキシ（メタ）アクリレート化合物としては、ヒドロキシエチル（メタ）アクリレート、ヒドロキシプロピル（メタ）アクリレート、ヒドロキシブチル（メタ）アクリレート、ジメチロールシクロヘキシルモノ（メタ）アクリレート、ヒドロキシカプロラクトン（メタ）アクリレート等が挙げられる。中でも、ヒドロキシエチル（メタ）アクリレートの使用が好ましい。
　ラクトンとしては、β－プロピオラクトン、β－ブチロラクトン、γ－ブチロラクトン、γ－バレロラクトン、δ－バレロラクトン、β－メチル－γ－バレロラクトン、γ－カプロラクトン、ε－カプロラクトン等を使用することができる。
　１モルのヒドロキシ（メタ）アクリレート化合物に２モルのε－カプロラクトンが付加した化合物が好ましい。
　多塩基無水物（ｂ２）としては、フタル酸無水物、１，２，３，６－テトラヒドロフタル酸無水物及びその誘導体、３，４，５，６－テトラヒドロフタル酸無水物及びその誘導体、１，２，３，４－テトラヒドロフタル酸無水物及びその誘導体、２，３，４，５－テトラヒドロフタル酸無水物及びその誘導体、ヘキサヒドロフタル酸無水物及びその誘導体、琥珀酸無水物及びその誘導体、モノアルキル琥珀酸無水物及びその誘導体、ジアルキル琥珀酸無水物及びその誘導体、マレイン酸無水物及びその誘導体、モノアルキルマレイン酸無水物及びその誘導体、ジアルキルマレイン酸無水物及びその誘導体が挙げられる。中でもフタル酸無水物、テトラヒドロフタル酸無水物、ヘキサヒドロフタル酸無水物を用いることが好ましい。 As the (meth) acrylate compound having a carboxy group, (a) an unsaturated carboxylic acid or a derivative thereof, and (b) a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride (b2) The compound obtained from is mentioned.
Examples of the unsaturated carboxylic acid (a) or derivative thereof include (meth) acrylic acid (acrylic acid or methacrylic acid), maleic acid, α-ethylacrylic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthal Acids, unsaturated carboxylic acids such as methyltetrahydrophthalic acid, and derivatives of these acid halides, amides, imides, anhydrides, esters, and the like can be used. Of these, (meth) acrylic acid is preferred.
Examples of the compound (b), that is, the compound obtained from the lactone adduct (b1) of the hydroxy (meth) acrylate compound and the polybasic acid anhydride (b2) include, for example, a lactone adduct of the hydroxy (meth) acrylate compound. And a compound obtained by reacting the polybasic acid anhydride in a molar ratio of 0.9 to 1.1, preferably equimolar.
The above reaction is desirably carried out in the presence of a polymerization inhibitor at a reaction temperature of 50 to 150 ° C., preferably 60 to 120 ° C.
The lactone adduct (b1) of a hydroxy (meth) acrylate compound can be obtained by ring-opening addition of a lactone to a hydroxy (meth) acrylate compound.
Examples of the hydroxy (meth) acrylate compound include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylol cyclohexyl mono (meth) acrylate, hydroxycaprolactone (meth) acrylate, and the like. Among these, use of hydroxyethyl (meth) acrylate is preferable.
As the lactone, β-propiolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, β-methyl-γ-valerolactone, γ-caprolactone, ε-caprolactone, etc. may be used. it can.
A compound in which 2 mol of ε-caprolactone is added to 1 mol of hydroxy (meth) acrylate compound is preferred.
Examples of the polybasic anhydride (b2) include phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride and derivatives thereof, 3,4,5,6-tetrahydrophthalic anhydride and derivatives thereof, 1 2,3,4-tetrahydrophthalic anhydride and derivatives thereof, 2,3,4,5-tetrahydrophthalic anhydride and derivatives thereof, hexahydrophthalic anhydride and derivatives thereof, succinic anhydride and derivatives thereof Monoalkyl succinic anhydride and derivatives thereof, dialkyl succinic anhydride and derivatives thereof, maleic anhydride and derivatives thereof, monoalkyl maleic anhydride and derivatives thereof, and dialkyl maleic anhydride and derivatives thereof. Of these, phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride are preferably used.
　エポキシ（メタ）アクリレート（Ａ）は、これらグリシジルエーテル型エポキシ化合物と、カルボキシ基を有する（メタ）アクリレート化合物を、下記のような条件で反応させることにより得られる。
　グリシジルエーテル型エポキシ化合物のエポキシ基１当量に対して、カルボキシ基を有する（メタ）アクリレート化合物のカルボキシ基を０．９～１．５当量、より好ましくは０．９５～１．１当量の比率で反応させる。反応温度は８０～１２０℃が好ましく、反応時間は１０～３５時間程度である。反応を促進させるために、例えばトリフェニルフォスフィン、ＴＡＰ（トリアルキルホスフィン）、トリエタノールアミン、テトラエチルアンモニウムクロライド等の触媒を使用するのが好ましい。又、反応中、重合を防止するために重合禁止剤として、例えば、パラメトキシフェノール、メチルハイドロキノン等を使用することもできる。 The epoxy (meth) acrylate (A) is obtained by reacting these glycidyl ether type epoxy compounds with a (meth) acrylate compound having a carboxy group under the following conditions.
The carboxy group of the (meth) acrylate compound having a carboxy group is 0.9 to 1.5 equivalents, more preferably 0.95 to 1.1 equivalents with respect to 1 equivalent of the epoxy group of the glycidyl ether type epoxy compound. React. The reaction temperature is preferably 80 to 120 ° C., and the reaction time is about 10 to 35 hours. In order to promote the reaction, it is preferable to use a catalyst such as triphenylphosphine, TAP (trialkylphosphine), triethanolamine, or tetraethylammonium chloride. Further, in order to prevent polymerization during the reaction, for example, paramethoxyphenol, methylhydroquinone or the like can be used as a polymerization inhibitor.
　本発明の紫外線硬化型樹脂組成物においては、エポキシ（メタ）アクリレート（Ａ）の含量は本発明の紫外線硬化型樹脂組成物の総量１００重量部に対して通常３０重量部以上であり、好ましくは４０重量部以上であり、より好ましくは、５０重量部以上である。上限は特に限定されないが、通常８０重量部以下であり、好ましくは７０重量部以下であり、より好ましくは６０重量部以下である。
３０重量部未満であると、湿度変化または温度変化による反りの変化量が大きくなり、表面硬化性に劣り、さらに高温保管時に接着剤として働いてしまう可能性があるためである。 In the ultraviolet curable resin composition of the present invention, the content of the epoxy (meth) acrylate (A) is usually 30 parts by weight or more with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition of the present invention, preferably The amount is 40 parts by weight or more, and more preferably 50 parts by weight or more. Although an upper limit is not specifically limited, Usually, it is 80 weight part or less, Preferably it is 70 weight part or less, More preferably, it is 60 weight part or less.
This is because if the amount is less than 30 parts by weight, the amount of change in warpage due to humidity change or temperature change is increased, surface curability is inferior, and it may work as an adhesive during high temperature storage.
　本発明の紫外線硬化型樹脂組成物の好ましい態様においては、エポキシ（メタ）アクリレート（Ａ）として、グリシジルエーテル型エポキシ化合物と（メタ）アクリル酸を反応させることにより得られたエポキシ（メタ）アクリレート（Ａ１）を含有する。
　上記の好ましい態様における、上記エポキシ（メタ）アクリレート（Ａ１）と、単官能（メタ）アクリレート（Ｂ）を含む光ディスク用紫外線硬化型樹脂組成物において、紫外線硬化型樹脂組成物の総量１００重量部に対する、上記エポキシ（メタ）アクリレート（Ａ１）の含有割合（紫外線硬化型樹脂組成物の総量１００重量部に対する（Ａ１）成分の重量部）をＡ１重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合（紫外線硬化型樹脂組成物の総量１００重量部に対する（Ｂ）成分の重量部）をＢ重量部とした場合、Ａ１／Ｂが０．８～１．４５の範囲が好ましい。当該割合が０．８未満であれば、高温保管時の安定性が劣り、１．４５を超えると硬化時の反りが大きくなる。ここで、単官能（メタ）アクリレート（Ｂ）として、前記、式（１）で表される化合物またはジシクロペンテニル（メタ）アクリレートを含有し、その含有割合がＢ１重量部の時、Ａ１／Ｂ１の範囲が上記Ａ１／Ｂの範囲と同一の値となるとき、即ち、Ａ１／Ｂ１が０．８～１．４５の範囲であるとき、より好ましい。
　また、上記において、単官能（メタ）アクリレート（Ｂ）として、前記、式（１）で表される化合物またはジシクロペンテニル（メタ）アクリレートを含有し、且つ、Ａ１／Ｂ１が上記の範囲である時、他の単官能（メタ）アクリレート化合物を含まなくてもよいが、必要に応じて、他の単官能（メタ）アクリレート化合物を含有させても構わない。該他の単官能（メタ）アクリレートを含む場合、場合によってはＡ／Ｂが０．８～１．４５の範囲から外れても、本願発明の効果を達成することができる場合があり、そのような場合は本発明の範囲に入る。 In a preferred embodiment of the ultraviolet curable resin composition of the present invention, an epoxy (meth) acrylate obtained by reacting a glycidyl ether type epoxy compound and (meth) acrylic acid as the epoxy (meth) acrylate (A) ( A1) is contained.
In the ultraviolet curable resin composition for optical discs containing the epoxy (meth) acrylate (A1) and the monofunctional (meth) acrylate (B) in the above preferred embodiment, the total amount of the ultraviolet curable resin composition is 100 parts by weight. The content ratio of the epoxy (meth) acrylate (A1) (parts by weight of the component (A1) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition) is A1 parts by weight, and the monofunctional (meth) acrylate compound (B ) Content (parts by weight of component (B) relative to 100 parts by weight of the total amount of the ultraviolet curable resin composition) is B parts by weight, A1 / B is preferably in the range of 0.8 to 1.45. If the said ratio is less than 0.8, stability at the time of high temperature storage will be inferior, and if it exceeds 1.45, the curvature at the time of hardening will become large. Here, as the monofunctional (meth) acrylate (B), when the compound represented by the formula (1) or dicyclopentenyl (meth) acrylate is contained and the content ratio is B1 parts by weight, A1 / B1 Is more preferably the same as the range of A1 / B, that is, when A1 / B1 is in the range of 0.8 to 1.45.
Moreover, in the above, the monofunctional (meth) acrylate (B) contains the compound represented by the formula (1) or dicyclopentenyl (meth) acrylate, and A1 / B1 is in the above range. At this time, other monofunctional (meth) acrylate compounds may not be included, but other monofunctional (meth) acrylate compounds may be included as necessary. When the other monofunctional (meth) acrylate is included, the effect of the present invention may be achieved even if A / B is out of the range of 0.8 to 1.45. In this case, it falls within the scope of the present invention.
　本発明の樹脂組成物においては、エポキシ（メタ）アクリレート（Ａ）と単官能（メタ）アクリレート化合物との両者の含有割合（Ａ／Ｂ）を０．８～１．４５の範囲の含有割合とすることで、エポキシ（メタ）アクリレート（Ａ）の紫外線硬化型樹脂組成物中の紫外線硬化型樹脂組成物の総量１００重量部に対する含有割合が３０重量部以上と高い場合にも、硬化時の反りを有効に低減することが可能となり、復元性、硬化性も付与することができる。
　即ち、多官能であるエポキシ（メタ）アクリレート（Ａ）に上記の割合で単官能（メタ）アクリレート（Ｂ）が結合していくことによって、単官能（メタ）アクリレートでさらなる架橋が抑えられ、架橋が高度に３次元に行われることを防止し、硬化時の反りと高温環境下での保管性の優れたバランスを実現することが可能となる。特に、単官能（メタ）アクリレートとして、上記式（１）の化合物を上記比率でエポキシ（メタ）アクリレートと配合した場合、特に顕著に、エポキシ（メタ）アクリレートの特性を保持させたまま、低収縮性、柔軟性を付与することができる。
　また、上記比率で配合することで、湿度変化、温度変化による反りの変化量、特に、耐久試験後における反りの変化量を、プラス又はマイナス０．６未満で、スペックアウトしない程度に抑えられる硬化物を提供することができる。
　また、本発明の好ましい態様においては、上記の変化量を、何れも、プラス又はマイナス０．５以下、更に好ましくはプラス又はマイナス０．４以下に抑えることができ、記録特性の信頼性をより向上させることができる。
　より優れた硬化時の反りの低減性能、温度変化による反りの変化量又は耐久試験後の反りの変化量の抑制機能を付与する観点からは、上記Ａ／Ｂは０．８～１．４１未満が好ましい。
　また、他の特性なども考慮すると、上記Ａ／Ｂは０．８～１．３がより好ましく、０．８～１．１が更に好ましい。
　なお、硬化時の反りの変化量、及び温度変化の反りの変化量又は耐久試験後の反りの変化量が、樹脂を塗布する前の基板の反りを基準として、プラス又はマイナス０．６以上であると、記録特性が悪く信頼性に懸念が大きくなる。
　本発明の樹脂組成物においては、エポキシ（メタ）アクリレート（Ａ）及び単官能（メタ）アクリレート化合物（Ｂ）の両者の含有量は前記の通りであるが、両者の合計含量が、本発明の樹脂組成物の総量１００重量部あたり、通常８０～９９重量％であり、好ましくは、９０～９９重量部、より好ましくは、９２～９７重量部である。 In the resin composition of the present invention, the content ratio (A / B) of both the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound is 0.8 to 1.45. Thus, even when the content ratio of the epoxy (meth) acrylate (A) to the total amount of 100 parts by weight of the ultraviolet curable resin composition in the ultraviolet curable resin composition is as high as 30 parts by weight or more, the warp at the time of curing. Can be effectively reduced, and restoring properties and curability can also be imparted.
That is, the monofunctional (meth) acrylate (B) is bonded to the polyfunctional epoxy (meth) acrylate (A) at the above ratio, so that further crosslinking is suppressed by the monofunctional (meth) acrylate. Can be prevented from being carried out in a highly three-dimensional manner, and an excellent balance between warpage during curing and storage in a high temperature environment can be realized. In particular, as a monofunctional (meth) acrylate, when the compound of the above formula (1) is blended with the epoxy (meth) acrylate at the above ratio, the shrinkage is particularly low while maintaining the characteristics of the epoxy (meth) acrylate. And flexibility can be imparted.
In addition, by blending at the above ratio, the amount of change in warpage due to changes in humidity and temperature, especially the amount of change in warpage after the endurance test, can be suppressed to a level that does not cause spec-out by less than plus or minus 0.6. Things can be provided.
Further, in a preferred embodiment of the present invention, any of the above-mentioned changes can be suppressed to plus or minus 0.5 or less, more preferably plus or minus 0.4 or less, and the reliability of recording characteristics is further improved. Can be improved.
From the viewpoint of imparting better curving reduction performance during curing, a function of suppressing warpage change due to temperature change, or warpage change after endurance test, A / B is less than 0.8 to less than 1.41 Is preferred.
In consideration of other characteristics, the A / B is more preferably 0.8 to 1.3, and still more preferably 0.8 to 1.1.
The amount of change in warpage during curing, the amount of change in warpage due to temperature change, or the amount of change in warpage after the durability test is plus or minus 0.6 or more, based on the warpage of the substrate before applying the resin. If so, the recording characteristics are poor and the concern about reliability increases.
In the resin composition of the present invention, the contents of both the epoxy (meth) acrylate (A) and the monofunctional (meth) acrylate compound (B) are as described above. The amount is usually 80 to 99% by weight, preferably 90 to 99 parts by weight, more preferably 92 to 97 parts by weight, per 100 parts by weight of the total amount of the resin composition.
　本発明の紫外線硬化型樹脂組成物においては、光重合開始剤（Ｃ）を使用する。本発明に使用できる光重合開始剤（Ｃ）としては、例えば、ベンゾインイソブチルエーテル、２，４－ジエチルチオキサントン、２－イソプロピルチオキサントン、ベンジル、１－ヒドロキシシクロヘキシルフェニルケトン、ベンゾインエチルエーテル、ベンジルジメチルケタール、２－ヒドロキシ－２－メチル－１－フェニルプロパン－１－オン、１－（４－イソプロピルフェニル）－２－ヒドロキシ－２－メチルプロパン－１－オン及び２－メチル－１－（４－メチルチオフェニル）－２－モルフォリノプロパン－１－オン等の分子開裂型や、ベンゾフェノン、４－フェニルベンゾフェノン、イソフタルフェノン、４－ベンゾイル－４’－メチル－ジフェニルスルフィド等の水素引き抜き型の光重合開始剤等がある。これらは、１種または２種以上を併用して用いてもよく、特に内部硬化性を向上させる観点から２，４，６－トリメチルベンゾイルジフェニルフォスフィンオキサイドを併用にて用いることが好ましい。
　光重合開始剤（Ｃ）の紫外線硬化型樹脂組成物中の含有量は、紫外線硬化型樹脂組成物の総量１００重量部に対して通常１～１０重量部であり、好ましくは３～８重量部である。 In the ultraviolet curable resin composition of the present invention, a photopolymerization initiator (C) is used. Examples of the photopolymerization initiator (C) that can be used in the present invention include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, benzyl, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- (4-methylthiophenyl) ) Molecular cleavage type such as 2-morpholinopropan-1-one, hydrogen abstraction type photopolymerization initiator such as benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenyl sulfide, etc. There is. These may be used alone or in combination of two or more, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide is preferably used in combination from the viewpoint of improving internal curability.
The content of the photopolymerization initiator (C) in the ultraviolet curable resin composition is usually 1 to 10 parts by weight, preferably 3 to 8 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. It is.
　本発明の紫外線硬化型樹脂組成物においては、必要によりウレタン（メタ）アクリレートを含有させることができる。ウレタン（メタ）アクリレートは好適の量使用することで、光ディスクの機械的特性（反り、ゆがみ等）を向上させる機能がある。 In the ultraviolet curable resin composition of the present invention, urethane (meth) acrylate can be contained if necessary. By using a suitable amount of urethane (meth) acrylate, there is a function of improving the mechanical properties (warping, distortion, etc.) of the optical disk.
　好適に併用することができるウレタン（メタ）アクリレートは、多価アルコール、ポリイソシアネート及びヒドロキシ（メタ）アクリレート化合物を反応させることによって得ることができる。 Urethane (meth) acrylate that can be suitably used in combination can be obtained by reacting polyhydric alcohol, polyisocyanate and hydroxy (meth) acrylate compound.
　使用することができる多価アルコールとしては、例えば、下記の多価アルコールを挙げることができる。
（ｉ）ポリエチレングリコール、ポリプロピレングリコール、ポリテトラメチレングリコール等のポリアルキレングリコール、
（ｉｉ）ネオペンチルグリコール、３－メチル－１，５－ペンタンジオール、プロピレングリコール、１，４－ブタンジオール、１，６－ヘキサンジオール、トリメチロールプロパン、ペンタエリスリトール、トリシクロデカンジメチロール、ビス－〔ヒドロキシメチル〕－シクロヘキサン等の脂肪族アルコール、
（ｉｉｉ）上記（ｉ）記載の脂肪族多価アルコールの一種と多塩基酸との反応によって得られるポリエステルポリオール。
　なお上記の多塩基酸としては、例えば、コハク酸、フタル酸、ヘキサヒドロ無水フタル酸、テレフタル酸、アジピン酸、アゼライン酸、テトラヒドロ無水フタル酸等を挙げることができる。 Examples of the polyhydric alcohol that can be used include the following polyhydric alcohols.
(I) polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol,
(Ii) Neopentyl glycol, 3-methyl-1,5-pentanediol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, tricyclodecane dimethylol, bis- Aliphatic alcohols such as [hydroxymethyl] -cyclohexane,
(Iii) A polyester polyol obtained by reacting one of the aliphatic polyhydric alcohols described in (i) above with a polybasic acid.
Examples of the polybasic acid include succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, and tetrahydrophthalic anhydride.
（ｉｖ）多価アルコールとε－カプロラクトンとの反応によって得られるカプロラクトンアルコール。
（ｖ）ポリカーボネートポリオール。例えば１，６－ヘキサンジオールとジフェニルカーボネートとの反応によって得られるポリカーボネートジオール等。
（ｖｉ）ポリエーテルポリオール。例えばポリエチレングリコール又はポリプロピレングリコール等のポリＣ２－Ｃ３アルキレングリコール、エチレンオキサイド変性ビスフェノールＡ等。
　これらの数平均分子量は２００～８０００程度が好ましく、より好ましくは２００～３０００程度である。 (Iv) Caprolactone alcohol obtained by reaction of polyhydric alcohol and ε-caprolactone.
(V) Polycarbonate polyol. For example, polycarbonate diol obtained by reaction of 1,6-hexanediol and diphenyl carbonate.
(Vi) Polyether polyol. For example, poly C2-C3 alkylene glycol such as polyethylene glycol or polypropylene glycol, ethylene oxide modified bisphenol A and the like.
These number average molecular weights are preferably about 200 to 8000, more preferably about 200 to 3000.
　ポリイソシアネートとしては、例えばイソホロンジイソシアネート、ヘキサメチレンジイソシアネート、トリレンジイソシアネート、キシレンジイソシアネート、ジフェニルメタン－４，４’－ジイソシアネート又はジシクロペンタニルイソシアネート等が挙げられる。
　この場合において、イソホロンジイソシアネート又はトリレンジイソシアネートの使用が好ましい。 Examples of the polyisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4′-diisocyanate, and dicyclopentanyl isocyanate.
In this case, the use of isophorone diisocyanate or tolylene diisocyanate is preferred.
　使用することができるヒドロキシ（メタ）アクリレート化合物としては、ヒドロキシエチル（メタ）アクリレート、ヒドロキシプロピル（メタ）アクリレート、ヒドロキシブチル（メタ）アクリレート、ジメチロールシクロヘキシルモノ（メタ）アクリレート、ヒドロキシカプロラクトン（メタ）アクリレート等が挙げられる。中でも、ヒドロキシエチル（メタ）アクリレートの使用が好ましい。 The hydroxy (meth) acrylate compounds that can be used include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylol cyclohexyl mono (meth) acrylate, and hydroxycaprolactone (meth) acrylate. Etc. Among these, use of hydroxyethyl (meth) acrylate is preferable.
　前記反応は、例えば、以下のようにして行う。即ち、多価アルコールにその水酸基１当量あたり有機ポリイソシアネートをそのイソシアネート基が好ましくは１．１～２．０当量になるように混合し、反応温度を好ましくは７０～９０℃で反応させ、ウレタンオリゴマーを合成する。次いで、ウレタンオリゴマーのイソシアネート基１当量あたり、ヒドロキシ（メタ）アクリレート化合物をその水酸基が好ましくは１～１．５当量となるように混合し、７０～９０℃で反応させて目的とするウレタン（メタ）アクリレートを得ることができる。ウレタン（メタ）アクリレートの分子量としては４００～１００００程度が好ましい。ウレタン（メタ）アクリレートの重量平均分子量としては７０００～２５０００程度が好ましく、１００００～２００００がより好ましい。重量平均分子量が７０００より小さいと収縮が大きくなり、重量平均分子量が２５０００より大きいと硬化性が乏しくなる。 The reaction is performed, for example, as follows. That is, the polyhydric alcohol is mixed with an organic polyisocyanate per equivalent of the hydroxyl group so that the isocyanate group is preferably 1.1 to 2.0 equivalent, and reacted at a reaction temperature of preferably 70 to 90 ° C. Synthesize oligomers. Next, the hydroxy (meth) acrylate compound is mixed so that the hydroxyl group is preferably 1 to 1.5 equivalents per equivalent of the isocyanate group of the urethane oligomer, and reacted at 70 to 90 ° C. to react with the target urethane (meth). ) Acrylate can be obtained. The molecular weight of urethane (meth) acrylate is preferably about 400 to 10,000. The weight average molecular weight of the urethane (meth) acrylate is preferably about 7,000 to 25,000, and more preferably 10,000 to 20,000. When the weight average molecular weight is less than 7000, shrinkage increases, and when the weight average molecular weight is greater than 25000, curability is poor.
　本発明の紫外線硬化型樹脂組成物におけるウレタン（メタ）アクリレートの含有量は、湿度変化、温度変化による反りの変化量の抑制機能、硬度を付与しながら、密着性と柔軟性、復元性を向上させる観点から、紫外線硬化型樹脂組成物の総量１００重量部に対して０～２０重量部であり、好ましくは０～１０重量部である。２０重量部を超えると、十分な硬度が得られず、湿度変化、温度変化による反りの変化量の抑制機能に劣るといった問題が生じるため、本発明の目的とする効果を奏することができなくなるため好ましくない。
　高温環境下（３０℃～４０℃）での保管の安定性を高める観点から、ウレタン（メタ）アクリレートの含有割合が２０重量部以下であることが好ましい。 The content of urethane (meth) acrylate in the ultraviolet curable resin composition of the present invention improves adhesion, flexibility, and resilience while imparting a function to suppress the change in warpage due to changes in humidity and temperature, and hardness. In view of the above, it is 0 to 20 parts by weight, preferably 0 to 10 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. If the amount exceeds 20 parts by weight, sufficient hardness cannot be obtained, and problems such as inferior function of suppressing change in warpage due to humidity change and temperature change occur, and the intended effect of the present invention cannot be achieved. It is not preferable.
From the viewpoint of enhancing storage stability in a high temperature environment (30 ° C. to 40 ° C.), the content of urethane (meth) acrylate is preferably 20 parts by weight or less.
　本発明の樹脂組成物においては、必要に応じて、多官能（メタ）アクリレート化合物（以下（Ｂ）以外の（メタ）アクリレートモノマーともいう）を含有することも出来る。なお、本発明においては、該多官能（メタ）アクリレート化合物又は（Ｂ）以外の（メタ）アクリレートモノマーの語は、前記のウレタン（メタ）アクリレート及びエポキシ（メタ）アクリレートを除いた多官能（メタ）アクリレート化合物（（Ｂ）以外の（メタ）アクリレートモノマー）を意味する。
　（Ｂ）以外の（メタ）アクリレートモノマーとしては、（メタ）アクリロイル基を複数有するものであれば良いが、通常２～６個有する多官能（メタ）アクリレート化合物（以下（メタ）アクリロイル基を２～６個有する（メタ）アクリレートモノマーともいう）であり、ジ（メタ）アクリレートモノマーが好ましい。
　（メタ）アクリロイル基を２個有する（メタ）アクリレートモノマーとしては、シクロヘキサン－１，４－ジメタノールジ（メタ）アクリレート、シクロヘキサン－１，３－ジメタノールジ（メタ）アクリレート、トリシクロデカンジメチロールジ（メタ）アクリレート（例えば、日本化薬株式会社製、ＫＡＹＡＲＡＤ　Ｒ－６８４、トリシクロデカンジメチロールジアクリレート等）、ジシクロペンタニルジ（メタ）アクリレート等のＣ５～Ｃ１０脂肪族環を有するジ（メタ）アクリレート化合物、ジオキサングリコールジ（メタ）アクリレート（例えば、日本化薬株式会社製、ＫＡＹＡＲＡＤ　Ｒ－６０４、ジオキサングリコールジアクリレート等）等のヘテロ環を有するジ（メタ）アクリレート化合物、エチレンオキサイド変性１，６－ヘキサンジオールジ（メタ）アクリレート等のＣ２～Ｃ１０アルキルジ（メタ）アクリレート及びそのアルキレンオキサイド変性物、ネオペンチルグリコールジ（メタ）アクリレート、アルキレンオキサイド変性ネオペンチルグリコールジ（メタ）アクリレート等の分岐鎖を有するＣ２～Ｃ１０アルキレンジ（メタ）アクリレート及びそのアルキレンオキサイド変性物、ヒドロキシピバリン酸ネオペンチルグリコールジ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート等のポリアルキレングリコールグリコールジ（メタ）アクリレート、アルキレンオキサイド変性ビスフェノールＡ型ジ（メタ）アクリレート及びエチレンオキサイド変性リン酸ジ（メタ）アクリレート等を挙げることができる。
　この場合において、Ｃ２～Ｃ１０アルキレンジ（メタ）アクリレートまたはそのアルキレンオキサイド変性物を使用することが、温度変化による反りの変化量を抑える観点、耐久性の観点及び、硬度を向上させる観点から好ましい。 The resin composition of the present invention may contain a polyfunctional (meth) acrylate compound (hereinafter also referred to as (meth) acrylate monomer other than (B)) as necessary. In the present invention, the term “polyfunctional (meth) acrylate compound” or “(meth) acrylate monomer other than (B)” refers to a polyfunctional (meta) excluding the urethane (meth) acrylate and epoxy (meth) acrylate. ) Means an acrylate compound (a (meth) acrylate monomer other than (B)).
As the (meth) acrylate monomer other than (B), any monomer having a plurality of (meth) acryloyl groups may be used, but usually 2 to 6 polyfunctional (meth) acrylate compounds (hereinafter referred to as 2 (meth) acryloyl groups). (Also referred to as 6 to (meth) acrylate monomers), and di (meth) acrylate monomers are preferred.
Examples of the (meth) acrylate monomer having two (meth) acryloyl groups include cyclohexane-1,4-dimethanol di (meth) acrylate, cyclohexane-1,3-dimethanol di (meth) acrylate, and tricyclodecane dimethylol di (meth). Di (meth) acrylates having C5-C10 aliphatic rings such as acrylates (for example, KAYARAD R-684, tricyclodecane dimethylol diacrylate, etc., manufactured by Nippon Kayaku Co., Ltd.), dicyclopentanyl di (meth) acrylate, etc. Compounds, di (meth) acrylate compounds having a heterocycle such as dioxane glycol di (meth) acrylate (for example, KAYARAD R-604, dioxane glycol diacrylate, etc., manufactured by Nippon Kayaku Co., Ltd.), ethylene oxide modified 1,6- It has a branched chain such as C2-C10 alkyl di (meth) acrylate such as xanthdiol di (meth) acrylate and its alkylene oxide modified product, neopentyl glycol di (meth) acrylate, alkylene oxide modified neopentyl glycol di (meth) acrylate, etc. C2-C10 alkylene di (meth) acrylate and its modified alkylene oxide, polypylene glycol diglycol dihydroxypivalate neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, etc. (Meth) acrylate, alkylene oxide modified bisphenol A type di (meth) acrylate and ethylene oxide modified di (meth) acrylate And the like.
In this case, it is preferable to use C2 to C10 alkylene di (meth) acrylate or a modified alkylene oxide thereof from the viewpoint of suppressing the amount of warpage due to a temperature change, from the viewpoint of durability, and from the viewpoint of improving hardness.
　（Ｂ）以外の（メタ）アクリレートモノマーについて（メタ）アクリロイル基を３個有する（メタ）アクリレートモノマーとしては、トリメチロールプロパントリ（メタ）アクリレート、トリメチロールオクタントリ（メタ）アクリレート等のトリメチロールＣ２～Ｃ１０アルカントリ（メタ）アクリレート、トリメチロールプロパンポリエトキシトリ（メタ）アクリレート、トリメチロールプロパンポリプロポキシトリ（メタ）アクリレート、トリメチロールプロパンポリエトキシポリプロポキシトリ（メタ）アクリレート等のトリメチロールＣ２～Ｃ１０アルカンポリアルコキシトリ（メタ）アクリレート、トリス［（メタ）アクロイルオキシエチル］イソシアヌレ－ト、ペンタエリスリトールトリ（メタ）アクリレート、エチレンオキサイド変性トリメチロールプロパントリ（メタ）アクリレート、プロピレンオキサイド変性トリメチロールプロパントリ（メタ）アクリレート等のアルキレンオキサイド変性トリメチロールプロパントリ（メタ）アクリレート等を挙げることができる。 (Meth) acrylate monomer other than (B) The (meth) acrylate monomer having three (meth) acryloyl groups includes trimethylol C2 such as trimethylolpropane tri (meth) acrylate and trimethyloloctanetri (meth) acrylate. Trimethylol C2 to C10 such as C10 alkane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, trimethylolpropane polyethoxypolypropoxytri (meth) acrylate Alkane polyalkoxy tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, pentaerythritol tri (meth) acrylate, ethylene Side-modified trimethylolpropane tri (meth) acrylate, alkylene oxide modified trimethylolpropane tri (meth) acrylate such as propylene oxide-modified trimethylolpropane tri (meth) acrylate.
　（Ｂ）以外の（メタ）アクリレートモノマーについて（メタ）アクリロイル基を４個有する（メタ）アクリレートモノマーとしては、ペンタエリスリトールポリエトキシテトラ（メタ）アクリレート、ペンタエリスリトールポリプロポキシテトラ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジトリメチロールプロパンテトラ（メタ）アクリレート、ジペンタエリスリトールテトラ（メタ）アクリレート等を挙げることができる。 (Meth) acrylate monomers other than (B) (meth) acrylate monomers having four (meth) acryloyl groups include pentaerythritol polyethoxytetra (meth) acrylate, pentaerythritol polypropoxytetra (meth) acrylate, and pentaerythritol. Examples include tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and dipentaerythritol tetra (meth) acrylate.
　（Ｂ）以外の（メタ）アクリレートモノマーについて（メタ）アクリロイル基を５個有する（メタ）アクリレートモノマーとしては、ジペンタエリスリトールペンタ（メタ）アクリレート等を挙げることができる。 (Meth) acrylate monomer other than (B) Examples of the (meth) acrylate monomer having five (meth) acryloyl groups include dipentaerythritol penta (meth) acrylate.
　（Ｂ）以外の（メタ）アクリレートモノマーについて（メタ）アクリロイル基を６個有する（メタ）アクリレートモノマーとしては、ジペンタエリスリトールヘキサ（メタ）アクリレート等を挙げることができる。
　なお、本発明において用いうる（メタ）アクリレートモノマーは、（メタ）アクリロイル基を７個以上有する多官能のものであってもよい。 Regarding (meth) acrylate monomers other than (B), examples of the (meth) acrylate monomer having 6 (meth) acryloyl groups include dipentaerythritol hexa (meth) acrylate.
The (meth) acrylate monomer that can be used in the present invention may be a polyfunctional monomer having 7 or more (meth) acryloyl groups.
　本発明の紫外線硬化型樹脂組成物においては、これら（メタ）アクリレートモノマー成分は、１種または２種以上を任意の割合で混合して使用することができる。これら（メタ）アクリレートモノマー成分の紫外線硬化型樹脂組成物中の含有量は紫外線硬化型樹脂組成物の総量１００重量部に対して通常０～１０重量部程度、場合によっては、１０～８０重量部、好ましくは２０～７０重量部である。 In the ultraviolet curable resin composition of the present invention, these (meth) acrylate monomer components can be used alone or in admixture of two or more at any ratio. The content of these (meth) acrylate monomer components in the ultraviolet curable resin composition is usually about 0 to 10 parts by weight, and in some cases, 10 to 80 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. The amount is preferably 20 to 70 parts by weight.
　本発明の紫外線硬化型樹脂組成物に使用できる添加剤としては、増感剤、シランカップリング剤、界面活性剤、レベリング剤、熱重合禁止剤、ヒンダードフェノール、ホスファイト等の酸化防止剤、ヒンダードアミン等の光安定剤を使用することもできる。これらは本発明の樹脂組成物中には含まなくても良いが、必要に応じて用いることも出来る。
　増感剤としては、例えば、トリメチルアミン、メチルジメタノールアミン、トリエタノールアミン、ｐ－ジメチルアミノアセトフェノン、ｐ－ジメチルアミノ安息香酸エチル、ｐ－ジメチルアミノ安息香酸イソアミル、Ｎ，Ｎ－ジメチルベンジルアミン及び４，４’－ビス（ジエチルアミノ）ベンゾフェノン等が使用でき、更に、前記の光重合性化合物と付加反応を起こさないアミン類を併用することもできる。好ましくはディスク作製時のハンドリング性の観点からヒンダードピペリジン骨格を有する化合物を使用することが有用である。 Additives that can be used in the ultraviolet curable resin composition of the present invention include sensitizers, silane coupling agents, surfactants, leveling agents, thermal polymerization inhibitors, antioxidants such as hindered phenols and phosphites, Light stabilizers such as hindered amines can also be used. These may not be included in the resin composition of the present invention, but can be used as necessary.
Examples of the sensitizer include trimethylamine, methyldimethanolamine, triethanolamine, p-dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine and 4 4,4′-bis (diethylamino) benzophenone and the like can be used, and the photopolymerizable compound can be used in combination with an amine that does not cause an addition reaction. Preferably, it is useful to use a compound having a hindered piperidine skeleton from the viewpoint of handleability during disk production.
　使用できるヒンダートアミン化合物としてのヒンダートピペリジン骨格を有する化合物は公知のものであれば、特に限定することなく使用することができるが、具体的には、例えば、２，２，６，６－テトラメチル－４－ピペリジノン、２，２，６，６－テトラメチル－４－ピペリジノ－ル、１，２，２，６，６－ペンタメチル－４－ピペリジノ－ル、４－ヒドロキシ－２，２，６，６－テトラメチル－１－ピペリジンエタノ－ル、１，２，２，６，６－ペンタメチル－４－ピペリジルメタクリレ－ト、２，２，６，６－テトラメチル－４－ピペリジルメタクリレ－ト、ビス（１，２，２，６，６－ペンタメチル－４－ピペリジル）セバケイト、ビス（２，２，６，６－テトラメチル－４－ピペリジル）セバケイト、ポリ{[６－(１，１，３，３－テトラメチルブチル)アミノ－１，３，５－トリアジン－２，４－ジイル][(２，２，６，６－テトラメチル－4－ピペリジル)イミノ]ヘキサメチレン[(２，２，６，６－テトラメチル－４－ピペリジル)イミノ]}、コハク酸ジメチルと１－(２－ヒドロキシエチル)－４－ヒドロキシ－２，２，６，６－テトラメチルピペリジンの重縮合物、２－(３，５－ジ－t－ヒドロキシベンジル)－２－n－ブチルマロン酸ビス(１，２，２，６，６－ペンタメチル－４－ピペリジル)、テトラキス(２，２，６，６－テトラメチル－４－ピペリジル)１，２，３，４－ブタンテトラカルボキシレ－ト、１，２，３，４－ブタンテトラカルボン酸と１，２，２，６，６－ペンタメチル－４－ピペリジノ－ル及び１－トリデカノ－ルの混合エステル化物、１，２，３，４－ブタンテトラカルボン酸と２，２，６，６－テトラメチル－４－ピペリジノ－ル及び１－トリデカノ－ルとの混合エステル化物、１，２，３，４－ブタンテトラカルボン酸と１，２，２，６，６－ペンタメチル－４－ピペリジノ－ル及び３，９－ビス（２－ヒドロキシ－１，１－ジメチルエチル）－２，４，８，１０－テトラオキサスピロ[５．５]ウンデカンとの混合エステル化物、１，２，３，４－ブタンテトラカルボン酸と２，２，６，６－テトラメチル－４－ピペリジノ－ル及び３，９－ビス（２－ヒドロキシ－１，１－ジメチルエチル）－２，４，８，１０－テトラオキサスピロ[５．５]ウンデカンとの混合エステル化物からなる群から選択される少なくとも１種のヒンダ－ドアミン化合物を使用することができる。中でも、優れた耐久性を付与する観点から、１，２，２，６，６－ペンタメチル－４－ピペリジルアルコール、２，２，６，６－テトラメチル－４－ピペリジルアルコール、１，２，２，６，６－ペンタメチル－４－ピペリジル（メタ）アクリレート（アデカ（株）製、ＬＡ－８２）を好適に使用することができる。
　ヒンダートピペリジン骨格を有する化合物において、ヒンダートとはピペリジン骨格を有する化合物に置換基として結合している、分岐鎖を有する炭化水素基を示し、好ましく使用されるのは、上記置換基がｔ－ブチル基を有するものである。また、硬化物とした時に、ヒンダートピペリジン骨格を有する化合物自体が架橋されることから、不純物として析出されることが少なく、紫外線硬化型樹脂組成物の硬化性を損ねることもないため、（メタ）アクリロイル基を有するヒンダートピペリジン骨格を有する化合物を特に好適に使用することができる。
　ヒンダートピペリジン骨格を有する化合物の紫外線硬化型樹脂組成物中の含有量は、紫外線硬化型樹脂組成物の総量１００重量部に対して通常０．０１～１０重量部であり、好ましくは０．０３～８重量部であり、特に好ましくは０．０３～５重量部である。 As the hindered amine compound that can be used, any compound having a hindered piperidine skeleton can be used without particular limitation as long as it is a known one. Specifically, for example, 2,2,6,6- Tetramethyl-4-piperidinone, 2,2,6,6-tetramethyl-4-piperidinol, 1,2,2,6,6-pentamethyl-4-piperidinol, 4-hydroxy-2,2, 6,6-tetramethyl-1-piperidine ethanol, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly {[6- (1, 1,3, -Tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6 6-tetramethyl-4-piperidyl) imino]}, polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, 2- (3 , 5-di-t-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), tetrakis (2,2,6,6-tetramethyl- 4-piperidyl) 1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 1-tridecanol mixed ester, 1,2,3,4 Mixed esterified product of butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and 1-tridecanol, 1,2,3,4-butanetetracarboxylic acid and 1,2, 2,6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethyl) Ethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane and at least one hindered amine compound selected from the group consisting of esterified products can be used. Among them, from the viewpoint of imparting excellent durability, 1,2,2,6,6-pentamethyl-4-piperidyl alcohol, 2,2,6,6-tetramethyl-4-piperidyl alcohol, 1,2,2 , 6,6-pentamethyl-4-piperidyl (meth) acrylate (manufactured by Adeka Co., Ltd., LA-82) can be preferably used.
In a compound having a hindered piperidine skeleton, hinder refers to a hydrocarbon group having a branched chain bonded as a substituent to a compound having a piperidine skeleton. The substituent is preferably t-butyl. It has a group. Further, when the cured product is used, the compound itself having a hindered piperidine skeleton is cross-linked, so that it is hardly precipitated as an impurity and does not impair the curability of the ultraviolet curable resin composition. ) A compound having a hindered piperidine skeleton having an acryloyl group can be particularly preferably used.
The content of the compound having a hindered piperidine skeleton in the ultraviolet curable resin composition is usually 0.01 to 10 parts by weight, preferably 0.03 parts per 100 parts by weight of the total amount of the ultraviolet curable resin composition. -8 parts by weight, particularly preferably 0.03-5 parts by weight.
　またシランカップリング剤としては公知のシランカップリング剤であれば特に限定することなく使用することができる。 Any known silane coupling agent can be used without any particular limitation as the silane coupling agent.
　また、優れた耐久性を付与することができる酸化防止剤を添加することができる。
具体的には、ビス［２－メチル－４－［３－（ドデシルチオ）プロピオニルオキシ］－５－ｔｅｒｔ－ブチルフェニル］スルフィド及びビス［２－メチル－４－［３－（テトラデシルチオ）プロピオニルオキシ］－５－ｔｅｒｔ－ブチルフェニル］スルフィド、ビス{2-メチル-4-[3-N-アルキル（C12又はC14）チオプロビオニルオキシ]－５－ｔｅｒｔ－ブチルフェニル}スルフィド等が挙げられ、市場からＡＯ－２３（例えば、株式会社ＡＤＥＫＡ製）として入手することが可能である。 Further, an antioxidant capable of imparting excellent durability can be added.
Specifically, bis [2-methyl-4- [3- (dodecylthio) propionyloxy] -5-tert-butylphenyl] sulfide and bis [2-methyl-4- [3- (tetradecylthio) propionyloxy ] -5-tert-butylphenyl] sulfide, bis {2-methyl-4- [3-N-alkyl (C12 or C14) thiopropionyloxy] -5-tert-butylphenyl} sulfide, etc. Can be obtained as AO-23 (for example, manufactured by ADEKA Corporation).
　酸化防止剤の紫外線硬化型樹脂組成物中の含有量は、紫外線硬化型樹脂組成物の総量１００重量部に対して通常０．０１～１０重量部であり、好ましくは０．０３～８重量部であり、特に好ましくは０．０３～５重量部である。
　本発明の樹脂組成物の好ましい態様を以下に示す。
（Ｉ）エポキシ（メタ）アクリレート（Ａ）が式（２）で表されるグリシジルエーテル型エポキシ化合物と（メタ）アクリル酸との反応で得られたエポキシ（メタ）アクリレートであり、
単官能（メタ）アクリレート化合物（Ｂ）を含み、
　本発明の樹脂組成物の総量１００重量部に対する、前記エポキシ（メタ）アクリレート（Ａ）の含有割合が３０～６０重量部であり、その含有割合をＡ重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合をＢ重量部とした時、Ａ／Ｂが０．８～１．４５であり、
光重合開始剤（Ｃ）の含量が、本発明の樹脂組成物の総量１００重量部に対し、１～１０重量部であるブルーレイディスク用紫外線硬化型樹脂組成物。
（ＩＩ）単官能（メタ）アクリレート化合物（Ｂ）として、式（１）で表される化合物を含み、その含量が、単官能（メタ）アクリレート化合物（Ｂ）の総量１００重量部に対して、４０～１００重量部であり、残部が、それ以外の単官能（メタ）アクリレート化合物である上記（Ｉ）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（ＩＩＩ）単官能（メタ）アクリレート化合物（Ｂ）として、ジシクロペンテニルオキシエチル（メタ）アクリレートを、単官能（メタ）アクリレート化合物（Ｂ）の総量１００重量部に対して、１００重量部以下の範囲で含み、残部が、それ以外の単官能（メタ）アクリレート化合物である上記（Ｉ）又は（ＩＩ）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（ＩＶ）単官能（メタ）アクリレート化合物（Ｂ）が、式（１）で表される化合物単独、又は、式（１）で表される化合物とジシクロペンテニルオキシエチル（メタ）アクリレートの両者である上記（Ｉ）又は（ＩＩ）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。
（Ｖ）ジシクロペンテニルオキシエチル（メタ）アクリレートの含量が、式（１）で表される化合物１００重量部に対して、１００重量部以下である上記（ＩＶ）に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The content of the antioxidant in the ultraviolet curable resin composition is usually 0.01 to 10 parts by weight, preferably 0.03 to 8 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. Particularly preferred is 0.03 to 5 parts by weight.
The preferable aspect of the resin composition of this invention is shown below.
(I) The epoxy (meth) acrylate (A) is an epoxy (meth) acrylate obtained by a reaction between a glycidyl ether type epoxy compound represented by the formula (2) and (meth) acrylic acid,
Including a monofunctional (meth) acrylate compound (B),
The content ratio of the epoxy (meth) acrylate (A) is 30 to 60 parts by weight with respect to 100 parts by weight of the total amount of the resin composition of the present invention, the content ratio is A part by weight, and the monofunctional (meth) acrylate When the content ratio of the compound (B) is B parts by weight, A / B is 0.8 to 1.45,
An ultraviolet curable resin composition for Blu-ray Disc, wherein the content of the photopolymerization initiator (C) is 1 to 10 parts by weight with respect to 100 parts by weight of the total amount of the resin composition of the present invention.
(II) As a monofunctional (meth) acrylate compound (B), the compound represented by the formula (1) is included, and the content thereof is 100 parts by weight with respect to the total amount of the monofunctional (meth) acrylate compound (B). The ultraviolet curable resin composition for Blu-ray Discs as described in (I) above, which is 40 to 100 parts by weight and the balance is the other monofunctional (meth) acrylate compound.
(III) As monofunctional (meth) acrylate compound (B), dicyclopentenyloxyethyl (meth) acrylate is 100 parts by weight or less with respect to 100 parts by weight of the total amount of monofunctional (meth) acrylate compound (B). The ultraviolet curable resin composition for Blu-ray Discs as described in (I) or (II) above, wherein the remainder is a monofunctional (meth) acrylate compound other than that.
(IV) The monofunctional (meth) acrylate compound (B) is a compound represented by the formula (1) alone, or both a compound represented by the formula (1) and dicyclopentenyloxyethyl (meth) acrylate. The ultraviolet curable resin composition for Blu-ray Discs according to (I) or (II) above.
(V) The ultraviolet curing for Blu-ray Disc according to (IV) above, wherein the content of dicyclopentenyloxyethyl (meth) acrylate is 100 parts by weight or less with respect to 100 parts by weight of the compound represented by formula (1) Mold resin composition.
　本発明の光ディスク用紫外線硬化型樹脂組成物は、前記した各成分を常温～８０℃で混合溶解して得ることができ、必要により夾雑物をろ過等の操作により取り除いてもよい。本発明の樹脂組成物は、塗布性を考え、本発明の紫外線硬化型樹脂組成物の粘度は、２５℃において、３００～２０００（ｍＰａ・ｓ）であることが好ましく、５００～１２００（ｍＰａ・ｓ）であることがより好ましい。粘度を当該範囲とすることで厚膜形成が容易になり、タクトタイムを短縮することができる。
　また、本発明の紫外線硬化型樹脂組成物としては、溶媒を用いない方が好ましく、用いたとしても、紫外線硬化型樹脂組成物の総量１００重量部に対して１０重量部未満であることが好ましく、５重量部未満であることが特に好ましい。 The ultraviolet curable resin composition for an optical disk of the present invention can be obtained by mixing and dissolving the above-mentioned components at room temperature to 80 ° C. If necessary, impurities may be removed by an operation such as filtration. The resin composition of the present invention has a coating property, and the viscosity of the ultraviolet curable resin composition of the present invention is preferably 300 to 2000 (mPa · s) at 25 ° C., and preferably 500 to 1200 (mPa · s). More preferably, s). By setting the viscosity within the range, thick film formation can be facilitated, and the tact time can be shortened.
Moreover, as the ultraviolet curable resin composition of the present invention, it is preferable not to use a solvent, and even if it is used, it is preferably less than 10 parts by weight with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition. Particularly preferred is less than 5 parts by weight.
　本発明の紫外線硬化型樹脂組成物においては、紫外線照射後に形成される硬化物の２５℃における弾性率が１０００～３０００ＭＰａであるが、１５００～２５００ＭＰａであることがより好ましく、１８００～２２００ＭＰａであることが特に好ましい。１０００ＭＰａ未満であると十分な硬度を有することができず、３０００ＭＰａを超えると硬化時の反りが大きくなりすぎる恐れがあるためである。また、５０℃における弾性率は、通常３５～１５００ＭＰａであり、４５～１５００ＭＰａが好ましい。
　さらに、温度変化での反りが少ない方が、温度変化により生じる信号特性のエラーを有効に防ぐことができることから、２５℃と比較した時の５℃～５５℃のそりの変化量が０．８度未満であることが好ましく、０．６度未満であることが特に好ましい。
　また、本発明の樹脂組成物を、光ディスクに適用して硬化物層を形成するとき、特に、ブルーレイディスクの光透過層を形成する時、硬化時の反り（初期反り）の変化量が小さい方が好ましく、その変化量が塗布前の基板反りとの差で、０．６度未満が好ましい。該変化量が０．６度以上になると、急激に読み取りエラーが増加する傾向にある。好ましくは、０．５７度以下であり、より好ましくは０．５度以下であり、更に好ましくは、０．４度以下である。
　また、上記と同様な理由により、本発明の樹脂組成物の硬化物層を光透過層として有する光ディスク、好ましくはブルーレイディスクにおける、耐久試験後の反りの変化量も、０．６度未満が好ましく、より好ましくは、０．５度以下であり、更に好ましくは、０．４度以下である。
　また、紫外線照射後に形成される硬化層におけるガラス転移温度（Ｔｇ）は好ましくは４０℃以上である。４０℃未満であると、高温環境下（３０～４０℃）において、弾性率が急激に低下し、柔軟性が極端に上昇するため、接着剤として機能する、即ち、接着性が生じる、恐れがあるためである。 In the ultraviolet curable resin composition of the present invention, the cured product formed after ultraviolet irradiation has an elastic modulus at 25 ° C. of 1000 to 3000 MPa, more preferably 1500 to 2500 MPa, and more preferably 1800 to 2200 MPa. Is particularly preferred. This is because if it is less than 1000 MPa, sufficient hardness cannot be obtained, and if it exceeds 3000 MPa, warpage during curing may be too large. Further, the elastic modulus at 50 ° C. is usually 35 to 1500 MPa, preferably 45 to 1500 MPa.
Furthermore, since the signal characteristic error caused by the temperature change can be effectively prevented when the warp due to the temperature change is small, the amount of change in the warp from 5 ° C. to 55 ° C. compared to 25 ° C. is 0.8. The angle is preferably less than 0.6 degrees, and particularly preferably less than 0.6 degrees.
In addition, when the cured product layer is formed by applying the resin composition of the present invention to an optical disc, particularly when forming a light-transmitting layer of a Blu-ray disc, the amount of change in warpage (initial warpage) upon curing is small. It is preferable that the amount of change is a difference from the warpage of the substrate before coating, and less than 0.6 degrees. When the amount of change is 0.6 degrees or more, reading errors tend to increase rapidly. Preferably, it is 0.57 degree or less, More preferably, it is 0.5 degree or less, More preferably, it is 0.4 degree or less.
For the same reason as described above, the amount of change in warpage after an endurance test in an optical disc, preferably a Blu-ray disc, having a cured product layer of the resin composition of the present invention as a light transmission layer is preferably less than 0.6 degrees. More preferably, it is 0.5 degrees or less, and still more preferably 0.4 degrees or less.
Moreover, the glass transition temperature (Tg) in the hardened layer formed after ultraviolet irradiation is preferably 40 ° C. or higher. When the temperature is lower than 40 ° C., the elastic modulus rapidly decreases and the flexibility increases extremely in a high temperature environment (30 to 40 ° C.), so that it functions as an adhesive, that is, adhesion may occur. Because there is.
［光ディスク］
　本発明の光ディスクは、基板上に、少なくとも光反射層と光透過層とが形成され、前記光透過層を通してレーザー光により記録又は再生を行う光ディスクであって、前記光透過層が、本発明の光透過層用紫外線硬化型樹脂組成物の硬化物からなるものである。本発明の光ディスクは、光透過層として、本発明の光ディスク用紫外線硬化型樹脂組成物を使用することにより、湿度変化、温度変化により反りの変化量が少ない硬化物を得ることができるため、良好に情報の記録・再生を行うことができる。 [optical disk]
The optical disc of the present invention is an optical disc in which at least a light reflection layer and a light transmission layer are formed on a substrate, and recording or reproduction is performed with a laser beam through the light transmission layer. It consists of hardened | cured material of the ultraviolet curable resin composition for light transmissive layers. The optical disk of the present invention is excellent in that a cured product having a small amount of change in warpage due to humidity change and temperature change can be obtained by using the ultraviolet curable resin composition for optical disk of the present invention as a light transmission layer. In addition, information can be recorded / reproduced.
　本発明の光ディスクにおける光透過層は、レーザー光の発振波長が３７０～４３０ｎｍであるブルーレーザーを効率良く透過することが好ましく、１００μｍの厚さにおいて４０５ｎｍの光の透過率が８５％以上であることが好ましく、９０％以上であることが特に好ましい。 The light transmission layer in the optical disk of the present invention preferably transmits a blue laser having a laser light oscillation wavelength of 370 to 430 nm efficiently, and has a light transmittance of 405 nm at a thickness of 100 μm of 85% or more. Is preferable, and 90% or more is particularly preferable.
　光透過層の厚みは総厚さが５０～１５０μｍの範囲であり、７５～１５０μｍであることが特に好ましい。光透過層の厚みは、単層の場合、約１００μｍに設定されるが、厚みは光透過率や信号の読み取り及び記録に大きく影響を及ぼすため、十分な管理が必要である。光透過層は、当該厚さの硬化層単層で形成されていても、複数層が積層されていてもよい。複数層の場合には各光透過層の厚さの和が上記厚さの範囲であることが好ましい。 The total thickness of the light transmission layer is in the range of 50 to 150 μm, and 75 to 150 μm is particularly preferable. In the case of a single layer, the thickness of the light transmission layer is set to about 100 μm. However, since the thickness greatly affects the light transmittance and signal reading and recording, sufficient management is required. The light transmission layer may be formed of a single cured layer having the thickness or a plurality of layers may be laminated. In the case of a plurality of layers, it is preferable that the sum of the thicknesses of the respective light transmission layers is in the above-mentioned thickness range.
　光反射層としては、レーザー光を反射し、記録・再生が可能な光ディスクを形成できるものであればよく、例えば、金、銀、銅、アルミニウムなどの金属又はその合金、シリコンなどの無機化合物を使用できる。なかでも、４００ｎｍ近傍の光の反射率が高いことから銀又は銀を主成分とする合金を使用することが好ましい。光反射層の厚さは、１０～６０ｎｍ程度の厚さとすることが好ましい。
　通常、光反射層は基板に前記金属又はその合金を蒸着させることにより形成される。 The light reflecting layer may be any layer that can reflect a laser beam and form an optical disk that can be recorded and reproduced. For example, a metal such as gold, silver, copper, or aluminum or an alloy thereof, or an inorganic compound such as silicon. Can be used. Of these, silver or an alloy containing silver as a main component is preferably used because of the high reflectance of light in the vicinity of 400 nm. The thickness of the light reflecting layer is preferably about 10 to 60 nm.
Usually, the light reflecting layer is formed by vapor-depositing the metal or an alloy thereof on a substrate.
　基板としては、ディスク形状の円形樹脂基板を使用でき、当該樹脂としてはポリカーボネートを好ましく使用できる。光ディスクが再生専用の場合には、基板上に情報記録を担うピットが光反射層と積層される表面に形成される。 As the substrate, a disk-shaped circular resin substrate can be used, and polycarbonate can be preferably used as the resin. When the optical disc is read-only, pits for recording information are formed on the surface of the substrate that is laminated with the light reflecting layer.
　また、書込可能な光ディスクの場合には、光反射層と光透過層との間に記録層が設けられる。記録層としては、情報の記録・再生が可能であればよく、相変化型記録層、光磁気記録層、あるいは有機色素型記録層のいずれであってもよい。
　書込可能な光ディスクは、基板の記録情報面に記録層が設けられている。記録層は、光記録媒体用の記録層として従来公知の材料を適宜利用可能である。例えば、色素、アモルファス半導体、部分窒化膜、部分酸化膜（無機膜）などが挙げられる。
　光記録媒体は上記記録層を複数有していてもよいが、この場合、各々の層が同じ材料で形成されていてもよいし、別の材料を任意に組み合わせて形成してもよい。このようにすることで各層毎に透過率などの光学的性質を変えることができる。
　記録層の具体的な種類としては、無機型記録層と有機色素型記録層が挙げられる。 In the case of a writable optical disc, a recording layer is provided between the light reflecting layer and the light transmitting layer. The recording layer only needs to be capable of recording / reproducing information, and may be any of a phase change recording layer, a magneto-optical recording layer, and an organic dye recording layer.
A writable optical disc has a recording layer on the recording information surface of the substrate. As the recording layer, a conventionally known material can be appropriately used as a recording layer for an optical recording medium. Examples thereof include a dye, an amorphous semiconductor, a partial nitride film, and a partial oxide film (inorganic film).
The optical recording medium may include a plurality of the recording layers. In this case, each layer may be formed of the same material, or may be formed by arbitrarily combining different materials. By doing so, optical properties such as transmittance can be changed for each layer.
Specific examples of the recording layer include an inorganic type recording layer and an organic dye type recording layer.
　記録層に使用される無機型記録層であるアモルファス半導体材料の具体例としては、ＳｂＴｅ系、ＧｅＴｅ系、ＧｅＳｂＴｅ系、ＩｎＳｂＴｅ系、ＡｇＳｂＴｅ系、ＡｇＩｎＳｂＴｅ系、ＧｅＳｂ系、ＧｅＳｂＳｎ系、ＩｎＧｅＳｂＴｅ系、ＩｎＧｅＳｂＳｎＴｅ系等の材料が挙げられる。これらの中でも、結晶化速度を高めるために、Ｓｂを主成分とする組成物を用いることが好ましい。なお、これらのアモルファス半導体材料は、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 Specific examples of the amorphous semiconductor material which is an inorganic type recording layer used for the recording layer include SbTe, GeTe, GeSbTe, InSbTe, AgSbTe, AgInSbTe, GeSb, GeSbSn, InGeSbTe, InGeSbSnTe And the like. Among these, in order to increase the crystallization speed, it is preferable to use a composition containing Sb as a main component. In addition, these amorphous semiconductor materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
　記録層に使用される無機型記録層である部分窒化膜、部分酸化膜の具体例としては、ＢｉＧｅＮ、ＳｎＮｂＮなどの部分窒化膜、ＴｅＯx、ＢｉＦＯxなどの部分酸化膜が挙げられる。 Specific examples of the partial nitride film and partial oxide film that are inorganic type recording layers used for the recording layer include partial nitride films such as BiGeN and SnNbN, and partial oxide films such as TeOx and BiFOx.
　また、記録層として、有機色素型記録層を用いることができる。有機色素型記録層の材料は、記録再生に使用するレーザー光の波長に感光性がある必要がある。さらに、有機色素型記録層の材料はレーザー光の照射により物理変化あるいは化学反応することにより屈折率が変化する必要がある。そのため、有機色素型記録層の材料としては、例えば、シアニン色素、オキソノール色素、アゾ色素、フタロシアニン色素、ポリフィリン系色素が挙げられる。これらの有機材料を例えば、セロソルブアセテート、テトラフルオロプロパノール等の溶剤と混合した溶液を用い、スピンコート法などにより有機色素型記録層を形成する。有機色素型記録層の膜厚は１５ｎｍ以上、２５ｎｍ以下が好ましい。 Also, an organic dye type recording layer can be used as the recording layer. The material of the organic dye-type recording layer needs to be sensitive to the wavelength of the laser beam used for recording and reproduction. Furthermore, the refractive index of the material of the organic dye-type recording layer needs to be changed by a physical change or chemical reaction caused by laser light irradiation. Therefore, examples of the material for the organic dye type recording layer include cyanine dyes, oxonol dyes, azo dyes, phthalocyanine dyes, and porphyrin dyes. An organic dye type recording layer is formed by spin coating or the like using a solution obtained by mixing these organic materials with a solvent such as cellosolve acetate or tetrafluoropropanol. The film thickness of the organic dye type recording layer is preferably 15 nm or more and 25 nm or less.
　ここで、記録層上に界面層を有していても構わない。界面層は、記録層に発生する熱を緩衝する機能、ディスクの反射率を調整する機能を求められ、光透過層の成膜時における有機色素型記録層に含まれる色素の光透過層への拡散や、光透過層の形成用の硬化樹脂の溶剤等の有機色素層への浸透などの混和現象を防止する機能がある。この界面層を構成する材料は、通常二酸化ケイ素と硫化亜鉛の混合組成が用いられ、他には酸化ケイ素特に二酸化ケイ素や酸化亜鉛、酸化セリウム、酸化イットリウム、酸化インジウム、酸化インジウムスズ、酸化ガリウム等の酸化物、硫化亜鉛、硫化イットリウムなどの硫化物、窒化ケイ素などの窒化物、炭化ケイ素、酸化物とイオウとの混合物、酸化アルミニウム、マグネシウム、カルシウム等のフッ化物等が挙げられる。この界面層はスパッタリング等の方法で形成される。
　本発明の紫外線硬化型樹脂組成物は界面層、具体的には、二酸化ケイ素と硫化亜鉛の混合組成や酸化インジウム、酸化インジウムスズに対する密着性に優れることから好適に使用できる。 Here, an interface layer may be provided on the recording layer. The interface layer is required to have a function of buffering heat generated in the recording layer and a function of adjusting the reflectivity of the disc, and the dye contained in the organic dye type recording layer at the time of film formation of the light transmitting layer is applied to the light transmitting layer. It has a function of preventing mixing phenomena such as diffusion and penetration of a cured resin for forming a light transmission layer into an organic dye layer such as a solvent. As the material constituting the interface layer, a mixed composition of silicon dioxide and zinc sulfide is usually used. In addition, silicon oxide, particularly silicon dioxide, zinc oxide, cerium oxide, yttrium oxide, indium oxide, indium tin oxide, gallium oxide, etc. Oxides, sulfides such as zinc sulfide and yttrium sulfide, nitrides such as silicon nitride, silicon carbide, mixtures of oxide and sulfur, fluorides such as aluminum oxide, magnesium and calcium. This interface layer is formed by a method such as sputtering.
The ultraviolet curable resin composition of the present invention can be suitably used because of its excellent adhesion to an interface layer, specifically, a mixed composition of silicon dioxide and zinc sulfide and indium oxide and indium tin oxide.
　本願発明の光ディスクは、記録層（情報記録部位）が二つ以上形成されていても良い。例えば、再生専用光ディスクの場合には、ピットを有する基板上に、第一の光反射層、第一の光透過層が積層され、当該第一の光透過層上又は他の層を積層し、当該層上に第二の光反射層、第二の光透過層を形成してもよい。この場合には第一の光透過層やこれに積層する他の層上にピットが形成される。また、記録・再生可能な光ディスクの場合は、基板上に、記録層、光反射層及び光透過層が積層された構成を有するものであるが、当該光透過層上に更に、第二の光反射層、第二の記録層、第二の光透過層を形成して二層の記録層を有する構成、あるいは、同様に層を積層して三層以上の記録層を有する構成としてもよい。複数層を積層する場合には、各層の層厚さの和が上記の厚さになるように適宜調整すればよい。
　本発明の紫外線硬化型樹脂組成物を光透過層に用いた場合には、光透過層が接する界面層或いは記録層の腐食や劣化を抑えることができ、好適に記録層を有する光ディスクにも使用することができる。 In the optical disk of the present invention, two or more recording layers (information recording sites) may be formed. For example, in the case of a read-only optical disc, a first light reflection layer and a first light transmission layer are laminated on a substrate having pits, and the first light transmission layer or other layers are laminated, A second light reflection layer and a second light transmission layer may be formed on the layer. In this case, pits are formed on the first light transmission layer and other layers laminated thereon. In addition, in the case of a recordable / reproducible optical disc, a recording layer, a light reflecting layer, and a light transmitting layer are laminated on a substrate, and the second light is further formed on the light transmitting layer. The reflective layer, the second recording layer, and the second light transmission layer may be formed to have two recording layers, or the layers may be similarly stacked to have three or more recording layers. In the case of laminating a plurality of layers, it may be appropriately adjusted so that the sum of the layer thicknesses of the respective layers becomes the above-mentioned thickness.
When the ultraviolet curable resin composition of the present invention is used for a light transmissive layer, corrosion or deterioration of an interface layer or a recording layer in contact with the light transmissive layer can be suppressed, and it can be suitably used for an optical disk having a recording layer. can do.
　また、本発明の光ディスクにおいては、光透過層が最表面の層であってもよいが、更にその表層に表面コート層を設けてもよい。 In the optical disc of the present invention, the light transmission layer may be the outermost layer, but a surface coat layer may be further provided on the surface layer.
　本発明の光ディスクには、再生専用のディスクと、記録・再生可能なディスクがある。再生専用のディスクは、１枚の円形樹脂基板を射出成形する際に、情報記録層であるピットを設け、次いで該情報記録層上に光反射層を形成し、更に、（必要により他の層を積層した後）光透過層用紫外線硬化型樹脂組成物を例えば、２Ｐ法、ロールコート法、スクリーン印刷、スピンコート法等により塗布した後、片側もしくは両面から活性エネルギー線として紫外線～近紫外（波長２００～４００ｎｍ付近）を照射することにより硬化させて光透過層を形成することにより製造することができる。また、記録・再生可能なディスクは、１枚の円形樹脂基板上に光反射層を形成し、記録層を設け、更に、該光反射層上に光透過層用紫外線硬化型樹脂組成物をスピンコート法等により塗布した後、紫外線照射により硬化させて光透過層を形成することにより製造することができる。 The optical disc of the present invention includes a read-only disc and a recordable / reproducible disc. When a single circular resin substrate is injection-molded, a read-only disk is provided with pits which are information recording layers, and then a light reflecting layer is formed on the information recording layer. After the UV curable resin composition for the light transmitting layer is applied by, for example, 2P method, roll coating method, screen printing, spin coating method, etc., ultraviolet to near ultraviolet (as an active energy ray from one side or both sides) It can be produced by forming a light transmission layer by curing by irradiation with a wavelength of 200 to 400 nm. In addition, a recordable / reproducible disc is formed by forming a light reflecting layer on a single circular resin substrate, providing a recording layer, and further spinning an ultraviolet curable resin composition for a light transmitting layer on the light reflecting layer. After applying by a coating method or the like, it can be produced by curing by ultraviolet irradiation to form a light transmission layer.
　塗布した光透過層用紫外線硬化型樹脂組成物を紫外線照射することにより硬化させる場合、紫外線～近紫外（波長２００～４００ｎｍ付近）を照射することができるランプであれば特に限定されないが、例えば（パルス）キセノンランプ、無電極ランプ、メタルハライドランプ、低圧、高圧水銀灯若しくは超高圧水銀灯などを用いた連続光照射方式で行うこともできるし、閃光照射方式で行うこともできる。 When the applied UV curable resin composition for a light transmitting layer is cured by irradiating with ultraviolet rays, the lamp is not particularly limited as long as it is capable of irradiating ultraviolet rays to near ultraviolet rays (wavelength of 200 to 400 nm). (Pulse) A xenon lamp, an electrodeless lamp, a metal halide lamp, a low pressure, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, or the like can be used.
　紫外線を照射する場合、積算光量は０．０５～１Ｊ／ｃｍ２となるようにコントロールするのが好ましい。積算光量は０．０５～０．８Ｊ／ｃｍ２であることがより好ましく、０．０５～０．６Ｊ／ｃｍ２であることが特に好ましい。本発明の光ディスクに使用する光透過層用紫外線硬化型樹脂組成物は、硬化性に優れるため、積算光量が少量であっても、十分に硬化し、光ディスク端面や表面のタックが発生せず、更に光ディスクの反りや歪みが発生しない。 When irradiating with ultraviolet rays, it is preferable to control the accumulated light amount to be 0.05 to 1 J / cm 2 . More preferably accumulated light amount is 0.05 ~ 0.8J / cm 2, particularly preferably 0.05 ~ 0.6J / cm 2. The UV curable resin composition for light transmissive layer used in the optical disc of the present invention is excellent in curability, so that it is sufficiently cured even with a small amount of integrated light, and does not cause tack on the end face or surface of the optical disc. Furthermore, there is no warping or distortion of the optical disk.
光ディスクの具体的構成の説明
　以下、本発明の光ディスクの具体例として、単層型光ディスク及び多層型光ディスク（例えば、二層型光ディスク）の具体的構成の一例を以下に示す。 Description of Specific Configuration of Optical Disc Hereinafter, as a specific example of the optical disc of the present invention, an example of a specific configuration of a single layer type optical disc and a multilayer type optical disc (for example, a double layer type optical disc) is shown below.
　本発明の光ディスクのうち、単層型光ディスクの好ましい実施態様としては、例えば、基板上に、光反射層と、光透過層とが積層され、光透過層側からブルーレーザーを入射して情報の記録又は再生を行う構成や、更に光透過層上にハードコート層を設けた構成がある。光透過層は、本発明の紫外線硬化型樹脂組成物の硬化物からなる層であり、その厚さは１００±１０μｍの範囲である。ハードコート層は、高硬度で、耐摩耗性に優れる層であることが好ましい。ハードコート層の厚さは、１～１０μｍであることが好ましく、３～５μｍであることがより好ましい。基板の厚さは１．１ｍｍ程度、光反射層は銀等の薄膜である。
　また、記録層を有する単層型光ディスクの好ましい実施態様としては、例えば、基板上に、光反射層、第１界面層、記録層（無機型記録層、有機色素型記録層いずれでも可）、第２界面層、光透過層が当該順で積層され、光透過層側からブルーレーザーを入射して情報の記録又は再生を行う構成や、更に光透過層上にハードコート層を設けた構成がある。 Among the optical discs of the present invention, as a preferred embodiment of a single-layer type optical disc, for example, a light reflection layer and a light transmission layer are laminated on a substrate, and a blue laser is incident from the light transmission layer side to transmit information. There are configurations in which recording or reproduction is performed and a configuration in which a hard coat layer is further provided on the light transmission layer. The light transmission layer is a layer made of a cured product of the ultraviolet curable resin composition of the present invention, and the thickness thereof is in the range of 100 ± 10 μm. The hard coat layer is preferably a layer having high hardness and excellent wear resistance. The thickness of the hard coat layer is preferably 1 to 10 μm, and more preferably 3 to 5 μm. The thickness of the substrate is about 1.1 mm, and the light reflecting layer is a thin film such as silver.
Further, as a preferred embodiment of the single-layer type optical disc having a recording layer, for example, a light reflection layer, a first interface layer, a recording layer (either an inorganic type recording layer or an organic dye type recording layer is acceptable) on a substrate, A structure in which a second interface layer and a light transmission layer are laminated in this order, and a blue laser is incident from the light transmission layer side to record or reproduce information, and a structure in which a hard coat layer is further provided on the light transmission layer is there.
　多層型光ディスクの好ましい実施態様としては、例えば、基板上に、第１光反射層と、第１光透過層とが積層され、さらにその上に、第２光反射層と、第２光透過層とが積層され、第２光透過層側からブルーレーザーを入射して情報の記録又は再生を行う二層型光ディスクの構成がある。第１光透過層及び第２光透過層は、紫外線硬化型樹脂組成物の硬化物からなる層であり、少なくともいずれかの層が本発明の紫外線硬化型樹脂組成物からなる層である。層の厚さとしては、第１光透過層の厚さと第２光透過層の厚さの和が１００±１０μｍの範囲である。基板の厚さは１．１ｍｍ程度、光反射層は銀等の薄膜である。
　また、記録層を有する多層型光ディスクの好ましい実施態様としては、例えば、基板上に、第１光反射層、第１界面層、第１記録層（無機型記録層、有機色素型記録層いずれでも可）、第２界面層、第１光透過層が当該順で積層され、さらにその上に、第２光反射層、第３界面層、第２記録層（無機、有機色素いずれでも可）、第４界面層、第２光透過層とが積層され、第２光透過層側からブルーレーザーを入射して情報の記録又は再生を行う二層型光ディスクの構成がある。 As a preferred embodiment of the multilayer optical disk, for example, a first light reflection layer and a first light transmission layer are laminated on a substrate, and further, a second light reflection layer and a second light transmission layer are further formed thereon. And a two-layer type optical disc that records or reproduces information by injecting a blue laser from the second light transmission layer side. The first light transmission layer and the second light transmission layer are layers made of a cured product of the ultraviolet curable resin composition, and at least one of the layers is a layer made of the ultraviolet curable resin composition of the present invention. As the thickness of the layer, the sum of the thickness of the first light transmission layer and the thickness of the second light transmission layer is in a range of 100 ± 10 μm. The thickness of the substrate is about 1.1 mm, and the light reflecting layer is a thin film such as silver.
Further, as a preferred embodiment of a multilayer optical disc having a recording layer, for example, a first light reflecting layer, a first interface layer, a first recording layer (inorganic type recording layer, organic dye type recording layer) may be formed on a substrate. Yes), a second interface layer, and a first light transmission layer are laminated in this order, and further, a second light reflection layer, a third interface layer, a second recording layer (any of inorganic and organic dyes are possible), There is a configuration of a two-layer type optical disc in which a fourth interface layer and a second light transmission layer are laminated and a blue laser is incident from the second light transmission layer side to record or reproduce information.
　当該構成の二層型光ディスクにおいては、記録トラック（グルーブ）が、第２光透過層の表面にも形成されるため、光透過層は、接着性に優れる紫外線硬化型樹脂組成物の硬化膜からなる層の上に、記録トラックを好適に形成できる紫外線硬化型樹脂組成物の硬化膜からなる層を積層した複層で形成されていてもよい。また当該構成においても最表層にハードコート層が設けられていてもよい。 In the two-layer type optical disc having the above structure, since the recording track (groove) is also formed on the surface of the second light transmission layer, the light transmission layer is made of a cured film of an ultraviolet curable resin composition having excellent adhesiveness. On the layer to be formed, a multilayer formed by laminating a layer made of a cured film of an ultraviolet curable resin composition capable of suitably forming a recording track may be formed. Also in this configuration, a hard coat layer may be provided on the outermost layer.
　次に、例として光ディスクの製造方法を以下に説明する。
　まず、ポリカーボネート樹脂を射出成形することによって、記録トラック（グルーブ）と呼ばれるレーザー光をトラッキングするための案内溝を有する基板を作製する。次に基板の記録トラック側の表面に、銀合金などをスパッタまたは蒸着することにより光反射層を成膜する。この上に本発明の紫外線硬化型樹脂組成物を塗布し、ディスクの片面または両面から紫外線を照射して、紫外線硬化型樹脂組成物を硬化させ、光透過層を形成、または更にこの上にスピンコート等によりハードコート層を形成する。 Next, an optical disk manufacturing method will be described below as an example.
First, a polycarbonate resin having a guide groove for tracking laser light called a recording track (groove) is manufactured by injection molding a polycarbonate resin. Next, a light reflection layer is formed on the surface of the substrate on the recording track side by sputtering or vapor-depositing a silver alloy or the like. The ultraviolet curable resin composition of the present invention is applied on this, and the ultraviolet curable resin composition is cured by irradiating ultraviolet rays from one or both sides of the disk to form a light transmission layer or spin on this. A hard coat layer is formed by coating or the like.
　以下、本発明を実施例により更に具体的に説明するが、本発明はこれら実施例により何ら制限されるものではない。 Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
　実施例１～９、比較例１～４として下記表１に示した組成からなる紫外線硬化型樹脂組成物を調整した。 Examples 1 to 9 and Comparative Examples 1 to 4 were prepared as ultraviolet curable resin compositions having the compositions shown in Table 1 below.
　得られた本発明の紫外線硬化型樹脂組成物を用いて無機記録層を有するブルーレイディスクを作製し、特性評価を行った。 Using the obtained ultraviolet curable resin composition of the present invention, a Blu-ray disc having an inorganic recording layer was prepared and evaluated for characteristics.
（ブルーレイディスクの作製）
１．トラックピッチ０．３２μｍの案内溝を有する直径１２ｃｍ、厚み１．１ｍｍのポリカーボネート基板に銀合金を１００ｎｍの膜厚になるようスパッタし、反射層を形成した。その後、ＴｉＳｉＯをスパッタし無機記録層を形成した。さらに、ＺｎＳ－ＳｉＯ２（モル比８０：２０）を約１５ｎｍの厚みになるようスパッタし、界面層を形成し、ブルーレイディスク基板を作製した。
２．ブルーレイディスク基板を反射層が上になるようスピンテーブルに乗せ、内径１１．５ｍｍまで覆う様に円状のキャップ処理を行い、ついで本発明または比較用の紫外線硬化型樹脂組成物を３．０ｇ中心部のキャップ上に供給した。
３．９００ｒｐｍの速度範囲で４秒から７秒間スピンコートし、塗布膜厚が９５μｍとなるよう塗布した。スピンコート終了間際にキセノンフラッシュランプを２ショット照射し、表面の流動性が無くなる程度に硬化させた。
４．高圧水銀ランプを使用し、上側から４００ｍＪ／ｃｍ2で３秒間照射して本発明の紫外線硬化型樹脂組成物を完全硬化させた。
５．硬化された本発明の紫外線硬化型樹脂組成物が上になるようスピンテーブルに乗せ、内径１１．５ｍｍまで覆う様に円状のキャップ処理を行い、ついでハードコート層用の紫外線硬化型樹脂組成物（ＨＯＤ３９５０Ｂ、日本化薬株式会社製）を３．０ｇ中心部のキャップ上に供給した。
６．６０００ｒｐｍの速度範囲で４秒から７秒間スピンコートして塗布した。スピンコート終了間際にキセノンフラッシュランプを２ショット照射し、表面の流動性が無くなる程度に硬化させ、本発明のブルーレイディスクを作製した。 (Production of Blu-ray Disc)
1. A reflective layer was formed by sputtering a silver alloy to a thickness of 100 nm on a polycarbonate substrate having a diameter of 12 cm and a thickness of 1.1 mm having guide grooves with a track pitch of 0.32 μm. Thereafter, TiSiO was sputtered to form an inorganic recording layer. Further, ZnS—SiO 2 (molar ratio 80:20) was sputtered to a thickness of about 15 nm to form an interface layer, and a Blu-ray Disc substrate was produced.
2. Place the Blu-ray Disc substrate on the spin table so that the reflective layer is on top, apply a circular cap treatment to cover the inner diameter of 11.5 mm, and then add 3.0 g of the present invention or the comparative UV curable resin composition On top of the cap.
3. Spin coating was performed for 4 seconds to 7 seconds at a speed range of 900 rpm, and the coating film thickness was 95 μm. Immediately after the end of spin coating, the xenon flash lamp was irradiated with two shots, and cured so that the fluidity of the surface disappeared.
4). Using a high pressure mercury lamp, the ultraviolet curable resin composition of the present invention was completely cured by irradiation from the upper side at 400 mJ / cm 2 for 3 seconds.
5. The cured UV curable resin composition of the present invention is placed on a spin table so that a circular cap treatment is performed so as to cover the inner diameter of 11.5 mm, and then the UV curable resin composition for the hard coat layer is applied. (HOD3950B, manufactured by Nippon Kayaku Co., Ltd.) was supplied onto the cap at the center of 3.0 g.
The coating was performed by spin coating at a speed range of 6.6000 rpm for 4 to 7 seconds. A xenon flash lamp was irradiated for 2 shots just before the end of spin coating and cured to such an extent that the surface fluidity disappeared, and the Blu-ray Disc of the present invention was produced.
　得られたブルーレイディスクを用いて物性評価を行ったところ下記表１の結果が得られた。 The physical properties were evaluated using the obtained Blu-ray Disc, and the results shown in Table 1 below were obtained.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　なお、表１中に略称で示した各成分は下記の通りである。
ＥＰ－１：上記式（２）で表されるエポキシ当量が１８７ｇ／ｅｑ．であるグリシジルエーテル型エポキシ化合物のエポキシ基１モルに対して、アクリル酸を１モル反応させることにより得られたエポキシアクリレート
ＥＰ－２：上記式（２）で表されるエポキシ当量が１９３ｇ／ｅｑ．であるグリシジルエーテル型エポキシ化合物のエポキシ基１モルに対して、アクリル酸を１モル反応させることにより得られたエポキシアクリレート
ＵＡ－１：ポリプロピレングリコール（数平均分子量８５０）、イソホロンジイソシアネート及び２－ヒドロキシルエチルアクリレートについて、モル比を１：１．９：１．９で反応させて得たウレタンアクリレート
ＵＡ－２：ポリテトラメチレングリコール（数平均分子量６５０）、イソホロンジイソシアネート及び２－ヒドロキシルエチルアクリレートについて、モル比を１：１．８：１．８で反応させて得たウレタンアクリレート
Ｐｈｏｔｏｍｅｒ４２２６：ジプロピレングリコールジアクリレート、コグニス株式会社製
ＦＡ－３２１Ａ：エチレンオキサイド１０モル変性ビスフェノールＡ型ジアクリレート、日本化成工業株式会社製
Ｍ－２００：１，６－ヘキサンジオールジアクリレート、美源株式会社製
ＴＨＥ－３３０：トリメチロールプロパンポリエトキシトリアクリレート、日本化薬株式会社製
Ｐｈｏｔｏｍｅｒ４０３５：フェノキシエチルアクリレート、コグニス株式会社製
ＦＡ－５１２ＡＳ：ジシクロペンテニルオキシエチルアクリレート、日本化成工業株式会社製
Ｍ－１４２：エチレンオキサイド２モル変性フェノキシエチルアクリレート、エターナル株式会社製
ＬＡ－８２：１，２，２，６，６－ペンタメチル－４－ピペリジルメタアクリレート、旭電化工業株式会社（現：株式会社ＡＤＥＫＡ）製
スピードキュアＴＰＯ：２，４，６－トリメチルベンゾイルジフェニルフォスフィンオキサイド、ＤＫＳＨジャパン株式会社製
イルガキュア１８４：１－ヒドロキシシクロヘキシルフェニルケトン、ＢＡＳＦ株式会社製 In addition, each component shown with the abbreviation in Table 1 is as follows.
EP-1: The epoxy equivalent represented by the above formula (2) is 187 g / eq. Epoxy acrylate EP-2 obtained by reacting 1 mol of acrylic acid with 1 mol of the epoxy group of the glycidyl ether type epoxy compound: The epoxy equivalent represented by the above formula (2) is 193 g / eq. Epoxy acrylate UA-1 obtained by reacting 1 mol of acrylic acid with 1 mol of epoxy group of the glycidyl ether type epoxy compound: Polypropylene glycol (number average molecular weight 850), isophorone diisocyanate and 2-hydroxylethyl For acrylate, molar ratio of urethane acrylate UA-2: polytetramethylene glycol (number average molecular weight 650), isophorone diisocyanate and 2-hydroxylethyl acrylate obtained by reacting at a molar ratio of 1: 1.9: 1.9. 1: 1.8: 1.8 urethane acrylate Photomer 4226: dipropylene glycol diacrylate, FA-321A manufactured by Cognis Co., Ltd .: ethylene oxide 10 mol modified bisphenol Type A diacrylate, Nippon Kasei Kogyo Co., Ltd. M-200: 1,6-hexanediol diacrylate, Bigen Co., Ltd. THE-330: Trimethylolpropane polyethoxytriacrylate, Nippon Kayaku Co., Ltd. Photomer 4035: Phenoxy Ethyl acrylate, Cognis Co., Ltd. FA-512AS: Dicyclopentenyloxyethyl acrylate, Nippon Kasei Kogyo Co., Ltd. M-142: Ethylene oxide 2 mol modified phenoxyethyl acrylate, Eternal Co., Ltd. LA-82: 1, 2, 2 , 6,6-Pentamethyl-4-piperidyl methacrylate, Asahi Denka Kogyo Co., Ltd. (currently ADEKA Corporation) Speed Cure TPO: 2,4,6-Trimethylbenzoyldiphenylphosphine oxide, DKSH Di Baker Ltd. Irgacure 184: 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF Corporation
（弾性率試験）
　ガラス転移温度（Ｔｇ）、５０℃での弾性率は、実施例、比較例の組成により得られた紫外線硬化型樹脂組成物において、紫外線を３秒間照射（１００ｍＪ／ｃｍ２）して硬化することにより、縦４ｍｍ、横１ｍｍ、高さ２ｍｍの直方体状のピースを作製し、動的粘弾性測定装置（セイコーインスツル株式会社製）ＤＭＳ６１００を用い両持ち曲げ試験法にて－５０℃～１５０℃までの温度依存性データを、周波数１０Ｈｚ、昇温速度４℃／分で設定して測定した。 (Elastic modulus test)
The glass transition temperature (Tg) and the elastic modulus at 50 ° C. are determined by irradiating with ultraviolet rays for 3 seconds (100 mJ / cm 2 ) in the ultraviolet curable resin compositions obtained by the compositions of Examples and Comparative Examples. A rectangular parallelepiped piece having a length of 4 mm, a width of 1 mm, and a height of 2 mm was prepared by using a dynamic viscoelasticity measuring device (manufactured by Seiko Instruments Inc.) DMS6100 in a double-end bending test method. The temperature dependence data up to were measured with a frequency set at 10 Hz and a heating rate of 4 ° C./min.
（硬度試験）
　硬度試験はフィッシャー硬度計（ＨＰ１００－ＸＹｐ、フィッシャーインストルメンツ社製）を用いて行った。測定サンプルは先に記載のブルーレイディスクの作成において、ハードコート層を設けない以外は、同様にして作成したブルーレイディスクを用いた。測定方法としては１０００ｍＮの加重を６０秒かけ、その後加重を取り除いて（０ｍＮ）、加重を取り除いた（０ｍＮ）直後の押し込み深さ（最も深い押し込み深さ）を測定した（２５℃、４５％ＲＨ）。単位はμｍである。 (Hardness test)
The hardness test was performed using a Fischer hardness tester (HP100-XYp, manufactured by Fischer Instruments). As a measurement sample, a Blu-ray disc produced in the same manner as described above was used except that a hard coat layer was not provided. As a measuring method, a load of 1000 mN was applied for 60 seconds, then the weight was removed (0 mN), and the indentation depth (the deepest indentation depth) immediately after the weight was removed (0 mN) was measured (25 ° C., 45% RH). ). The unit is μm.
（復元性試験）
　復元性試験はフィッシャー硬度計（ＨＰ１００－ＸＹｐ、フィッシャーインストルメンツ社製）を用いて行った。測定サンプルは先に記載のブルーレイディスクの作成において、ハードコート層を設けない以外は、同様にして作成したブルーレイディスクを用いた。測定方法としては１０００ｍＮの加重を６０秒かけ、加重を取り除いた（０ｍＮ）直後の押し込み深さと、加重を取り除いて（０ｍＮ）６０秒経過した後の形成された硬化膜の窪み深さを測定した（２５℃、４５％ＲＨ）。復元性は前者の値と後者の値の差、即ち、下記式で求められる値により測定した。単位はμｍである。
復元性＝加重を取り除いた後６０秒経過した後の押し込み深さ－加重を取り除いた（０ｍＮ）直後の押し込み深さ (Restorability test)
The resilience test was performed using a Fischer hardness tester (HP100-XYp, manufactured by Fischer Instruments). As a measurement sample, a Blu-ray disc produced in the same manner as described above was used except that a hard coat layer was not provided. As a measuring method, a load of 1000 mN was applied for 60 seconds, and the indentation depth immediately after removing the weight (0 mN) and the depth of depression of the formed cured film after 60 seconds after removing the weight (0 mN) were measured. (25 ° C., 45% RH). Restorability was measured by the difference between the former value and the latter value, that is, the value obtained by the following equation. The unit is μm.
Restorability = indentation depth after 60 seconds after removal of weight-indentation depth immediately after removal of weight (0 mN)
（初期反り試験）
　初期反りは実施例または比較例の紫外線硬化型樹脂組成物の塗布前の基板の反りと塗布して硬化した後の反りの差を測定して評価した。
初期反り変化量＝硬化後の反り－紫外線硬化型樹脂組成物塗布前の基板の反り
○・・・±０．６度未満
×・・・±０．６以上 (Initial warpage test)
The initial warpage was evaluated by measuring the difference between the warpage of the substrate before application of the UV curable resin composition of the example or the comparative example and the warpage after application and curing.
Initial warpage variation = Warpage after curing-Warpage of substrate before application of UV curable resin composition ○ ... Less than ± 0.6 degrees ×… ± 0.6 or more
（ブルーレイディスクの耐久性試験）
　耐久性後反りは実施例または比較例の紫外線硬化型樹脂組成物の塗布前の基板の反りと、環境試験後の反り（塗布して硬化した後、８０℃、８５％ＲＨ（相対湿度）環境下、２５０時間放置後、室温で３日間放置したものの反り）の差（下記式で求められる値）を測定して評価した。単位は「度」である。
初期反り変化量＝環境試験後の反り－紫外線硬化型樹脂組成物塗布前の基板の反り
○・・・±０．６度未満
×・・・±０．６以上 (Durability test of Blu-ray Disc)
Durability warpage is the warpage of the substrate before application of the UV curable resin composition of the example or comparative example, and warpage after environmental test (80 ° C., 85% RH (relative humidity) environment after application and curing). Below, after leaving for 250 hours, the difference (the value calculated | required by the following formula) of the curvature of what was left at room temperature for 3 days was measured and evaluated. The unit is “degree”.
Initial warpage change = Warpage after environmental test-Warpage of substrate before application of UV curable resin composition ○ ・ ・ ・ less than ± 0.6 degrees × ・ ・ ・ ± 0.6 or more
（硬化性試験）
　トラックピッチ０．３２μｍの案内溝を有する直径１２ｃｍ、厚み１．１ｍｍのポリカーボネート基板をスピンテーブルに乗せ、内径１１．５ｍｍまで覆う様に円状のキャップ処理を行い、ついで実施例または比較例の紫外線硬化型樹脂組成物を３．０ｇ中心部のキャップ上に供給した。９００ｒｐｍの速度範囲で４秒から７秒間スピンコートし、塗布膜厚が９５μｍとなるよう塗布した。スピンコート終了間際にキセノンフラッシュランプを２ショット照射し、表面の流動性が無くなる程度に硬化させた後、高圧水銀ランプを使用し、上側から４００ｍＪ／ｃｍ2で３秒間照射して本発明の紫外線硬化型樹脂組成物を完全硬化させた。ポリカーボネート基板から剥離した硬化塗膜（重量：Ｗ１）をメチルエチルケトン中で８０℃にて９時間還流した後、８０℃で４時間乾燥後に秤量（重量：Ｗ２）し、ゲル分率を測定した。
ゲル分率＝Ｗ２×１００／Ｗ１ (Curing test)
A polycarbonate substrate having a diameter of 12 cm and a thickness of 1.1 mm having a guide groove with a track pitch of 0.32 μm is placed on a spin table, and a circular cap treatment is performed so as to cover the inner diameter of 11.5 mm. The curable resin composition was supplied onto a cap at the center of 3.0 g. Spin coating was performed at a speed range of 900 rpm for 4 to 7 seconds, and the coating film thickness was 95 μm. The xenon flash lamp is irradiated for 2 shots just before the end of spin coating and cured to such an extent that the surface fluidity is lost. Then, the high-pressure mercury lamp is used to irradiate from the upper side at 400 mJ / cm 2 for 3 seconds. The curable resin composition was completely cured. The cured coating film (weight: W1) peeled from the polycarbonate substrate was refluxed in methyl ethyl ketone at 80 ° C. for 9 hours, dried at 80 ° C. for 4 hours, weighed (weight: W2), and the gel fraction was measured.
Gel fraction = W2 × 100 / W1
　表１の結果より、実施例１～９の本発明の樹脂組成物は、何れもガラス転移温度Ｔｇが４０℃以上であり、初期反りの変化量及び耐久試験後の反り変化量共に、０．６未満の値となっており、何れも現在の高い水準で要求されている許容範囲の値となっている。なお、現在の技術水準において、反りの変化量が０．６度を超すと、エラーが急激に増加すると言われている。一方、比較例においては、何れか一方は満たすが、他方は許容範囲外となっており、現在の高い要求水準に対しては、問題が残る。
　また、本発明の実施例のなかでも、使用環境への対応と言う観点、特に夏時等の高温時期や通常想定されるよりも高温で保管される常態においては、温度が高いため、Ｔｇ温度が高い方が好ましく、実施例２に比べると、実施例１の方が好ましく、実施例８はより好ましく、Ｔｇが５０℃以上の実施例４～７は更に好ましく、Ｔｇが６０℃以上の実施例４，５及び７は最も好ましい。また、Ｔｇの値と共に、５０℃での弾性率（５０℃　Ｅ、Ｍｐａ）も３５Ｍｐａ以上であれば現在の要求水準を満たすが、出来れば、４５Ｍｐａ以上が好ましく、より好ましくは１００Ｍｐａ以上であり、更に好ましくは３００Ｍｐａ以上であり、最も好ましくは４５０Ｍｐａ以上である。
　また、初期反りの変化量及び耐久試験後の反り変化量共に、上記の要求されている許容範囲内であれば一応現在の要求はカバーするが、急激に高まる要求水準に対応し、よりエラーを減少させる意味では、両者の値が０．５以下が好ましく、０．４以下が更に好ましい。
　また、硬度試験では、上記表１の値が、好ましくは５４以下であり、より好ましくは５１以下であり、最も好ましくは４０以下である。また、復元性の値は、好ましくは４以上であり、５以上がより好ましく、更に、好ましくは６以上である。
　本発明の上記実施例の樹脂組成物は、硬化性に優れ、Ｔｇも高く、５０℃での弾性率も高い硬化物を与え、且つ、ブルーレイディスクに適用した場合、硬化時における反りの変化量も少ない。また、その硬化物層を有するブルーレイディスクは、湿度変化、温度変化による反りの変化量が少ないことから、該硬化物層は反りの変化量の抑制機能に優れ、耐久性にも優れる。従って、本発明の硬化型樹脂組成物は、ブルーレイディスクに、その硬化物層（好ましくは光透過層）を形成することにより、上記の優れた性質を有するブルーレイディスクとすることが出来る。 From the results shown in Table 1, all of the resin compositions of the present invention of Examples 1 to 9 have a glass transition temperature Tg of 40 ° C. or higher, and both the amount of change in initial warpage and the amount of warpage after the durability test are 0. The values are less than 6, and all are acceptable values required at the current high level. In the current technical level, it is said that when the amount of change in warpage exceeds 0.6 degrees, the error increases rapidly. On the other hand, in the comparative example, either one is satisfied, but the other is out of the allowable range, and the problem remains with respect to the current high requirement level.
Further, among the embodiments of the present invention, the Tg temperature is high because the temperature is high in the viewpoint of adapting to the use environment, in particular, in a high temperature period such as summer time or in a normal state where it is stored at a higher temperature than normally assumed. Higher than that of Example 2, Example 1 is more preferable, Example 8 is more preferable, Examples 4 to 7 having Tg of 50 ° C. or higher are more preferable, and Tg is 60 ° C. or higher. Examples 4, 5 and 7 are most preferred. In addition to the value of Tg, the elastic modulus at 50 ° C. (50 ° C. E, Mpa) satisfies the current required level if it is 35 Mpa or more, preferably 45 Mpa or more, more preferably 100 Mpa or more, More preferably, it is 300 Mpa or more, Most preferably, it is 450 Mpa or more.
Also, if both the amount of change in initial warpage and the amount of change in warpage after endurance testing are within the required tolerances, the current request will be covered for the time being. In the sense of decreasing, both values are preferably 0.5 or less, and more preferably 0.4 or less.
In the hardness test, the value in Table 1 is preferably 54 or less, more preferably 51 or less, and most preferably 40 or less. Further, the restoring value is preferably 4 or more, more preferably 5 or more, and further preferably 6 or more.
The resin compositions of the above examples of the present invention give a cured product having excellent curability, high Tg, and high elastic modulus at 50 ° C., and when applied to a Blu-ray Disc, the amount of change in warping upon curing. There are few. In addition, since a Blu-ray disc having the cured product layer has a small amount of warpage change due to changes in humidity and temperature, the cured product layer has an excellent function of suppressing the amount of change in warpage and is excellent in durability. Therefore, the curable resin composition of the present invention can be a Blu-ray disc having the above-mentioned excellent properties by forming a cured product layer (preferably a light transmitting layer) on the Blu-ray disc.

Claims (18)

  1. 　ブルーレイディスク用紫外線硬化型樹脂組成物中に、（ｉ）グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物を反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）、（ｉｉ）単官能（メタ）アクリレート化合物（Ｂ）及び（ｉｉｉ）光重合開始剤（Ｃ）を含有し、該樹脂組成物の総量１００重量部に対する、前記エポキシ（メタ）アクリレート（Ａ）の含有割合が３０重量部以上であり、その含有割合をＡ重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合をＢ重量部とした時、Ａ／Ｂが０．８～１．４５である該樹脂組成物の硬化物層を有するブルーレイディスク。 Epoxy (meth) acrylate (A) obtained by reacting (i) a glycidyl ether type epoxy compound and a (meth) acrylate compound having a carboxy group in an ultraviolet curable resin composition for Blu-ray Disc, (ii) The monofunctional (meth) acrylate compound (B) and (iii) the photopolymerization initiator (C) are contained, and the content of the epoxy (meth) acrylate (A) is 30 with respect to 100 parts by weight of the total amount of the resin composition. When the content ratio is A parts by weight and the content ratio of the monofunctional (meth) acrylate compound (B) is B parts by weight, A / B is 0.8 to 1.45. A Blu-ray disc having a cured product layer of the resin composition.
  2. 　グリシジルエーテル型エポキシ化合物とカルボキシ基を有する（メタ）アクリレート化合物とを反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）、単官能（メタ）アクリレート化合物（Ｂ）及び光重合開始剤（Ｃ）を含有するブルーレイディスク用紫外線硬化型樹脂組成物であって、該樹脂組成物の総量１００重量部に対する、前記エポキシ（メタ）アクリレート（Ａ）の含有割合が３０重量部以上であり、その含有割合をＡ重量部とし、前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合をＢ重量部とした時、Ａ／Ｂが０．８～１．４５であるブルーレイディスク用紫外線硬化型樹脂組成物。 Epoxy (meth) acrylate (A), monofunctional (meth) acrylate compound (B) and photopolymerization initiator (C) obtained by reacting a glycidyl ether type epoxy compound with a (meth) acrylate compound having a carboxy group ) Containing an ultraviolet curable resin composition for Blu-ray Disc, wherein the content of the epoxy (meth) acrylate (A) is 30 parts by weight or more with respect to 100 parts by weight of the total amount of the resin composition. An ultraviolet curable resin composition for Blu-ray Disc having an A / B of 0.8 to 1.45 when the proportion is A parts by weight and the content of the monofunctional (meth) acrylate compound (B) is B parts by weight. object.
  3. 　カルボキシ基を有する（メタ）アクリレート化合物が、（ａ）不飽和カルボン酸またはその誘導体、または、（ｂ）ヒドロキシ（メタ）アクリレート化合物のラクトン付加物（ｂ１）と多塩基酸無水物（ｂ２）から得られる化合物であることを特徴とする請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 A (meth) acrylate compound having a carboxy group is obtained from (a) an unsaturated carboxylic acid or a derivative thereof, or (b) a lactone adduct (b1) of a hydroxy (meth) acrylate compound and a polybasic acid anhydride (b2). The ultraviolet curable resin composition for Blu-ray Discs according to claim 2, which is a compound obtained.
  4. 　グリシジルエーテル型エポキシ化合物が、下記式（２）
    式（２）
    Figure JPOXMLDOC01-appb-I000006
    （式中、ｎは０～２０の整数を示す。）
    で表され、かつ、エポキシ当量が１８０ｇ／ｅｑ．～２００ｇ／ｅｑ．である液状グリシジルエーテル型エポキシ化合物であることを特徴とする請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。     The glycidyl ether type epoxy compound is represented by the following formula (2)
    Formula (2)
    Figure JPOXMLDOC01-appb-I000006
    (In the formula, n represents an integer of 0 to 20.)
    And an epoxy equivalent of 180 g / eq. ~ 200 g / eq. The ultraviolet curable resin composition for Blu-ray Disc according to claim 2, which is a liquid glycidyl ether type epoxy compound.
  5. 　単官能（メタ）アクリレート化合物（Ｂ）がベンゼン環を有する（メタ）アクリレート化合物又はジシクロペンテニル基又はジシクロペンタジエン基を有する（メタ）アクリレート化合物である請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The ultraviolet curing for Blu-ray Disc according to claim 2, wherein the monofunctional (meth) acrylate compound (B) is a (meth) acrylate compound having a benzene ring or a (meth) acrylate compound having a dicyclopentenyl group or a dicyclopentadiene group. Mold resin composition.
  6. 　前記単官能（メタ）アクリレート化合物（Ｂ）として、下記式（１）
    式（１）
    Figure JPOXMLDOC01-appb-I000007
    （式中、ｎは１～１０の整数を示す。）
    で表される化合物を含有することを特徴とする請求項２に記載の紫外線硬化型樹脂組成物。     As the monofunctional (meth) acrylate compound (B), the following formula (1)
    Formula (1)
    Figure JPOXMLDOC01-appb-I000007
    (In the formula, n represents an integer of 1 to 10.)
    The ultraviolet curable resin composition of Claim 2 containing the compound represented by these.
  7. 　前記式（１）においてｎが２である請求項６に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The ultraviolet curable resin composition for Blu-ray Disc according to claim 6, wherein n is 2 in the formula (1).
  8. 　ブルーレイディスク用紫外線硬化型樹脂組成物の総量１００重量部に対する、式（１）で表される化合物の含有割合、又は、単官能（メタ）アクリレート化合物（Ｂ）として、式（１）で表される化合物と共に、更に、ジシクロペンテニルオキシエチル（メタ）アクリレートを含む場合はその両者の合計含有割合、をＢ１重量部とした時、Ａ／Ｂ１が０．８～１．４５である請求項６に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The content ratio of the compound represented by the formula (1) or the monofunctional (meth) acrylate compound (B) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition for Blu-ray Disc is represented by the formula (1). A / B1 is 0.8 to 1.45 when the total content of dicyclopentenyloxyethyl (meth) acrylate is further B1 parts by weight when the compound further contains dicyclopentenyloxyethyl (meth) acrylate. 4. An ultraviolet curable resin composition for Blu-ray Discs.
  9. 　更に、ウレタン（メタ）アクリレートを、前記紫外線硬化型樹脂組成物の総量１００重量部に対し、２０重量部以下の割合で含有することを特徴とする請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 Furthermore, urethane (meth) acrylate is contained in the ratio of 20 weight part or less with respect to 100 weight part of total amounts of the said ultraviolet curable resin composition, The ultraviolet curable type for Blu-ray Discs of Claim 2 characterized by the above-mentioned. Resin composition.
  10. 　エポキシ（メタ）アクリレート（Ａ）が、下記式（２）
    Figure JPOXMLDOC01-appb-I000008
    （式中ｎは１～１０の整数を示す）
    で表されるグリシジルエーテル型エポキシ化合物と（メタ）アクリル酸とを反応させることにより得られたエポキシ（メタ）アクリレート（Ａ）である請求項６に記載のブルーレイディスク用紫外線硬化型樹脂組成物。     Epoxy (meth) acrylate (A) is represented by the following formula (2)
    Figure JPOXMLDOC01-appb-I000008
    (Where n represents an integer of 1 to 10)
    The ultraviolet curable resin composition for Blu-ray Discs according to claim 6, which is an epoxy (meth) acrylate (A) obtained by reacting a glycidyl ether type epoxy compound represented by the formula (II) with (meth) acrylic acid.
  11. 　前記紫外線硬化型樹脂組成物の総量１００重量部に対して、エポキシ（メタ）アクリレート（Ａ）の含量割合Ａ重量部と前記単官能（メタ）アクリレート化合物（Ｂ）の含有割合Ｂ重量部との合計が、少なくとも８０重量部である請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The content ratio A part by weight of the epoxy (meth) acrylate (A) and the content ratio B part by weight of the monofunctional (meth) acrylate compound (B) with respect to 100 parts by weight of the total amount of the ultraviolet curable resin composition The ultraviolet curable resin composition for Blu-ray Disc according to claim 2, wherein the total is at least 80 parts by weight.
  12. 　ブルーレイディスク用紫外線硬化型樹脂組成物の硬化物のガラス転移温度Ｔｇが少なくとも４０℃である請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The ultraviolet curable resin composition for Blu-ray Discs according to claim 2, wherein the cured product of the ultraviolet curable resin composition for Blu-ray Discs has a glass transition temperature Tg of at least 40 ° C.
  13. 　ブルーレイディスク用紫外線硬化型樹脂組成物に紫外線を照射し、紫外線照射後に形成される硬化物の５０℃における弾性率が４５０～１５００ＭＰａである請求項２に記載のブルーレイディスク用紫外線硬化型樹脂組成物。 The ultraviolet curable resin composition for Blu-ray Disc according to claim 2, wherein the ultraviolet curable resin composition for Blu-ray Disc is irradiated with ultraviolet rays, and the cured product formed after the ultraviolet irradiation has an elastic modulus at 50 ° C of 450 to 1500 MPa. .
  14. 　請求項１～１３のいずれか一項に記載のブルーレイディスク用紫外線硬化型樹脂組成物を硬化した硬化物。 A cured product obtained by curing the ultraviolet curable resin composition for Blu-ray Disc according to any one of claims 1 to 13.
  15. 　請求項１～１３のいずれか一項に記載の紫外線硬化型樹脂組成物に活性エネルギー線を照射して得られる硬化物。 A cured product obtained by irradiating the ultraviolet curable resin composition according to any one of claims 1 to 13 with active energy rays.
  16. 　光ディスク基板に、請求項１～１３のいずれか一項に記載の紫外線硬化型樹脂組成物を塗布し、活性エネルギー線を照射して得られる光透過層を有するブルーレイディスク。 A Blu-ray disc having a light transmission layer obtained by applying the ultraviolet curable resin composition according to any one of claims 1 to 13 to an optical disc substrate and irradiating active energy rays.
  17. 　光ディスク基板が、反射層を有する光ディスク基板である請求項１６に記載のブルーレイディスク。 The Blu-ray disc according to claim 16, wherein the optical disc substrate is an optical disc substrate having a reflective layer.
  18. 　請求項１４に記載の硬化物のガラス転移温度Ｔｇが少なくとも４０℃で、該硬化物の層を有するブルーレイディスクの初期の反りの変化量、及び、８０℃で、相対湿度８５％の環境下に２５０時間曝した後の耐久試験後の反りの変化量の両者の値が、何れも±０．６度未満である請求項１６に記載のブルーレイディスク。 The glass transition temperature Tg of the cured product according to claim 14 is at least 40 ° C, the amount of change in the initial warp of the Blu-ray Disc having the layer of the cured product, and at 80 ° C in an environment with a relative humidity of 85%. The Blu-ray disc according to claim 16, wherein both values of the amount of change in warpage after the durability test after exposure for 250 hours are both less than ± 0.6 degrees.
PCT/JP2013/003183 2012-05-22 2013-05-20 Ultraviolet curable resin composition and blu-ray disc WO2013175754A1 (en)

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