TW201302943A - Ultraviolet-curable type resin composition - Google Patents

Abstract

The present invention relates to an ultraviolet-curable type resin composition for BD (blue disk), including: (A) 5 to 15 parts by weight of a compound represented by the following formula (1) (R1 represents a linear alkylene containing a carbon number of 4 to 10, an alkylene group that contains a carbon number of 4 to 10 and ether bonding, or abranched alkylene containing a carbon number of 4 to 10, R11 represents a hydrogen atom or methyl group), (B) 10 to 60 parts by weight of a compound represented by the following formula (2) (wherein, R21 represents a hydrogen atom or methyl group, n represents an integer of 1 to 10), (C) 30 to 60 parts by weight of an urathane(meth)acrylate of a reactant of polytetramethyleneglycol, polyisocyanate and hydroxyC2-C4 alkyl (meth)acrylate, and (D) 2 to 8 parts by weight of a photo polymerization initiator. The ultraviolet-curable type resin composition of the present invention provides a light transparent layer with less warping during curing, and excellent durability under the environment with high humidity and temperature, which can provide a BD with less deterioration of light reflection even under the environment with high humidity and temperature.

Description

Ultraviolet curing resin composition

The present invention relates to an ultraviolet curable resin composition for a light transmissive layer of a Blu-ray disc and a disc for using the ultraviolet curable resin composition as a light transmissive layer, the Blu-ray disc having at least a light reflecting layer and light formed thereon The layer is penetrated, and a blue laser having an oscillation wavelength in the range of 370 nm to 430 nm is recorded or played through the aforementioned light penetrating layer.

In recent years, the transmission of large-capacity information records has been frequently carried out due to the development of information technology and information networks. It is followed by high-density, large-capacity optical discs that can record and play large-capacity music and computer data. A DVD (Digital Versatile Disc) which is widely used as a high-density recording medium uses a laser having a shorter wavelength than a CD (Compact Disc) in order to achieve higher density, and the optical system also has a high numerical aperture. However, since recording or playback of high-definition images corresponding to HDTV (high definition television) requires higher density, a method of recording higher density in the next generation position of the DVD and a review of the optical disc are proposed and used. High-density recording method for new optical disc construction of blue laser optical systems with shorter wavelengths than DVD.

The new optical disc is formed on a transparent or opaque substrate formed of a plastic such as polycarbonate to form an information recording portion such as a pit or an information recording layer, and then a light-transmissive layer of about 100 μm is laminated on the information recording portion. Recording light or playing light, or both are incident through the light penetrating layer The constructed disc. From a production point of view, the light transmissive layer of the optical disc is focused on the study of the use of an ultraviolet curable resin composition.

Thus, in a disc (blue light disc, hereinafter referred to as BD) that is recorded or played by a blue laser, the light transmissive layer is thicker than the user of the DVD, and the light transmissive layer is constructed as a DVD-9. The intermediate layer is used differently, and a light penetrating layer is provided in the vicinity of the surface layer or the surface layer. Therefore, even if the ultraviolet curable resin composition for the optical disc to which the conventional DVD is applied is directly transferred to the Blu-ray disc, the reliability of recording and playback due to skew or corrosion of the light reflection layer is remarkably reduced as compared with the DVD. Furthermore, it is necessary to have light transmittance for allowing short-wavelength light to pass through for a long period of time, and high hardness for use in the vicinity of the surface layer or the surface layer. Further, in view of productivity, it is required to be suitable for making a thick film. Composition.

An ultraviolet curable resin composition which can bend a disc to a small extent, for example, an ultraviolet curable resin composition containing an urethane (meta) acrylate which exhibits an amine ester (meth) acrylate A monomer obtained by reacting a lactone compound in a hydroxyl group-containing (meth) acrylate with a polyisocyanate compound (see Patent Document 1). In the ultraviolet curable resin composition, an amine ester (meth) acrylate having excellent flexibility is used, and this is an ultraviolet curable resin composition for use as a protective coating agent having a low curing shrinkage ratio and a low viscosity. However, when this composition is used as a light-transmitting layer for BD, the viscosity is low, and it is difficult to form a thick film. Further, in order to increase the viscosity and increase the content of the amine ester (meth) acrylate to form a light-transmitting layer of the optical disk, there is a problem that deterioration occurs due to corrosion of the metal film or the like in a high-temperature and high-humidity environment.

In addition, as a composition of a resin film which is less corrosive to the metal film of the recording medium, a resin composition containing a high specific gravity liquid oligomer having a specific gravity of 1.10 or more has been disclosed (see Patent Document 2). This composition uses an epoxy acrylate having a low moisture permeability, and particularly a high specific gravity liquid oligomer such as a bisphenol A type epoxy acrylate, thereby suppressing corrosion of the metal thin film and having The effect of discoloration of the recording medium is reduced. However, since the oligomer has a rigid skeleton, the surface layer of the recording medium is particularly curved when used as a light-transmitting layer for BD, resulting in a decrease in reliability of the recording medium.

On the other hand, an active energy curable composition used as an optical article having a ruthenium action or a lens action has been disclosed to include an amine ester (meth) acrylate having three (meth) acrylonitrile groups in a molecule, A composition having three (meth) acrylonitrile-based (meth) acrylates in the molecule (see Patent Document 3). This composition imparts a cured film excellent in curling property, shape maintaining property, transparency, surface hardness, and the like when laminated with a resin film, but has an aminoester (meth)acrylic acid having three (meth)acryl fluorenyl groups in its molecule. The ester, a composition comprising a (meth) acrylate having three (meth) acrylonitrile groups in the molecule, if used as a light transmissive layer of a disc, has an adhesion to a metal reflective layer as a light reflecting layer. Low problem. Further, in the case of (meth) acrylate having three (meth) acrylonitrile groups, those having EO or PO modification have adhesion to the metal reflective layer, but have high hydrophilicity due to a large number of hydrophilic structures. There is a problem with durability.

In order to meet the characteristics required for optical discs, various ultraviolet curable resins have been proposed which focus on the specific properties of durability or adhesion. Composition (Patent Documents 4 to 10). However, in the ultraviolet curable resin composition, when hardness is required, the bending at the time of hardening tends to become large, and it is found that the improvement of specific physical properties deteriorates other physical properties, and therefore it is expected to be developed to satisfy all market demands. A resin that requires properties.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open No. 11-12495

Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 11-302309

Patent Document 3: Japanese Patent Laid-Open Publication No. 2002-69139

Patent Document 4: Japanese Laid-Open Patent Publication No. 2005-243109

Patent Document 5: Japanese Laid-Open Patent Publication No. 2006-249228

Patent Document 6: JP-A-2009-32302

Patent Document 7: Japanese Laid-Open Patent Publication No. 2009-32303

Patent Document 8: International Publication No. 2008/099666

Patent Document 9: Japanese Patent Laid-Open Publication No. 2000-345073

Patent Document 10: International Publication No. 2009/144926

An object of the present invention is to provide an ultraviolet curable resin composition and a disc having a small decrease in light reflectance in a high-temperature and high-humidity environment, wherein the ultraviolet curable resin composition has less bending during curing and is excellent in durability in a high-temperature and high-humidity environment. .

It has been found in the present invention that it is contained as a difunctional (methyl) propyl group in a specific ratio. a compound represented by the following formula (1), a compound represented by the following formula (2) as a monofunctional (meth) acrylate, and a polytetramethylene as an amine ester (meth) acrylate. A composition of an amine ester (meth) acrylate of a reaction of a diol with a polyisocyanate and a C2 to C4 alkyl (meth)acrylate, by applying a hardened film of the composition to a light penetrating layer, The present invention has been completed by suppressing discoloration (yellowing, etc.) of a light-transmitting layer under high temperature and high humidity, reducing reflectance, whitening due to corrosion or oxidation of a metal film, and reducing occurrence of bending which causes deterioration of characteristics.

(wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group.)

(wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10.)

Further, the optical disk of the present invention having such a cured film excellent in durability as a light-transmitting layer is less likely to cause a decrease in light reflectance due to discoloration and bending even under high temperature and high humidity, and deterioration of signal characteristics is small. It is useful to record/play good information by short-wavelength blue laser.

The present invention relates to an ultraviolet curable resin composition for use in a light transmissive layer of BD, wherein the BD is provided with at least a light reflecting layer and a light penetrating layer on a substrate, and a blue laser is incident from the side of the light penetrating layer. Play the information.

In other words, the present invention relates to the following ultraviolet curable resin composition for BD, a cured product thereof, and a BD having a cured product thereof.

A blue light disc having a cured layer of the ultraviolet curable resin composition as a light transmissive layer on a substrate, wherein the ultraviolet curable resin composition is an ultraviolet curable resin composition for a Blu-ray disc, and the ultraviolet curable resin is cured. 100 parts by weight of the total amount of the resin composition, the following components (A) to (D) are contained in the following ratio, and (A) 5 to 15 parts by weight of the compound represented by the following formula (1) (wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group; (B) 10 to 60 parts by weight of the compound represented by the following formula (2) (wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10); (C) a reaction of polytetramethylene glycol, polyisocyanate, and a C2 to C4 alkyl (meth)acrylate 30 to 60 parts by weight of the amine ester (meth) acrylate; and (2) 2 to 8 parts by weight of the photopolymerization initiator.

2. The Blu-ray disc according to the above 1, wherein at least the light reflecting layer and the light penetrating layer are formed on the substrate, and the blue light having a vibration wavelength in the range of 370 nm to 430 nm passes through the light penetrating layer. Record or play.

3. An ultraviolet curable resin composition for a Blu-ray disc, which comprises the following components (A) to (D) in a ratio of 100 parts by weight based on the total amount of the ultraviolet curable resin composition, (A) 5 to 15 parts by weight of the compound represented by the formula (1) (wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group; (B) 10 to 60 parts by weight of the compound represented by the following formula (2) (wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10); (C) a reaction of polytetramethylene glycol, polyisocyanate, and a C2 to C4 alkyl (meth)acrylate 30 to 60 parts by weight of the amine ester (meth) acrylate; and (2) 2 to 8 parts by weight of the photopolymerization initiator.

4. The ultraviolet curable resin composition for a Blu-ray disc according to the above 3, wherein the compound represented by the above formula (1) is dipropylene glycol di(meth)acrylate or hexanediol di(meth)acrylate. Or both.

5. The ultraviolet curable resin composition for a Blu-ray disc according to the above 3 or 4, wherein the polytetramethylene glycol, the polyisocyanate, and the amine ester of the reactant of the (meth)acrylic acid hydroxy C2 to C4 alkyl ester ( In the methyl acrylate (C), the number average molecular weight of the polytetramethylene glycol used in the reaction is from 400 to 750.

6. The ultraviolet curable resin composition for a Blu-ray disc according to any one of the above-mentioned items 3 to 5, which is contained in an amount of 15 to 53 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition (E) a bisphenol A type di(meth)acrylate modified with 4 to 12 moles of ethylene oxide.

7. The ultraviolet curable resin composition for a Blu-ray disc according to any one of the above 3, wherein the compound represented by the following formula (3) is contained as an antioxidant. Wherein R ₂ , R ₃ and R ₄ are each independently present, R ₂ represents an alkyl group having 1 to 3 carbon atoms, R ₃ represents an alkylene group having 1 to 6 carbon atoms, and R ₄ represents a carbon number of 5 to 20 alkyl.)

8. The ultraviolet curable resin composition for a Blu-ray disc according to any one of the above 3, wherein the compound represented by the following formula (4) is contained as a silane coupling agent. (wherein R ₅ and R ₆ are each independently present, R ₅ represents an alkyl group having 1 to 3 carbon atoms, and R ₆ represents an alkylene group having 1 to 6 carbon atoms).

The ultraviolet curable resin composition for BD according to any one of the above 3 to 8, which contains (F) a compound having a hindered piperidine skeleton.

10. The ultraviolet curable resin composition for BD according to the above 9, wherein the compound (F) having a hindered piperidine skeleton is a compound having both a hindered piperidine skeleton and a (meth)acrylonitrile group.

11. The ultraviolet curable resin composition for a Blu-ray disc according to any one of the above 3 to 6, which contains at least 2,4,6-trimethylbenzhydrazene diphenylphosphine oxide (2,4,6- Trimethylbenzoyl diphenyl phosphine oxide) as a photopolymerization initiator (D).

12. The ultraviolet curable resin composition for a Blu-ray disc according to the above 6, which comprises a compound selected from the group consisting of (F) a hindered piperidine skeleton, a decane coupling agent represented by the above formula (4), and the above formula (3). Representing at least one of the groups of antioxidants.

The ultraviolet curable resin composition for a Blu-ray disc according to any one of the above 6 to 12, wherein at least 9 to 11 moles of bisphenol A type di(meth)acrylate of ethylene oxide is contained as ( E) A component having a content of 35 to 90 parts by weight based on 100 parts by weight of the component (C).

14. The use of the ultraviolet curable resin composition according to any one of the above 3 to 13, which is a light transmissive layer for forming a Blu-ray disc having a recording layer.

A cured product obtained by irradiating an active energy ray to the ultraviolet curable resin composition according to any one of the above 3 to 13.

A method for producing a BD having a recording layer, wherein the ultraviolet curable resin composition according to any one of the above 3 to 13 is applied onto a BD substrate, and the coating film is cured by irradiation of an active energy ray. Light penetrates the layer.

The ultraviolet curable resin composition for BD of the present invention can form a cured film having excellent curability, durability, and adhesion to a reflective layer or an interface layer. Further, the ultraviolet curable resin composition of the present invention has a small shrinkage ratio after hardening and long-term storage under low temperature conditions or high temperature conditions, and thus has The curvature generated in the BD having the cured film of the resin composition may be small. In addition, the BD having the cured film of the ultraviolet curable resin composition of the present invention as a light-transmitting layer can suppress discoloration (yellowing, etc.) of the light-transmitting layer even after being used for a long period of time in a high-temperature and high-humidity environment. The reflectance is lowered and whitening due to corrosion or oxidation of the metal film, so that information can be recorded/played well by short-wavelength blue laser. In addition, the BD having the cured film of the ultraviolet curable resin composition of the present invention as a light transmissive layer is excellent in restorability.

The ultraviolet curable resin composition of the present invention contains (A) 5 to 15 parts by weight of the compound represented by the following formula (1), and (B) 10 to 60 parts by weight of the compound represented by the following formula (2), (C) 30 to 60 parts by weight of the amine ester (meth) acrylate of the reaction of the polytetramethylene glycol with the polyisocyanate and the C 2 to C 4 alkyl (meth) acrylate, and (D) photopolymerization initiator 2 Up to 8 parts by weight.

(wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group)

(wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10)

In the present specification, "(meth) acrylate" means "methacrylate or acrylate". "(Meth)acrylic acid" is also the same.

In the present invention, the compound (A) represented by the following formula (1) (hereinafter referred to as "(A) component") is used as the bifunctional (meth) acrylate.

(wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group)

Here, the "alkyl group having an ether bond of 4 to 10 carbon atoms" means a group in which a plurality of alkylene groups are bonded by at least one ether bond (-O-), and a plurality of alkylene groups are formed. The carbon number of the base is 4 to 10.

In the compound (A) represented by the above formula (1), R ₁ is a linear alkyl group having 4 to 6 carbon atoms, an alkyl group having an ether bond of 4 to 6 carbon atoms, or a carbon number of 4 a compound having a branched alkyl group of up to 10.

Specific examples of the compound (A) represented by the above formula (1) include dipropylene glycol di(meth)acrylate and tripropylene glycol di(meth)acrylate. And hexanediol di(meth)acrylate. As the compound (A), either or both of dipropylene glycol di(meth)acrylate and hexanediol di(meth)acrylate are preferably used.

These compounds are commercially available, and specific examples thereof include Photomer 4226 (dipropylene glycol diacrylate, manufactured by Cognis Co., Ltd.), TPGDA (tripropylene glycol diacrylate (for example, manufactured by Daicel-cytec Co., Ltd.), and Photomer 4017 ( 1,6-hexanediol diacrylate, manufactured by Cognis Co., Ltd., and the like.

From the viewpoint of improving the restorability, the compound (A) represented by the above formula (1) is preferably a compound of the above formula (1) wherein R ₁ is a linear alkyl group having 4 to 10 carbon atoms. It is hexanediol diacrylate.

From the viewpoint of the improvement of the adhesion and the reduction of the bending at the time of hardening, as the compound (A) represented by the above formula (1), it is preferred that R ₁ in the above formula (1) has an ether bond of 4 to 10 carbon atoms. a compound having an alkylene group or a branched alkyl group having a carbon number of 4 to 10, more preferably dipropylene glycol di(meth)acrylate or tripropylene glycol di(meth)acrylate, particularly preferably Dipropylene glycol diacrylate.

In the present invention, the crosslinking density can be increased by containing the compound (A) represented by the above formula (1) in a specific ratio, and a hardened film having a hardness suitable for protecting BD can be formed.

The ultraviolet curable resin composition of the present invention has a formula (100 parts by weight based on the total amount of the ultraviolet curable resin composition) from the viewpoint of obtaining a cured product having a desired adhesiveness, resilience, and hardness. 1) The content of the compound (A) represented is usually 5 to 15 parts by weight, preferably 5 to 12 parts by weight. The amount is more preferably 5 to 7 parts by weight. When the amount of the component (A) is less than 5 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition, the curable property and the hardness are deteriorated, so that it is difficult to obtain a cured film having a desired performance. When the amount of the component (A) exceeds 15 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition, bending is likely to occur and the adhesion is lowered, so that it is not suitable for BD.

In the ultraviolet curable resin composition of the present invention, as the bifunctional (meth) acrylate which is suitable for use in combination with the component (A), bisphenol A type II which is modified by ethylene oxide 4 to 12 mol is exemplified. (Meth) acrylate (E) (hereinafter referred to as "(E) component"). The bisphenol A type di(meth)acrylate (E) is not particularly limited as long as it is known, and preferably bisphenol A type II modified by ethylene oxide 6 to 11 moles The (meth) acrylate is more preferably a bisphenol A type di(meth) acrylate modified with 9 to 11 moles of ethylene oxide.

A bisphenol A type di(meth)acrylate (E) modified with ethylene oxide 4 to 12 moles, for example, an ethylene oxide 4 molar modified bisphenol A type di(methyl) can be used. Acrylate (for example, BPE-4A manufactured by Daiichi Kogyo Co., Ltd.), bisphenol A-type di(meth)acrylate modified with 10 mol of ethylene oxide (for example, BPE manufactured by Daiichi Kogyo Co., Ltd.) -10, etc.).

When the above-mentioned bisphenol A type di(meth)acrylate (E) (or BPE 4 to 12 or simply (E)) modified with ethylene oxide 4 to 12 moles is used, the present invention is The total amount of the ultraviolet curable resin composition is 100 parts by weight, and the di(meth)acrylate (E) is contained in an amount of 15 to 53 parts by weight, whereby both the crosslinking density and the flexibility can be improved. From the perspective of improving durability The content of the bisphenol A type di(meth)acrylate (E) is preferably from 15 to 50 parts by weight, more preferably from 15 to 40 parts by weight.

The (E) component may be used singly or in combination of two or three. Depending on the case, it is sometimes preferred to use two types in combination. Preferably, the bisphenol A type di(meth)acrylate modified with ethylene oxide 4 to 8 moles and the bisphenol A type II modified with ethylene oxide 9 to 12 moles are preferably used. Base) acrylate. A preferred aspect is to use one or two of the components of the (E) component, for example, 100 parts by weight of bisphenol A type di(meth)acrylate modified with 9 to 11 moles of ethylene oxide. The aspect of the bisphenol A type di(meth) acrylate having an ethylene oxide 4 to 8 molar modification was used in a ratio of 0 to 100 parts by weight. In this case, it is particularly preferred to contain bisphenol A type di(meth)acrylic acid having 9 to 11 moles of ethylene oxide in an amount of 15 to 30 parts by weight based on 100 parts by weight of the total of the foregoing resin composition. ester.

When the content of the di(meth)acrylate (E) is too large, corrosion of the metal film is likely to occur under high temperature and high humidity. In addition, when the content of the di(meth)acrylate (E) is 15 parts by weight or more based on 100 parts by weight of the resin composition, sufficient flexibility can be imparted, which is preferable.

When the content of the amine ester (meth) acrylate (C) is 100 parts by weight, the component (E) is preferably a ratio of about 40 to 120 parts by weight. In the component (E), the bisphenol A type di(meth)acrylate having an ethylene oxide 9 to 11 molar modification is preferably 35 to 90 parts by weight, based on 100 parts by weight of the component (C). More preferably, it is a ratio of 40 to 80 parts by weight.

In the ultraviolet curable resin composition of the present invention, the compound (B) represented by the following formula (2) is used as the monofunctional (meth) acrylate (hereinafter referred to as It is "(B) ingredient").

(wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10.)

In the above formula (2), it is preferred that n is from 1 to 3. Specific examples of the compound (B) represented by the above formula (2) to be used are phenol (meth) acrylate modified with ethylene oxide, and more preferably 1 to 3 moles of ethylene oxide. The phenol (meth) acrylate is more preferably an oxirane 1 or 2 molar modified phenol (meth) acrylate. Such an ethylene oxide-modified phenol (meth) acrylate (B) is commercially available as a product, and specific examples thereof include Photomer 4035 (phenoxyethyl acrylate, n=1, manufactured by COGNIS Co., Ltd.). EBECRYL110 (epoxy acrylate 2 molar modified phenolic acrylate, n=2, produced by DAICEL-CYTEC AG).

Here, from the viewpoint of improving the restorability, phenol (meth) acrylate having an ethylene oxide 2 molar modification in which n is 2 in the above formula (2) is preferred.

Further, phenoxyethyl acrylate (n = 1) is also preferable because it is inexpensive and can obtain appropriate characteristics.

The content of the component (B) is usually preferably more than the content of the component (A). For example, when the content of the component (A) is 100 parts by weight, the content of the component (B) is more than 100 parts by weight. For example, it is about 102 to 600 parts by weight, more preferably about 105 to 500 parts by weight.

Further, when the content of the amine ester (meth) acrylate (C) is 100 parts by weight, the content of the component (B) is preferably about 20 to 100 parts by weight, more preferably 30. The ratio to about 90 parts by weight is more preferably about 30 to 80 parts by weight.

In the ultraviolet curable resin composition of the present invention, the compound represented by the above formula (2) is 100 parts by weight based on the total amount of the ultraviolet curable resin composition, from the viewpoint of adhesion, flexibility, and resilience. The content of (B) is usually 10 to 60 parts by weight, preferably 15 to 50 parts by weight, sometimes preferably 10 to 40 parts by weight, particularly preferably 20 to 40 parts by weight. When the content of the compound (B) is too small, the purpose of adhesion, flexibility, and restorability cannot be exhibited, and if it is too large, there is a problem that sufficient hardness cannot be obtained.

In the ultraviolet curable resin composition of the present invention, the reaction of polytetramethylene glycol with polyisocyanate and (meth)acrylic acid hydroxy C2 to C4 alkyl ester is used as the amine ester (meth) acrylate (C). Amine ester (meth) acrylate (hereinafter referred to as "(C) component"). When the amine ester (meth) acrylate (C) is used in an appropriate amount, it has a function of improving the mechanical properties (bending and skewing) of BD.

The amine ester (meth) acrylate (C) used in the present invention can be obtained by using polytetramethylene glycol (a), polyisocyanate (b), and (meth)acrylic acid hydroxy C2 to C4 alkyl ester ( c) obtained by reaction.

In order to obtain an amine ester (meth) acrylate excellent in balance between flexibility and hardness, the number average molecular weight of the polytetramethylene glycol (a) is preferably from 400 to 2,000, further from viscosity, cost, and adhesion. From the viewpoint of the use, it is preferred to use a number average molecular weight of 500 to 1000, particularly preferably a number of uses. The average molecular weight is from 500 to 750. It is sometimes preferred to use polytetramethylene glycol (a) having a number average molecular weight of from 400 to 750.

When the polytetramethylene glycol (a) to be used has a large number average molecular weight, the hardness of the cured product of the resin composition is deteriorated, which is not preferable. Further, when the number average molecular weight is too small, excellent flexibility cannot be imparted, and it is difficult to improve the mechanical properties (bending and skew) of the BD, which is not preferable.

The polyisocyanate (b) is not particularly limited as long as it is a compound having two or more isocyanate groups, and examples thereof include isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, xylene diisocyanate, and diphenyl group. Methane-4,4'-diisocyanate or dicyclopentene isocyanate.

In this case, it is preferred to use isophorone diisocyanate or toluene diisocyanate as the polyisocyanate (b).

Examples of the (meth)acrylic acid hydroxy group C2 to C4 alkyl ester (c) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate. Among them, hydroxyethyl (meth)acrylate is preferably used.

As the amine ester (meth) acrylate (C), it is preferred to use a polytetramethylene glycol (a) and a polyisocyanate (b) such that the isocyanate group equivalent of the polyisocyanate (b) is relative to the poly The hydroxyl equivalent of tetramethylene glycol (a) is reacted in an excess amount, and an amino ester oligomer having an isocyanate group at both ends is synthesized, and the obtained amine ester oligomer and hydroxyl group (meth)acrylic acid C2 to C4 are obtained. The amine ester (meth) acrylate obtained by the reaction of the alkyl ester (c).

The synthesis reaction of the amine ester (meth) acrylate can be carried out, for example, in the following manner. That is, the polytetramethylene glycol (a) and the polyisocyanate (b) are preferably 1.1 to 2.0 equivalents per 1 equivalent of the hydroxyl group and the isocyanate. The amine ester oligomer is synthesized by mixing at a reaction temperature of 70 to 90 ° C. Next, the obtained amine ester oligomer is mixed with a C2 to C4 alkyl (meth)acrylate (c), an isocyanate group of an amine ester oligomer per 1 equivalent of a (meth)acrylic acid C2 to C4 alkyl ester ( The hydroxyl group of c) is preferably mixed in an amount of from 1 to 1.5 equivalents, and is reacted at 70 to 90 ° C, whereby the desired amine ester (meth) acrylate can be obtained.

The molecular weight of the amine ester (meth) acrylate (C) used in the ultraviolet curable resin composition of the present invention preferably has a number average molecular weight of about 400 to 10,000.

In the ultraviolet curable resin composition of the present invention, the amine ester (meth) acrylate (C) is based on the total amount of the ultraviolet curable resin composition from the viewpoint of adhesion, flexibility, and improvement in recovery property. The content is usually from 30 to 60 parts by weight, preferably from 30 to 50 parts by weight. When the content is too small, the purpose of adhesion, flexibility, and restorability cannot be exhibited. When the content is too large, the problem that sufficient hardness cannot be obtained may occur, and the effect of the object of the present invention may not be exhibited, which is not preferable.

In the present invention, an amine ester (meth) acrylate other than the above amine ester (meth) acrylate (C) can be used in combination.

The amine ester (meth) acrylate which can be suitably used together can be obtained by reacting the polyol (d), the polyisocyanate (b) and the hydroxy (meth) acrylate compound (e).

Here, the polyisocyanate (b) can be used as described above.

Examples of the polyol (d) which can be used include the following polyols.

(i) neopentyl glycol, 3-methyl-1,5-pentanediol, propylene glycol, 1,4-butanediol, An aliphatic alcohol such as 1,6 hexanediol, trimethylolpropane, neopentyltetraol, tricyclodecane dimethylol or bis-[hydroxymethyl]-cyclohexane;

(ii) a polyester polyol obtained by reacting an aliphatic polyol according to the above (i) with a polybasic acid.

Further, examples of the polybasic acid include succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, sebacic acid, and tetrahydrophthalic anhydride.

(iii) a caprolactone obtained by reacting a polyol with ε-caprolactone.

(iv) Polycarbonate polyol. For example, a polycarbonate diol obtained by reacting 1,6-hexanediol with diphenyl carbonate.

(v) Polyester polyol. For example, polyethylene carbonate or ethylene oxide modified bisphenol A obtained by reacting a poly C2 to C3 alkanediol such as polyethylene glycol or polypropylene glycol with diphenyl carbonate.

In the above (ii) to (iv), the number average molecular weight of the polyol is preferably from about 200 to 8,000, more preferably from about 200 to 3,000.

Examples of the hydroxy (meth) acrylate compound (e) which can be used include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, and mono (methyl). ) dimethylolcyclohexyl acrylate, hydroxycaprolactone (meth) acrylate, and the like. Among them, hydroxyethyl (meth)acrylate is preferably used.

The amine ester (meth) acrylate other than the above amine ester (meth) acrylate (C) can be synthesized by the same method as described for the above amine ester (meth) acrylate (C).

When the amine ester (meth) acrylate other than the above amine ester (meth) acrylate (C) is used in combination, all of the above amine ester (meth) acrylate is added The content of the amine ester (meth) acrylate (C) is preferably 80% by weight or more, and more preferably 90% by weight or more.

Further, it is generally not necessary to use an amine ester (meth) acrylate other than the above amine ester (meth) acrylate (C), and it is preferred to use the above-mentioned amine ester (meth) acrylate (C) alone.

In the total amount of the resin composition of the present invention, 100 parts by weight, the total amount of the above (A) to (C) is usually 45 to 98 parts by weight, preferably 50 to 80 parts by weight, more preferably 55 to 75 parts by weight. . The remainder is the component (D) and any component, and more preferably the one containing the above (E) component as one of the components.

The photopolymerization initiator (D) (hereinafter referred to as "(D) component") is used in the ultraviolet curable resin composition of the present invention. In the present invention, the photopolymerization initiator (D) can be used as long as it is a known photopolymerization initiator, and examples thereof include benzoin isobutyl ether and 2,4-diethylthioxanthone (2,4-). Diethylthioxanthone), 2-isopropylthioxanthone, benzil, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzil dimethyl ketal, 2 -hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2-methyl-1 -(4-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one) and 2,4,6-three Molecular ring-opening photopolymerization initiators such as 2,4,6-trimethyl benzoyl diphenylphosphine oxide; and benzophenone and 4-phenyldiphenyl Ketone, isophthalphenone, 4-benzylidene-4'-methyl-diphenyl sulfide, etc. A dehydrogenation type photopolymerization initiator or the like. Preferred examples of the photopolymerization initiator include a molecular ring-opening type photopolymerization initiator such as 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzimidium diphenylphosphine oxide. These may be used alone or in combination of two or more.

Particularly, from the viewpoint of enhancing internal hardenability, the aspect of using 2,4,6-trimethylbenzimidium diphenylphosphine oxide is one of preferable ones. One of the more preferable aspects is, for example, a combination of the above-mentioned molecular ring-opening type photopolymerization initiator, preferably 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzimidium diphenylphosphine. Oxide.

When 2,4,6-trimethylbenzimidium diphenylphosphine oxide is used as the photopolymerization initiator (D), the content thereof is preferably from 3 to 50 by weight based on the total amount of the component (D). %.

The content of the photopolymerization initiator (D) in the ultraviolet curable resin composition is usually from 1 to 10 parts by weight, preferably from 2 to 8 parts by weight, based on 100 parts by weight based on the total amount of the ultraviolet curable resin composition. It is preferably from 3 to 8 parts by weight.

The ultraviolet curable resin composition of the present invention contains the components (A) to (D) in the above ratio, and may contain components other than (A) to (D) as the remainder.

The ultraviolet curable resin composition of the present invention preferably contains the component (E) in the above ratio in addition to (A) to (D). In the ultraviolet curable resin composition of the present invention, the content of the components other than the components (A) to (E) is 100 parts by weight based on the total amount of the ultraviolet curable resin composition of the present invention (when a plurality of components are contained, the total amount thereof is Amount) usually from 0 to 35 parts by weight, Preferably, it is from about 0 to about 10 parts by weight.

In the ultraviolet curable resin composition of the present invention, epoxy (meth) acrylate (G) (hereinafter referred to as "(G) component") can be used as necessary. Epoxy (meth) acrylate (G) has a function of improving hardenability, improving hardness and hardening speed of the cured product.

Further, the epoxy (meth) acrylate (G) can be used as long as it is obtained by reacting a epoxidized propyl ether type epoxy compound with (meth)acrylic acid. As the epoxy propyl ether type epoxy compound for obtaining a preferred epoxy (meth) acrylate, bisphenol A or an alkylene oxide adduct thereof may be mentioned. a diglycidyl ether of a bisphenol F or an alkylene oxide adduct thereof, a diglycidyl ether of hydrogenated bisphenol A or an alkylene oxide adduct thereof, hydrogenated bisphenol F or Epoxyalkylene adducts of diepoxypropyl ether, ethylene glycol diepoxypropyl ether, propylene glycol diepoxypropyl ether, neopentyl glycol diepoxypropyl ether, butanediol diepoxy Propyl ether, hexanediol diepoxypropyl ether, cyclohexane dimethanol diepoxypropyl ether, polypropylene glycol diepoxypropyl ether, and the like.

The epoxy propyl ether type epoxy compound and (meth)acrylic acid can be reacted under the following conditions to obtain an epoxy (meth) acrylate (G).

The (meth)acrylic acid is reacted at a ratio of 0.9 to 1.5 moles, preferably 0.95 to 1.1 moles, per equivalent of the epoxy group of the epoxy propyl ether type epoxy compound. The reaction temperature is preferably from 80 to 120 ° C, and the reaction time is from about 10 to 35 hours. In order to promote the reaction, it is preferred to use a catalyst such as triphenylphosphine, TAP, triethanolamine or tetraethanolammonium chloride. Further, in order to prevent polymerization in the reaction, for example, p-methoxyphenol or methyl hydrogen may be used. 醌 etc. as an anti-polymerization agent.

The epoxy (meth) acrylate (G) which can be suitably used in the present invention is exemplified by a bisphenol A type epoxy obtained by reacting a bisphenol A type epoxy compound with (meth)acrylic acid (A) Base) acrylate. In the present invention, the epoxy (meth) acrylate (G) preferably has a molecular weight of 500 to 10,000.

The ultraviolet curable resin composition of the present invention may optionally contain an epoxy (meth) acrylate (G). For example, from the viewpoint of ensuring flexibility and adhesion, it is usually from 0 to 20 parts by weight, more preferably from 0 to 10, per 100 parts by weight based on the total amount of the ultraviolet curable resin composition of the present invention. About the weight. It is generally preferred that the epoxy (meth) acrylate (G) is not contained.

In the ultraviolet curable resin composition of the present invention, the above (A) component, the component (B), the component (C), and the amine ester (meth)acrylate other than the component (C) may be used as appropriate. E) Component (meth) acrylate monomer (H) other than the above (G) component (hereinafter referred to as "(H) component"). Further, the (meth) acrylate monomer (H) does not include those included in the photosenabilizer and other additives described later.

The (meth) acrylate monomer (H) which can be used is not particularly limited as long as it is a compound having one or more (meth) acrylonitrile groups not contained in the above components.

For example, examples of the compound having one or more (meth)acrylinyl groups include isooctyl (meth)acrylate, isoamyl (meth)acrylate, dodecyl (meth)acrylate, and (methyl). Isodecyl acrylate, octadecyl (meth) acrylate, cetyl (meth) acrylate, isotetradecyl (meth) acrylate (5) C5 to C20 (preferably C7 to C18) alkyl esters of (meth)acrylic acid esters such as esters and tridecyl (meth)acrylate; benzyl (meth)acrylate and phenylepoxypropyl (meth)acrylate a (meth) acrylate having a benzene ring, or a tetrahydrofuran (meth) acrylate, which is not included in the compound represented by the above formula (2), such as an ester or a polypropylene oxide modified (meth) phenyl phenyl acrylate; And a (meth) acrylate having a hetero ring such as a morpholine (meth)acrylate; a C2 to C8 alkyl ester having a hydroxyl group (meth)acrylic acid such as 2-hydroxypropyl (meth)acrylate; and an ethoxy group Polyalkylene glycol mono(meth)acrylate such as ethylene glycol (meth) acrylate or polypropylene glycol (meth) acrylate; tricyclodecyl (meth) acrylate, (meth) acrylate Isobornyl (meta)acrylate, dicyclopentadienyloxyethyl (meth)acrylate, dicyclopentenyl acrylate (for example, FANCRYL FA-511A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentyl acrylate Alkenyloxyethyl ester (for example, FANCRYL FA-512A manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenyloxyethyl methacrylate (for example, Hitachi Chemical Co., Ltd.) FANCRYL FA-512M), dicyclopentanyl acrylate (such as FANCRYL FA-513A manufactured by Hitachi Chemical Co., Ltd.), and dicyclopentanyl methacrylate (for example, FANCRYL FA-513M manufactured by Hitachi Chemical Co., Ltd.) ), 1-adamantyl acrylate (for example, Adamantate AA manufactured by Idemitsu Kosan Co., Ltd.), 2-methyl-2-adamantyl acrylate (for example, Adamantate MA manufactured by Idemitsu Kosan Co., Ltd.), 2-ethyl-2-adamantyl acrylate (such as Adamantate EA manufactured by Idemitsu Kosan Co., Ltd.) and 1-adamantyl methacrylate (such as Adamantate AM manufactured by Idemitsu Kosan Co., Ltd.), etc., having C7 to C10 Aliphatic ring (meth) acrylate compound; epoxy Ethyl modified phenyl oxyphosphate (meth) acrylate, ethylene oxide modified (meth) acrylate butyl oxyphosphate, and ethylene oxide modified (meth) acrylate oxidized phosphate (methyl ) Acrylic phosphate and the like.

The (meth) acrylate monomer (H) having one (meth) acrylonitrile group may have a BD which enhances the light transmissive layer formed of the ultraviolet curable resin composition of the present invention, depending on the case. Mechanical properties (bending, skewing).

The (meth) acrylate monomer (H), as the (meth) acrylate monomer having two (meth) acrylonitrile groups, may be exemplified by cyclohexane-1,4-dimethanol. (meth) acrylate, cyclohexane-1,3-dimethanol di(meth) acrylate, tricyclodecane dimethylol di(meth) acrylate (for example, KAYARAD manufactured by Nippon Kayaku Co., Ltd.) a di(meth) acrylate compound having a C5 to C10 aliphatic ring such as R-684 (tricyclodecane dimethylol diacrylate) or the like; and dicyclopentene di(meth) acrylate; Alkanediol di(meth)acrylate (for example, KAYARAD R-604, manufactured by Nippon Kayaku Co., Ltd. a di(meth) acrylate compound having a heterocyclic ring such as an alkanediol diacrylate or the like; a compound represented by the above formula (1) excluding an alkylene glycol di(meth) acrylate or an epoxy extension thereof Alkyl modifiers such as (a) C2 or C3 diol di(meth) acrylate, ethylene oxide 3 to 10 moles modified 1,6-hexanediol di(meth) acrylate, epoxy extension Alkenyl 3 to 10 molar modified neopentyl glycol di(meth) acrylate such as alkyl (meth) acrylate and its alkylene oxide modification; hydroxypivalic acid neopentyl glycol di (methyl) Acrylate; polyethylene glycol di(meth)acrylate having a repeat number of 6 or more and polyalkylene glycol di(meth)acrylate having a repeat number of 4 or more and more than C10 Acrylate; an epoxy-alkylene modified bisphenol A type di(meth)acrylate other than the above-mentioned ethylene oxide 4 to 12 molar modified bisphenol A type di(meth)acrylate (E) ; and ethylene oxide modified di(meth)acrylic acid phosphate.

In this case, from the viewpoint of suppressing the amount of change in bending due to temperature change, the viewpoint of durability, and the improvement of hardness, it is preferred to use the above formula (1) to represent a di(meth)acrylic acid derived from a compound other than the compound (1). Ester or its alkylene oxide modification.

As the (meth) acrylate monomer (H), a (meth) acrylate monomer having three (meth) acrylonitrile groups may, for example, be trimethylolpropyl tri(meth)acrylate. And trimethylol C2 to C10 alkyl tris(meth)acrylate such as trimethylol octyl (meth)acrylate; trimethylolpropane polyethoxylate tris(meth)acrylate, tris(A) Tris(meth)acrylic acid trimethylol C2 to C10 alkane, such as trimethylolpropane polypropoxylate, and trimethylolpropane polyethoxypolypropoxy tri(meth)acrylate a polyalkoxy ester; and a [(meth)acryloyloxyethyl]isocyanurate, a neopentyl triol (meth) acrylate, a ring Ethylene oxide modified trimethylolpropane tri(meth)acrylate and propylene oxide modified trimethylolpropane tri(meth)acrylate, such as alkylene oxide modified trimethylolpropane tris(methyl) ) Acrylate and the like.

The (meth) acrylate monomer (H), as the (meth) acrylate monomer having four (meth) acrylonitrile groups, may be exemplified by tetrakis(meth)acrylic acid pentaerythritol. Ethoxylate, tetrapropanol tetrapropanol polypropoxylate, neopentyl alcohol tetra(meth) acrylate, bis(trimethylolpropane) tetra (a) Acrylate, dipentaerythritol tetra(meth)acrylate, and the like.

Regarding the (meth) acrylate monomer (H), as a (meth) acrylate monomer having five (meth) acrylonitrile groups, dine pentaerythritol penta (meth) acrylate may be mentioned. Wait.

Regarding the (meth) acrylate monomer (H), as a (meth) acrylate monomer having six (meth) acrylonitrile groups, dipentaerythritol hexa(meth) acrylate may be mentioned. Wait. Further, the (meth) acrylate monomer used in the present invention may be a polyfunctional group having seven or more (meth) acrylonitrile groups.

In the ultraviolet curable resin composition of the present invention, these (H) components may be used alone or in combination of two or more kinds in any ratio. The content of the (H) component in the ultraviolet curable resin composition is usually from 0 to 53 parts by weight, based on the total amount of the ultraviolet curable resin composition, and is, for example, from 20 to 80 parts by weight, preferably from 20 to 80 parts by weight. It is about 30 to 70 parts by weight.

Any one of an acrylate compound and a methacrylate compound can be used as the (meth) acrylate compound contained in the ultraviolet curable resin composition of the present invention. It is generally preferred to use an acrylate compound, and the total amount of the methacrylate compound contained in the resin composition is preferably less than 10 parts by weight based on 100 parts by weight of the total of the resin composition. In addition, the (meth) acrylate compound contained in the ultraviolet curable resin composition of the present invention means the component (A), the component (B), the component (C), and the component (C). An amine ester (meth) acrylate, the above (E) component, the above (G) component, and the (H) component of the resin composition (Meth) acrylate compound.

In the ultraviolet curable resin composition of the present invention, other additives such as a sensitizer, a decane coupling agent, a surfactant, a leveling agent, a thermostatic polymerization agent, and a hindered phenol may be used as necessary. And antioxidants such as phosphite, and light stabilizers such as hindered amines.

When the above additives are used, the additive content is 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total of the ultraviolet curable resin composition of the present invention.

In the ultraviolet curable resin composition of the present invention, as the sensitizer, for example, trimethylamine, methyldimethanolamine, triethanolamine, para-dimethylaminoacetophenone, or the like can be used. -ethyl dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine and 4,4'-bis(diethylamino)diphenyl Ketones, etc. Further, an amine which does not undergo an addition reaction with the photopolymerizable compound can be used in combination as a sensitizer.

From the viewpoint of rationality in the production of the optical disk, it is preferred to use a light stabilizer in the ultraviolet curable resin composition of the present invention, and the light stabilizer can utilize a hindered amine, especially a compound having a hindered piperidine skeleton (F) ) (hereinafter referred to as "(F) ingredient").

The compound (F) having a hindered piperidine skeleton is not particularly limited as long as it is a well-known one.

Specifically, for example, 2,2,6,6-tetramethyl-4-piperidone, 2,2,6,6-tetramethyl-4-piperidinol, 1,2,2,6 can be used. ,6-pentamethyl-4-piperidinol, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, (meth)acrylic acid 1,2,2,6,6- Pentamethyl-4-piperidinyl ester, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, bis(1,2,2,6,6-pentamethyl-sebacate) 4-piperidinyl ester, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, poly{[6-(1,1,3,3-tetramethylbutyl) Amine-1,3,5-three (triazine)-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imido]hexamethylene[[2,2,6,6-tetra Methyl-4-piperidinyl)imido]], dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate , 2-(3,5-di-t-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidine), hydrazine (2 , 2,6,6-tetramethyl-4-piperidinyl) 1,2,3,4-butane tetracarboxylate, 1,2,3,4-butane tetracarbonate and 1,2,2 , a mixed ester of 6,6-pentamethyl-4-piperidinol and 1-tridecanol, 1,2,3,4-butane tetracarbonate and 2,2,6,6-tetramethyl Mixed esterified product of 4-piperidinol and 1-tridecanol, 1,2,3,4-butane tetracarbonate and 1,2,2,6,6-pentamethyl-4-piperidinol And 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetra a mixed esterified product of 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, and 1 , 2,3,4-butane tetracarbonate with 2,2,6,6-tetramethyl-4-piperidinol and 3,9-bis(2-hydroxy-1,1-dimethylethyl) -2,4,8,10-four At least one hindered amine compound is selected from the group consisting of mixed esterified compounds of spiro[5,5]undecane. Among them, 1,2,2,6,6-pentamethyl-4-piperidinol, 2,2,6,6-tetramethyl-4-piperidyl can be suitably used from the viewpoint of imparting excellent durability. Pyridyl alcohol, 1,2,2,6,6-pentamethyl-4-piperidyl (meth)acrylate (LA-82, manufactured by ADEKA CORPORATION).

Among the above hindered amines (preferably the compound (F) having a hindered amine piperidine skeleton), hindered means that the molecule has a steric hindrance, and a bulky hydrocarbon group having a branched chain is bonded to the nitrogen atom or its adjacent On the carbon atom. The hindered amine compound to be used is preferably a compound having a hydrocarbon group having a branched chain such as a third butyl group bonded to a nitrogen atom, and for example, having a C1 to C3 alkane at least at the 1, 2, 2, 6, and 6 positions. A compound substituted with a hindered skeleton.

Further, when the ultraviolet curable resin composition of the present invention is used as a cured product, since the compound having a hindered amine skeleton crosslinks itself, it is less likely to be precipitated as an impurity, and the ultraviolet curable resin composition is not damaged. The hardenability is particularly suitable for the use of a compound having a hindered piperidine skeleton containing a (meth)acryl fluorenyl group. For example, it is preferred to have a C1 to C3 alkyl substituted piperidine (meth)acrylate at least at the 2, 2, 6, and 6 positions, more preferably 1,2,2,6,6-(meth)acrylic acid. Pentamethyl-4-piperidinyl ester.

The content of the photosensitizer (preferably the compound (F) having a hindered piperidine skeleton) in the ultraviolet curable resin composition is usually 0.01 to 10 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. It is preferably from 0.03 to 8 parts by weight, particularly preferably from 0.03 to 5 parts by weight.

The decane coupling agent which can be used in the ultraviolet curable resin composition of the present invention can be used without any particular limitation as long as it is a known decane coupling agent. In view of the fact, the durability of the cured layer of the ultraviolet curable resin composition of the present invention is improved, and therefore, the compound represented by the following formula (4) is preferably used.

(wherein R ₅ and R ₆ are each independently present, and R ₅ represents an alkyl group having 1 to 3 carbon atoms, and R ₆ represents an alkylene group having 1 to 6 carbon atoms.)

Here, the compound represented by the above formula (4) is preferably a compound of the formula (4) wherein R _{5 is} a methyl group and R ₆ is a C 2 to 4 alkylene group. Specifically, a decane compound such as 3-mercaptopropyltrimethoxydecane may be mentioned.

The content of the decane coupling agent in the ultraviolet curable resin composition of the present invention is usually 0.01 to 10 parts by weight, preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition.

The compound represented by the following formula (3) can be suitably used as an antioxidant because it can provide excellent durability to the hardened layer of the ultraviolet curable resin composition of the present invention.

(wherein R ₂ , R ₃ and R ₄ each independently exist, R ₂ represents an alkyl group having 1 to 3 carbon atoms, R ₃ represents an alkylene group having 1 to 6 carbon atoms, and R ₄ represents a carbon number of 5 to 20 alkyl.)

Preferred is a compound of the above formula (3) wherein R ₂ is a methyl group, R ₃ is an alkylene group having 2 to 5 carbon atoms, and R ₄ is a linear linear alkyl group having 10 to 15 carbon atoms.

Specific examples of the compound represented by the above formula (3) include bis[2-methyl-4-[3-(dodecylthio)propenyloxy]-5-tert-butylphenyl] sulfide, Bis[2-methyl-4-[3-(tetradecylthio)propenyloxy]-5-tert-butylphenyl]sulfide, and bis{2-methyl-4-[3 -N-alkyl (C12 or C14) thiopropyl decyloxy]-5-tert-butylphenyl} sulfide, and the like. For example, AO-23 (made by ADEKA Co., Ltd., bis{2-methyl-4-[3-N-alkyl(C12 or C14) thiopropyl decyloxy]-5-third can be purchased from the market. Butylphenyl}sulfide).

The content of the antioxidant in the ultraviolet curable resin composition is usually from 0 to 10 parts by weight based on 100 parts by weight of the total of the ultraviolet curable resin composition. It is preferably contained in a general manner from the viewpoint of durability, and is contained in an amount of from 0.01 to 10 parts by weight, preferably from 0.03 to 8 parts by weight, particularly preferably from 0.03 to 5 parts by weight.

Hereinafter, several preferred aspects of the ultraviolet curable resin composition for BD of the present invention will be described. Unless otherwise specified, the "parts" in the content of each component means the content (parts by weight) contained in 100 parts by weight of the total amount of the resin composition.

(I)

An ultraviolet curable resin composition for a Blu-ray disc comprising 5 to 15 parts of the above (A) component, 10 to 60 parts (preferably 10 to 50 parts) of the above (B) component, and 30 to 60 of the above (C) component And 2 to 8 parts of the above (D) component, and the remainder is a component other than (A) to (D).

(II)

The ultraviolet curable resin composition according to the above (I), which contains bisphenol A type di(meth)acrylate 15 which is modified by ethylene oxide 4 to 12 mol as the component (E). Up to 50 parts, more preferably 15 to 40 parts.

(III)

The ultraviolet curable resin composition according to the above (I) or (II), wherein the component (C) is an amine ester oligo which is synthesized from polytetramethylene glycol (a) and polyisocyanate (b). A polymer, an amine ester (meth) acrylate obtained by reacting a hydroxyl group of a (meth)acrylic acid C2 to C4 alkyl ester (c).

(IV)

The ultraviolet curable resin composition according to the above (III), wherein the polytetramethylene glycol (a) has a number average molecular weight of from 400 to 750.

(V)

The ultraviolet curable resin composition according to the above (III) or (IV), wherein the polyisocyanate (b) is either or both of isophorone diisocyanate and tolylene diisocyanate.

(VI)

The ultraviolet curable resin composition according to any one of the above (III) to (V), wherein the (meth)acrylic acid hydroxy C2 to C4 alkyl ester (c) is hydroxyethyl (meth)acrylate.

(VII)

The ultraviolet curable resin composition according to any one of the above (1), wherein the component (A) is dipropylene glycol di(meth)acrylate and hexanediol di(meth)acrylic acid. Either or both.

(VIII)

The ultraviolet curable resin composition according to any one of the above (1), wherein the component (B) is ethylene oxide 1 or 2 mol modified phenol (meth) acrylate.

(IX)

The ultraviolet curable resin composition according to any one of the above (1), wherein the component (D) contains at least 2,4,6-trimethylbenzimidium diphenylphosphine oxide.

(X)

The ultraviolet curable resin composition according to the above (IX), wherein the content of 2,4,6-trimethylbenzimidodiphenylphosphine oxide is from 3 to 50 with respect to the total amount of the component (D). weight%.

(XI)

The ultraviolet curable resin composition according to any one of the above (1), wherein the component (F) is contained in an amount of from 0.01 to 10 parts, preferably from 0.03 to 5 parts.

(XII)

The ultraviolet curable resin composition according to the above (XI), wherein the component (F) is a compound having a hindered piperidine skeleton containing a (meth)acryl fluorenyl group.

(XIII)

The ultraviolet curable resin composition according to any one of the above-mentioned (I), wherein the compound represented by the above formula (3) as an antioxidant is contained in an amount of 0.01 to 10 parts, preferably 0.03 to 5 parts. Share.

(XIV)

The ultraviolet curable resin composition according to any one of the above (1), wherein the compound represented by the above formula (4) as a decane coupling agent is further contained in an amount of 0.01 to 10 parts, preferably 0.05 to 3 copies.

In the ultraviolet curable resin composition of the present invention, in order to obtain adhesion of a cured product (especially adhesion to a light-reflecting layer or an interface layer), restorability, hardness, and durability are good, and ultraviolet curing is performed. A preferred embodiment of the ultraviolet curable resin composition in which the amount of bending change due to the curability and temperature change of the resin composition is small and the amount of change in bending during curing is small is as follows.

(i) The ultraviolet curable resin composition according to any one of the above (I) to (XV), which contains 5 to 15 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition as the (A) And one or both of the components of dipropylene glycol di(meth)acrylate and hexanediol di(meth)acrylate, and 12 to 50 parts by weight of the ethylene oxide 1 molybdenate as the component (B) One or both of a phenol (meth) acrylate and an ethylene oxide 2 molar modified phenol (meth) acrylate, and 30 to 50 parts by weight of the polytetramethylene as the component (C) An amine ester (meth) acrylate of a reaction of a diol (particularly a number average molecular weight of 400 to 750) with polyisocyanate (b) and 2-hydroxyethyl (meth)acrylate, and 2 to 8 parts by weight Photopolymerization initiator (D).

(i) The ultraviolet curable resin composition according to any one of the above (1), wherein the (meth)acrylic acid phenoxy group B as the component (B) is contained. The ester is 20 to 40 parts by weight.

(iii) The ultraviolet curable resin composition according to any one of the above (I) to (IV), wherein the epoxy resin as the (E) component is further contained Ethane 9 to 11 moles modified bisphenol A type di(meth) acrylate 15 to 30 parts by weight.

(iv) The ultraviolet curable resin composition according to any one of the above (I) to (iii), wherein the amine ester contained in the ultraviolet curable resin composition is a total amount of (meth) acrylate component, an amine ester of a reaction of a polytetramethylene glycol having a number average molecular weight of 400 to 750 with a polyisocyanate and 2-hydroxyethyl (meth)acrylate (methyl) The content of the acrylate (C) is 90% by weight or more (particularly preferably 100% by weight).

(v) The ultraviolet curable resin composition according to any one of the above (1) to (iv), wherein the total amount of the resin composition of the present invention is 100 parts by weight. The content of the above (A) component, (B) component and (C) component is usually 45 to 98 parts by weight, preferably 50 to 80 parts by weight, more preferably 55 to 75 parts by weight, and the remainder The ingredients are (D) ingredients and optional ingredients.

(vi) The ultraviolet curable resin composition according to any one of the above (I) to (IV), wherein, when the component (A) content is 100 parts by weight, Here, the content of the component (B) is more than 100 parts by weight and 600 parts by weight or less, and when the content of the (C) is 100 parts by weight with respect to the amine ester (meth) acrylate (C), (B) The content of the component is a ratio of about 30 to 90 parts by weight.

(vii) The ultraviolet curable resin composition according to any one of the above (1) to (vi), which contains the ethylene oxide 9 as the (E) component. To 11 moles of modified bisphenol A type di(meth) acrylate, relative to 100 parts by weight of the aforementioned amine ester (meth) acrylate (C), (E) The content of the ingredients is in the range of 35 to 90 parts by weight.

(viii) The ultraviolet curable resin composition according to any one of the above (1) to (vi), wherein the ultraviolet curable resin composition is 100 parts by weight based on the total amount of the ultraviolet curable resin composition. The total amount of the methacrylate compound contained in the ultraviolet curable resin composition is less than 10 parts by weight.

The above components can be mixed and dissolved at a normal temperature to 80 ° C to obtain an ultraviolet curable resin composition for a Blu-ray disc of the present invention. The inclusions can be removed by filtration or the like as needed.

In view of coatability, the ultraviolet curable resin composition for a Blu-ray disc of the present invention has a viscosity at 25 ° C, preferably 300 to 2000 (mPa·s), more preferably 500 to 1200 (mPa·s). By making the viscosity in this range easy to form a thick film, the production time (the operation time per one production) can be shortened.

In the ultraviolet curable resin composition for BD of the present invention, a solvent other than the above components can be used. In this case, the content of the solvent is preferably less than 10 parts by weight, more preferably less than 5 parts by weight, based on 100 parts by weight of the total amount of the ultraviolet curable resin composition, and particularly preferably no solvent is used.

In the ultraviolet curable resin composition for BD of the present invention, the elastic layer formed by irradiation with ultraviolet rays preferably has an elastic modulus at 25 ° C of 10 to 3,000 MPa, more preferably 50 to 2,000 MPa, and particularly preferably 100 to 1,000 MPa.

Further, in the formed hardened layer, since the bending due to the temperature change is small, the signal characteristic error due to the temperature change can be effectively prevented. Therefore, when the ultraviolet curable resin composition is used for the light transmissive layer of BD, it is bent at 5 to 55 ° C when stored at 25 ° C. The amount of change is preferably less than 0.8 degrees, and particularly preferably less than 0.6 degrees. In addition, the bending value is a bending value (angle) of a portion near the outer periphery of the optical disk and 56 mm from the center of the optical disk.

[BD]

The BD of the present invention is configured to form at least a light reflecting layer and a light penetrating layer on a substrate, and to record or play through the light penetrating layer by a blue laser, wherein the light penetrating layer comprises the present invention. The light-transmitting layer is a cured product of an ultraviolet curable resin composition. In the BD, the light transmissive layer may be the outermost layer on one side of the BD, or have a hard coat layer thereon and have the hard coat layer as the outermost layer. The outermost layer on the other side is usually a substrate. In the BD of the present invention, the cured layer of the ultraviolet curable resin composition for a light-transmitting layer of the present invention is used as the light-transmitting layer, so that the adhesion is less likely to occur even under high temperature and high humidity, and excellent durability can be obtained. Therefore, the information can be recorded/played well.

In the BD of the present invention, the light penetrating layer preferably has a laser light having a laser light oscillation wavelength of 370 to 430 nm and can efficiently penetrate, and preferably has a light transmittance of 850 nm of 85% or more in a thickness of 100 μm. Good is over 90%.

The light transmissive layer preferably has a thickness in the range of 50 to 150 μm, more preferably 75 to 150 μm. When the light penetrating layer is a single layer, the thickness is set to about 100 μm. The thickness of the light transmissive layer will have a great influence on the light transmittance, signal reading and recording, and must be fully managed. The light transmissive layer may be formed of a single layer of the hardened layer of the thickness, or a plurality of layers of the light transmissive layer may be laminated. In the case of a plurality of layers, the sum of the thicknesses of the respective light transmissive layers is preferably in the above thickness range. The light transmissive layer of the present invention is generally preferably a single layer.

The BD of the present invention usually has a light reflecting layer. The light-reflecting layer may be a BD which can reflect laser light and can be recorded/played. For example, a metal such as gold, silver, copper or aluminum, or an alloy containing any of them or an inorganic compound such as ruthenium may be used. Among them, since light reflectance is high in the vicinity of 400 nm, it is preferable to use silver or an alloy containing silver as a main component. The thickness of the light reflecting layer of the BD of the present invention is preferably about 10 to 60 nm.

The light reflecting layer is usually formed on the substrate by vapor deposition or sputtering of the aforementioned metal or an alloy thereof.

By using the ultraviolet curable resin composition of the present invention, durability and adhesion of the light reflecting layer such as light resistance and heat resistance can be improved. The ultraviolet curable resin composition of the present invention is particularly suitably used for a reflective film comprising silver or an alloy containing silver as a main component.

As the BD substrate of the present invention, a circular resin substrate having a disk shape can be used, and polycarbonate is preferably used. When the BD is dedicated for playback, the pits serving as recording information are formed on the surface of one surface of the substrate, that is, on the surface of the laminated light-reflecting layer, and a reflective film is formed thereon to form a recording layer.

When the BD of the present invention is a writable BD, a recording layer is provided between the light reflecting layer and the light transmissive layer. The recording layer may be any one of a phase change type recording layer, a magneto-optical recording layer, or an organic dye type recording layer as long as information can be recorded/played.

The writable BD is provided with a recording layer on the recording information surface of the substrate. As the recording layer, a conventionally known material can be suitably used as the recording layer for an optical recording medium. For example, a dye, an amorphous semiconductor, a partial nitride film, a partial oxide film (inorganic film), or the like can be given.

The BD of the present invention may have a plurality of layers of the above recording layer. At this time, each layer may be formed of the same material or may be formed by arbitrarily combining other materials. By using other materials and forming a plurality of recording layers, optical properties such as individual transmittances of the respective layers can be changed.

Specific examples of the recording layer include an inorganic recording layer and an organic dye type recording layer. Examples of the material used for the inorganic recording layer include an amorphous semiconductor material, a partial nitride, and a partial oxide.

Examples of the amorphous semiconductor material used in the inorganic recording layer include materials such as SbTe, GeTe, GeSbTe, InSbTe, AgSbTe, AgInSbTe, GeSb, GeSbSn, InGeSbTe, and InGeSbSnTe. In the amorphous semiconductor material, in order to increase the crystallization rate, it is preferred to use a composition containing Sb as a main component. In addition, these amorphous semiconductor materials may be used singly or in combination of two or more kinds in any combination and in any ratio.

Specific examples of the partial nitride film and the partial oxide film used as the inorganic recording layer include a partial nitride film containing BiGeN or SnNbN, and a partial oxide film containing TeOx, BiFOx, and TiSixOy.

An organic dye type recording layer can be used as the recording layer. The material of the organic dye type recording layer must have sensitivity to the wavelength of the laser light used for recording and playback. Further, the material of the organic dye type recording layer must be physically or chemically reacted by irradiation of laser light, thereby changing the refractive index. Examples of the material of the organic dye type recording layer include a cyanine dye, an oxonol dye, an azo dye, a phthalocyanine dye, and a porphyrin dye. Use these organic materials and examples A solution in which a solvent such as cellosolve acetate or tetrafluoropropane is mixed is applied to the solution to form an organic dye-type recording layer by a spin coating method or the like. The film thickness of the organic dye type recording layer is preferably 15 nm or more and 25 nm or less.

In the BD of the present invention, an interface layer can be formed on the recording layer. The interface layer has the function of buffering the heat generated by the recording layer and adjusting the reflectivity of the optical disc. Further, the interface layer has a function of preventing diffusion of the recording material contained in the recording layer to the light-transmitting layer when the light-transmitting layer is formed, or preventing the solvent or the like contained in the resin composition for the light-transmitting layer from being impregnated into the recording layer or the like. The function of the phenomenon.

The material constituting the interface layer is usually a mixture of cerium oxide and zinc sulfate. Other examples include oxides of cerium oxide (especially cerium oxide), zinc oxide, cerium oxide, cerium oxide, indium oxide, indium tin oxide, potassium oxide, and aluminum oxide; sulfides such as zinc sulfide and barium sulfide; and nitriding; Niobium and the like; niobium carbide; a mixture of the above oxides and sulfur; a fluoride such as magnesium or calcium. The interface layer can be formed by a method such as sputtering.

The hardened film containing the ultraviolet curable resin composition of the present invention is excellent in adhesion to a material forming the interface layer, specifically, a mixture of ceria and zinc sulfide, indium oxide or indium tin oxide, and thus is suitable. .

The BD of the present invention can form two or more recording layers (information recording sites). For example, when playing a dedicated BD, the first light reflecting layer and the first light penetrating layer may be laminated on the substrate having the dimples, and when the other layers are laminated on the first light penetrating layer or as needed Then, on the other layer, a second light anti-side layer and a second light transmissive layer are formed. At this time, pits are formed on the first light transmissive layer or on other layers laminated on the light transmissive layer. In addition, When the BD is recorded/played, the first light reflecting layer, the first recording layer and the first light penetrating layer may be laminated on the substrate, and the second reflecting layer and the second record may be formed on the first light penetrating layer. The layer and the second light transmissive layer are composed of two recording layers. Alternatively, it may be a composition of a recording layer having a layer of three or more layers. When a plurality of layers are laminated, the total thickness of each layer may be appropriately adjusted so as to have the above thickness. Further, an interface layer may be interposed between the light reflecting layer and the recording layer, and/or between the recording layer and the light penetrating layer.

When the ultraviolet curable resin composition of the present invention is used for a light transmissive layer, the ultraviolet curable resin composition of the present invention can also be suppressed from corrosion and deterioration of the interface layer or the recording layer contacting the light transmissive layer. It is suitably used for a BD having a recording layer.

In the BD of the present invention, the light transmissive layer may be the outermost layer, but a surface coating (hard coat layer) may be provided on the surface layer. The material for forming the hard coat layer is not particularly limited as long as it can form a cured layer having high hardness and excellent wear resistance, and an ultraviolet curable resin composition is usually used.

The BD of the present invention is a dedicated disc for playing and a disc that can be recorded/played.

A dedicated optical disc can be manufactured by the following method. A circular resin substrate is provided with a pit of the information recording layer at the time of injection molding, and then a light reflection layer is formed on the information recording layer. After the other layers are laminated on the light-reflecting layer as necessary, the light-transmitting layer of the present invention is coated with an ultraviolet-curable resin composition by, for example, a 2P method, a roll coating method, a screen printing method, a spin coating method, or the like. . The BD for the present invention is obtained by irradiating ultraviolet rays of the active energy ray on one side or both sides of the BD to near ultraviolet rays (near the wavelength of 200 to 400 nm) to cure the resin composition to form a light transmissive layer.

A recordable/playable optical disc can be manufactured by the following method. A light reflection layer is formed on one circular resin substrate by vapor deposition, sputtering, or the like, and a recording layer is provided thereon. The recording layer is laminated on the recording layer or the interface layer as necessary, and the ultraviolet curable resin composition for a light-transmitting layer of the present invention is applied by the above method or the like. The BD is irradiated with an active energy ray in the same manner as described above to harden the resin composition to form a light transmissive layer, thereby obtaining the recordable/playable BD of the present invention.

The ultraviolet light source which is used to cure the light-transmitting layer ultraviolet curable resin composition is not particularly limited as long as it can be irradiated with ultraviolet rays to near ultraviolet rays (having a wavelength of around 200 to 400 nm). For example, a (pulsed) xenon lamp, an electrodeless lamp, a metal halide lamp, a low pressure or high pressure mercury lamp, or an ultra high pressure mercury lamp can be used. Ultraviolet irradiation can be carried out by continuous light irradiation or by flash irradiation.

When the ultraviolet ray is irradiated, it is preferably controlled so that the cumulative amount of light is 0.05 to 1 J/cm ² . More preferably, the cumulative amount of light is 0.05 to 0.8 J/cm ² , particularly preferably 0.05 to 0.6 J/cm ² .

The ultraviolet curable resin composition for a light-transmitting layer used in the BD of the present invention is excellent in curability, and is sufficiently hardened even when the amount of accumulated light is small, and does not cause stickiness on the end faces and surfaces of the BD, and is not The BD is bent and skewed.

[Implementation]

Hereinafter, as a specific example of the BD of the present invention, an example of a specific configuration of a single-layer type BD and a multi-layer type BD (for example, a two-layer type BD) is as follows.

In the BD of the present invention, a single layer type BD is preferably implemented, for example, The following composition: a light reflecting layer and a light penetrating layer are laminated on the substrate, and a blue laser is incident on the light penetrating layer side to perform information recording or playing, or a hard coat layer is disposed on the light penetrating layer. Composition. The light-transmitting layer is a layer containing a cured product of the ultraviolet curable resin composition of the present invention, and has a thickness of, for example, 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 from 1 to 10 μm, more preferably from 3 to 5 μm. The thickness of the substrate is about 1.1 mm. The light reflecting layer is preferably a film of silver or an alloy containing silver as a main component.

Further, a preferred embodiment of the single-layer type BD having a recording layer is, for example, a light-reflecting layer on a substrate, a first interface layer and a recording layer (inorganic recording layer, organic dye type recording) which are required to be provided. The layers may be layered, the second interface layer, and the light transmissive layer are sequentially layered, and the blue light is incident on the light penetrating layer side for information recording or playback, or the hard coating layer is provided on the light penetrating layer. The composition of the layers.

In a preferred embodiment of the multi-layer type BD, for example, a first light-reflecting layer and a first light-transmitting layer are laminated on a substrate, and a second light-reflecting layer and a second light-transmitting layer are laminated thereon, and The second light-transmitting layer side is formed by a two-layer type BD in which a blue laser is incident and information recording or playback is performed. The first light-transmitting layer and the second light-transmitting layer are layers containing a cured product of the ultraviolet curable resin composition, and at least one of the layers is a layer containing the ultraviolet curable resin composition of the present invention. The thickness of the layer is preferably such that the thickness of the first light-transmitting layer and the thickness of the second light-transmitting layer are in the range of 100 ± 10 μm. The thickness of the substrate is about 1.1 mm. The light reflecting layer is a film of silver or an alloy containing silver as a main component.

Further, in a preferred embodiment of the multilayer BD having a recording layer, for example, the first light reflecting layer, the first interface layer, and the first recording layer (inorganic recording layer and organic dye type recording layer) are formed on the substrate. The second interface layer and the first light transmission layer may be laminated in this order, and the second light reflection layer, the third interface layer, and the second recording layer (both inorganic and organic pigment types) may be laminated thereon, and the fourth layer may be formed. The interface layer and the second light transmissive layer are composed of a two-layer type BD in which a blue laser is incident on the second light transmissive layer side for information recording or playback.

In the two-layer type BD having such a configuration, since the recording track (groove) is also formed on the surface of the first light-transmitting layer, the layer can be laminated on the layer including the cured film of the ultraviolet curable resin composition excellent in adhesion. It is suitable to form a cured film of the ultraviolet curable resin composition of the recording track, and the first light penetrating layer is formed in a plurality of layers. Further, in this configuration, a hard coat layer may be provided on the outermost layer.

(Example)

Hereinafter, the present invention will be specifically described by way of examples, but the invention is not limited to the examples.

The ultraviolet curable resin composition containing the composition shown in the following Table 1 was prepared as Examples 1 to 7 and Comparative Examples 1 to 3.

Using the obtained ultraviolet curable resin composition, a Blu-ray disc having an inorganic recording layer was produced by the following method, and the characteristics were evaluated.

(production of Blu-ray discs)

1. A silver alloy was sputtered on a polycarbonate substrate having a diameter of 12 cm and a thickness of 1.1 mm having a guide groove of 0.32 μm in a track pit, and a reflective layer was formed by sputtering a silver alloy so as to have a film thickness of 100 nm. Thereafter, TiSiO is sputtered to form an inorganic recording layer on the reflective layer. Further, a ZnS-SiO ₂ (mole ratio 80:20) was sputtered so as to have a thickness of about 15 nm, whereby an interface layer was formed to fabricate a Blu-ray disc substrate.

2. The resulting Blu-ray disc substrate is carried on the rotating table with the interface layer facing up. A circular capping treatment was carried out so as to cover an inner diameter of 11.5 mm, and then 3.0 g of the ultraviolet curable resin composition of the present invention or comparatively was supplied to the cap of the center portion.

3. Spin coating at a speed of 900 rpm for 4 seconds to 7 seconds, and coating at a coating film thickness of 95 μm. At the end of the spin coating, two shots were irradiated with a xenon flash lamp and hardened to the extent that there was no surface fluidity.

4. A high-pressure mercury lamp was used, and ultraviolet rays were irradiated from the upper side for 3 seconds so that the cumulative light amount was 400 mJ/cm ² , and the coating film of the ultraviolet curable resin composition was completely cured.

5. The optical disk substrate is carried on the rotary table with the hardened ultraviolet curable resin composition facing upward. The coating treatment was carried out in a circular shape so as to cover the inner diameter of 11.5 mm, and then 3.0 g of the ultraviolet curable resin composition (HOD 3950B, manufactured by Nippon Kayaku Co., Ltd.) for the hard coat layer was supplied to the cap of the center portion. .

6. Spin coating at a speed range of 6000 rpm for 4 seconds to 7 seconds. At the end of the spin coating, two shots were irradiated with a xenon flash lamp and hardened to the extent that no surface fluidity was observed, and a Blu-ray disc of the present invention or a comparative use was produced.

The physical properties of the obtained Blu-ray discs were evaluated to obtain the results of Table 1 below.

In addition, each component shown by the abbreviation in the table is as follows.

UA-1: an amine ester acrylate obtained by reacting polytetramethylene glycol (number average molecular weight: 650), toluene diisocyanate, and hydroxyethyl acrylate in a molar ratio of 1:2:2.

UA-2: an amine ester acrylate obtained by reacting polytetramethylene glycol (number average molecular weight 650), isophorone diisocyanate, and hydroxyethyl acrylate in a molar ratio of 1:2:2.

UA-3: an amine ester acrylate obtained by reacting polypropylene glycol (number average molecular weight: 1000), toluene diisocyanate, and hydroxyethyl acrylate in a molar ratio of 1:2:2.

Photomer 4226: Dipropylene glycol diacrylate, manufactured by Cognis Co., Ltd.

Photomer 4017: 1,6-hexanediol diacrylate, manufactured by Cognis Co., Ltd.

TPGDA: tripropylene glycol diacrylate, manufactured by Daicel-cytec Co., Ltd.

BPE4A: Ethylene oxide 4 molar modified bisphenol A diacrylate, First Industrial Pharmaceutical Co., Ltd.

BPE-10: Ethylene oxide 10 molar modified bisphenol A type diacrylate, First Industrial Pharmaceutical Co., Ltd.

Photomer 4035: phenoxyethyl acrylate, manufactured by Cognis Co., Ltd.

EBECRYL110: Ethylene oxide 2 molar modified phenol acrylate, manufactured by Daicel-cytec Co., Ltd.

FA-512A: Dicyclopentadienyloxyethyl acrylate, manufactured by Hitachi Chemical Co., Ltd.

IRGACURE 184: 1-hydroxycyclohexyl phenyl ketone, manufactured by BASF Corporation.

SPEEDCURE TPO: 2,4,6-trimethylbenzimidium diphenylphosphine oxide, manufactured by DKSH JAPAN Co., Ltd.

LA-82: 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, manufactured by ADEKA CORPORATION.

Z-6062: 3-mercaptopropyltrimethoxydecane, manufactured by Toray Dow Corning Co., Ltd.

AO-23: bis{2-methyl-4-[3-N-alkyl(C12 or C14)thiopropenyloxy]-5-tert-butylphenyl} sulfide, ADEKA GmbH system.

(adhesion test)

The peeling strength was measured using a tensile tester (RTM-250, manufactured by Toyo Baldwin Co., Ltd.), whereby the adhesion test was performed. In the measurement, the cured film having the ultraviolet curable resin composition of each of the obtained examples or the comparative examples was used, and the surface of the hardened film side of the BD was cut to a width of 10 mm, and the end portion of the cured film having a width of 10 mm was peeled off from the interface layer by a blade. Then, the hardened film was peeled off in a 90-degree direction by a tensile tester and peel strength (25 ° C, 45% RH) was measured.

Evaluation of adhesion:

◎...measured value is 0.4g/10mm or more

○...The measured value is 0.2 g/10 mm or more and less than 0.4 g/10 mm.

×...The measured value is less than 0.2g/10mm

(recovery test)

The restorability test was performed using a Fisher hardness tester (HP100-XYp, manufactured by Fischer Instruments). The measurement method was performed by pressurizing at 1000 mN for 60 seconds, and then measuring the depression (25 ° C, 45% RH) of the cured film formed after removing the pressurization (0 mN) for 60 seconds.

Restoration assessment:

◎...The final measured value is less than 4mm

○...The final measured value is 4mm or more and less than 5mm.

△... The final measured value is 5mm or more and less than 6mm.

×...The final measured value is 6mm or more.

(initial bending test)

The initial bending was evaluated by measuring the bending of the substrate before coating the ultraviolet curable resin composition of the examples or the comparative examples and the bending of the substrate after the resin composition was applied and cured. The bending of the BD substrate was measured by using a mechanical property measuring device (manufactured by Dr. Schenk Co., Ltd., product name: Prometheus MT-146) of BD to measure the angle of the portion close to the outermost periphery of the optical disk and 56 mm from the center of the optical disk.

Initial bending change amount = bending value after hardening - bending value of the substrate before coating the ultraviolet curable resin composition

◎... less than ±0.4 degrees

○...±0.4 degrees or more, less than ±0.6 degrees

×...±0.6 degrees or more

(temperature bending test)

The bending of the BD substrate which is cured by curing the ultraviolet curable resin composition of the coating example or the comparative example, and the substrate at a low temperature (5 ° C) or high temperature (50) °C) The difference in bending of the substrate placed for 24 hours was used to evaluate the temperature bending. The measurement of the bending of the BD substrate was carried out in the same manner as described above.

Temperature bending change amount = bending value after standing at low temperature or high temperature for 24 hours - bending value of the substrate after hardening

◎... less than ±0.6 degrees

○...±0.6 degrees or more, less than ±0.8 degrees

×...±0.8 degrees or more

(Recording signal characteristics and visual judgment after durability test of Blu-ray disc)

The BDs of PULSTEC Co., Ltd. of the respective embodiments or the comparative examples were used, and the linear velocity of 4.92 m/s, the playback power of 0.30 mW, the recording power of 6.0 mW, and the T continuous recording (1 T long = 0.08) were used. After recording, it was placed in an environment of 80 ° C and 85% RH for 250 hours.

For the Blu-ray Disc after the durability test, the recording signal characteristics (jitter, R8H, and RSER) were measured using the above-described signal measuring device, and evaluated based on the following criteria. Further, the surface of the Blu-ray disc after the durability test was observed and visually judged (appearance evaluation), and evaluated based on the following criteria. The jitter value, R8H and RSER are one of the electrical signals of the BD.

(a) jitter value

The higher the jitter value indicates that the signal data of the Blu-ray disc is degraded, and if it is 10% or more, it is difficult to read the written data.

Evaluation of jitter values:

○...the jitter value is less than 10.0%

×... jitter value is 10.0% or more

(b) R8H

The lower the value of R8H (reflectance), the worse the data of the Blu-ray disc.

Evaluation of R8H:

○...10 or more

×... less than 10

(c) RSER

The higher the value of RSER, the worse the data of BD is.

RSER evaluation:

○...Unfilled 2×10 ^-3

×...2×10 ^-3 or more

(d) visual judgment

The cured film of the Blu-ray disc was visually observed, and it was judged whether there was white turbidity or shark skin-like hardening unevenness.

Visual assessment:

○...The hardened film has no white turbid or shark skin-like hardening unevenness

×...The hardened film has white turbidity or shark skin-like hardening unevenness

(Comprehensive Evaluation)

In the comprehensive evaluation, recorded signal characteristics (jitter value, R8H, RSER), and visual observation after adhesion (90° peel test), restorability, initial bending, temperature bending (5 ° C and 50 ° C), durability test In the evaluation of individual evaluations, when all the evaluations are ◎ or ○, the comprehensive evaluation is ○, and when any item is △ or ×, the comprehensive evaluation is ×.

From the results of Table 1, the BD having the cured product of the resin composition of the present invention of Examples 1 to 7 as a light-transmitting layer had good recording signal characteristics after the durability test. Further, the trees of the present invention of Examples 1 to 7 The fat composition is excellent in hardenability, and the cured product is excellent in adhesion and resilience. It has been confirmed that the cured product can be used as a light-transmitting layer to obtain bending during curing and temperature change. BD with very little change.

Further, in the durability test of the BDs of Examples 4 to 7, even when placed in an environment of 80 ° C and 85% RH for 500 hours, the jitter value was less than 10.0%, and the durability was excellent.

Claims (16)

A blue light disc having a cured layer of the ultraviolet curable resin composition as a light transmissive layer on a substrate, and an ultraviolet curable resin composition is an ultraviolet curable resin composition for a Blu-ray disc, wherein the ultraviolet curable resin is used. The following components (A) to (D) are contained in 100 parts by weight of the total amount of the composition, and (A) 5 to 15 parts by weight of the compound represented by the following formula (1) (wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group; (B) 10 to 60 parts by weight of the compound represented by the following formula (2) (wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10); (C) a reaction of polytetramethylene glycol, polyisocyanate, and a C2 to C4 alkyl (meth)acrylate 30 to 60 parts by weight of the amine ester (meth) acrylate; and (2) 2 to 8 parts by weight of the photopolymerization initiator. The Blu-ray disc of claim 1, wherein at least a light reflecting layer and a light penetrating layer are formed on the substrate, and a blue laser having a vibration wavelength in a range of 370 nm to 430 nm passes through the light passing through. Record or play through the layer. An ultraviolet curable resin composition for a Blu-ray disc, which comprises the following components (A) to (D) in a ratio of 100 parts by weight based on the total amount of the ultraviolet curable resin composition, (A) the following formula (1) 5 to 15 parts by weight of the compound represented (wherein R ₁ represents a linear alkyl group having 4 to 10 carbon atoms; an alkyl group having an ether bond of 4 to 10 carbon atoms; or an alkyl group having a branched chain having 4 to 10 carbon atoms; R ₁₁ represents a hydrogen atom or a methyl group; (B) 10 to 60 parts by weight of the compound represented by the following formula (2) (wherein R ₂₁ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10); (C) a reaction of polytetramethylene glycol, polyisocyanate, and a C2 to C4 alkyl (meth)acrylate 30 to 60 parts by weight of the amine ester (meth) acrylate; and (2) 2 to 8 parts by weight of the photopolymerization initiator. The ultraviolet curable resin composition for a Blu-ray disc according to the above aspect of the invention, wherein the compound (A) represented by the above formula (1) is dipropylene glycol di(meth)acrylate and hexanediol di ( Either or both of methyl acrylate. The ultraviolet curable resin composition for a Blu-ray disc according to claim 3, wherein the polytetramethylene glycol, the polyisocyanate, and the amine of the reactant of the (meth)acrylic acid hydroxy C2 to C4 alkyl ester are used. In the ester (meth) acrylate (C), the number average molecular weight of the polytetramethylene glycol used in the reaction is from 400 to 750. The ultraviolet curable resin composition for a Blu-ray disc according to the third aspect of the invention, wherein the (E) is contained in an amount of 15 to 53 parts by weight based on 100 parts by weight of the total amount of the ultraviolet curable resin composition. 4 to 12 moles of ethylene oxide modified bisphenol A type di(meth)acrylate. The ultraviolet curable resin composition for a Blu-ray disc according to any one of claims 3 to 6, which contains a compound represented by the following formula (3) as an antioxidant. Wherein R ₂ , R ₃ and R ₄ are each independently present, R ₂ represents an alkyl group having 1 to 3 carbon atoms, R ₃ represents an alkylene group having 1 to 6 carbon atoms, and R ₄ represents a carbon number of 5 to 20 alkyl). The ultraviolet curable resin composition for a Blu-ray disc according to any one of claims 3 to 6, which contains a compound represented by the following formula (4) as a decane coupling agent. (wherein R ₅ and R ₆ are each independently present, R ₅ represents an alkyl group having 1 to 3 carbon atoms, and R ₆ represents an alkylene group having 1 to 6 carbon atoms). The ultraviolet curable resin composition for a Blu-ray disc according to any one of claims 3 to 6, which contains (F) a compound having a hindered piperidine skeleton. The ultraviolet curable resin composition for a Blu-ray disc according to claim 9, wherein the compound (F) having a hindered piperidine skeleton is a compound having both a hindered piperidine skeleton and a (meth)acrylonium group. The ultraviolet curable resin composition for a Blu-ray disc according to any one of claims 3 to 6, wherein at least 2,4,6-trimethylbenzimidium diphenylphosphine oxide is used as photopolymerization Starting agent (D). The ultraviolet curable resin composition for a Blu-ray disc according to claim 6, which comprises a compound selected from the group consisting of a compound having a hindered piperidine skeleton (F), a decane coupling agent represented by the above formula (4), and the above formula. (3) At least one of the groups of antioxidants indicated. The ultraviolet curable resin composition for a Blu-ray disc according to claim 6, wherein the bisphenol A type di(meth)acrylate modified with at least 9 to 11 mol of ethylene oxide is used as (E) The component is contained in an amount of 35 to 90 parts by weight based on 100 parts by weight of the component (C). The use of the ultraviolet curable resin composition according to any one of claims 3 to 13, which is a light transmissive layer for forming a Blu-ray disc having a recording layer. A cured product obtained by irradiating an active energy ray to an ultraviolet curable resin composition according to any one of claims 3 to 13. A method for producing a Blu-ray disc having a recording layer, which is applied to a Blu-ray disc substrate by applying the ultraviolet curable resin composition according to any one of claims 3 to 13 and coated by irradiating an active energy ray The film is hardened to form a light penetrating layer.