WO2006016538A1

WO2006016538A1 - Optical disk

Info

Publication number: WO2006016538A1
Application number: PCT/JP2005/014451
Authority: WO
Inventors: Daisuke Ito; Hirokazu Saito; Takeshi Isonaka
Original assignee: Dainippon Ink And Chemicals, Inc.
Priority date: 2004-08-09
Filing date: 2005-08-05
Publication date: 2006-02-16
Also published as: TW200613483A

Abstract

Disclosed is an optical disk having a structure wherein a dye recording layer (a1), a semi-transparent light-reflecting layer (t1), a cured resin layer (c1) of an ultraviolet-curable composition, a dye recording layer (b) and a light-reflecting layer (r) are arranged in layers in this order. The ultraviolet-curable composition contains (i) a compound A having a radically polymerizable unsaturated double bond and a polycyclic structure in a same molecule, and (ii) a compound B having a radically polymerizable unsaturated double bond and a trivalent partial structure represented by the formula (I) below in a same molecule.

Description

Optical disc

Technical field

[0001] The present invention relates to an optical disc having a structure provided with a plurality of recording layers.

Background art

[0002] A typical example of a shell-and-shell optical disc is a DVD (digital versatile disc or digital video disc). This DVD has a single optical disk substrate having a recording layer and an optical disk substrate having no recording of information, or two disk substrates having a recording layer, in the middle. It is joined through a resin layer.

[0003] DVDs can be broadly classified into read-only types and recordable types, and recordable DVDs are called write-once DVD—R and DVD + R, and rewritable DVD-RW and DVD + RW. , DVD —There is a method called RAM. Among these DVDs, write-once DVD-R and DVD + R DVDs are characterized by the use of organic dyes in the recording layer, unlike other DVDs. In a write once optical disc, a recording layer is formed on a transparent substrate by irreversibly changing optical characteristics or forming a concavo-convex shape by laser light irradiation. As the recording layer, for example, cyanine-based, phthalocyanine-based, azo-based organic dyes that decompose when heated by laser light irradiation, change their optical constants, and cause deformation of the substrate due to volume change are used. It is done.

[0004] Conventionally, a write-once DVD is obtained by bonding an optical disk substrate in which a recording layer made of an organic dye and a light reflecting layer are stacked on a substrate, and an optical disk substrate having no information recording layer. One optical disc was provided with one recording layer. In order to increase the recording capacity of an optical disk, an optical disk in which multiple recording layers are provided on one optical disk has been proposed. (For example, Patent Document 1) That is, it is formed of a light recording layer of a first optical recording surface formed from a dye recording layer and a light reflecting layer provided on a substrate, and another dye recording layer and a light reflecting layer. A multilayer optical disc is shown in which a dye recording layer on the second optical recording surface is bonded with a light-transmitting intermediate layer interposed therebetween. According to the optical disk described in this document, laser light is irradiated from one side and the second optical recording is performed through the recording layer on the first optical recording surface and further through the intermediate layer. It is possible to record and reproduce the recording layer of the surface. In addition, a method for manufacturing a multilayer write-once optical disc has been proposed in which the intermediate layer that joins the first optical recording surface and the second optical recording surface has a structure in which a plurality of resin layers are laminated. (For example, Patent Document 2) In these multilayer write-once optical discs, signals are recorded by irradiating organic dyes or the like with laser light as described above. In this case, the organic dye or the like is locally heated and becomes a high temperature to cause a chemical change. At the same time, the peripheral portion including the intermediate layer is also heated. When this intermediate layer is formed of a cured layer of an ultraviolet curable composition, the composition is designed so that the cured layer is not deformed by local heating during laser writing and does not interfere with reading of the recorded signal. There is a need to do. In the conventional write-once DVD with one recording layer, such a problem does not occur because the recording layer is provided on the polycarbonate substrate.

[0005] By the way, a technique relating to an active energy ray-curable composition for optical discs in which an isocyanurate compound and a compound having a cyclic skeleton are used in combination is known (for example, see Patent Document 3). This technique relates to an active energy ray-curable composition for optical discs that can form a cured product layer having a low water absorption rate and excellent transparency with a low cure shrinkage during polymerization. A composition containing 10% by mass of (2-atalyloxyxetyl) isocyanurate and 10% by mass of tricyclodecane dimethanol diatalylate is also described. However, this patent document describes a reproduction-only optical disc, particularly a protective layer having a thickness of about 100 microns. Only a blue-ray optical disc and a composition for forming the protective layer are described, and matters relating to a multilayer write-once optical disc, particularly a multilayer write-once optical disc. No mention is made of the fact that the intermediate layer of the core is partially deformed by heating during signal writing with laser light, and as a result, PI error and jitter are increased during signal reading. However, there is no description about the behavior of the composition described in the above in heating, and there is no description suggesting them, so that the composition described in the patent document is used in the middle of a multilayer write-once optical disc. The effectiveness of using it as a layer composition was not entirely predictable.

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2003-331463 Patent Document 2: JP 2003-77191 A

Patent Document 3: Japanese Patent Laid-Open No. 2003-119231

Disclosure of the invention

Problems to be solved by the invention

Therefore, an object of the present invention is to be used between a translucent reflective layer and a dye recording layer of a multilayer write-once optical disc, and deformation occurs even when heated by laser light during signal writing. Therefore, it is intended to provide a multi-layer write-once optical disc having a good recording property, which is provided with a cured resin layer of an ultraviolet curable composition that does not cause a signal reading error.

Means for solving the problem

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have completed the present invention. That is, the present invention provides a dye recording layer (a)

1, a translucent light reflecting layer (t), a cured resin layer (c) of an ultraviolet curable composition, a dye recording layer (b), and a light reflecting layer

1 1

Layer (r) has a structure laminated in this order,

The ultraviolet curable composition is

ω Compound A with radically polymerizable unsaturated double bond and polycyclic structure in the same molecule

,as well as

(ii) radically polymerizable unsaturated double bond in the same molecule and formula (I)

[Chemical 1]

The present invention provides an optical disc characterized by being a composition containing Compound B having a trivalent partial structure represented by the formula:

[0009] The cured resin layer of the ultraviolet curable composition used in the optical disk of the present invention is presumed to act on the signal characteristics of the optical recording surface as follows. Signals are applied to the optical recording surface with laser light. During recording, the dye recording layer is irradiated with a laser beam to change the dye at high temperature. At this time, the resin layer in contact with the dye recording layer on the optical recording surface also receives heat due to the chemical change of the laser and the dye, but the cured resin layer made of the ultraviolet curable composition used in the optical disk of the present invention. Contains the compound A and the compound B, so that a high glass transition temperature is obtained, and the force also has a ring structure in the molecule. Even if it receives, it hardly deforms. Therefore, the group formed in the resin layer is not deformed, the signal mark is sharp, and excellent signal characteristics can be obtained.

The invention's effect

[0010] The optical disk of the present invention uses a cured resin layer made of an ultraviolet curable composition containing the compound A and the compound B between the translucent reflective layer and the dye recording layer. Even when heated by laser light at the time of writing, the cured resin layer hardly deforms. Therefore, it is possible to obtain a multi-layer write-once optical disc with good recording characteristics that does not cause a signal reading error.

Brief Description of Drawings

FIG. 1 is a diagram showing an example of an optical disc according to the present invention.

FIG. 2 is a diagram showing an example of an optical disk according to the present invention.

FIG. 3 is a diagram showing an example of an optical disc of the present invention.

Explanation of symbols

[0012] 1 substrate (d)

1

2 Dye recording layer (a)

1

3 Translucent light reflection layer (t)

1

4 Cured resin layer of UV curable composition (c)

1

5 Dye recording layer (b)

6 Light reflecting layer (r)

7 Board (d)

2

8 Adhesive layer

11 Convex recording track (group) 12 Convex recording track (group)

13 Convex recording track (group)

21 First recording layer in which a dye recording layer (a) 2 and a translucent light reflecting layer (t) 3 are laminated

1 1

22 Second recording layer in which the dye recording layer (b) 5 and the light reflecting layer (r) 6 are laminated

23 Laminate (s)

31 Dye recording layer (a)

2

32 Translucent light reflection layer (t)

2

33 Cured resin layer of UV curable composition (c)

2

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The compound A having a radically polymerizable unsaturated double bond and a polycyclic structure in the same molecule contained in the ultraviolet curable composition used in the optical disk of the present invention is a polycyclic structure in the molecule. Provides high rigidity, withstands high temperatures during laser recording, prevents deformation of the resin layer, and provides excellent long-term reliability of the dye recording layer by providing excellent heat and heat resistance to the resin layer. It is. In this specification, (meth) acrylic acid means acrylic acid or methacrylic acid, and the same applies to derivatives of acrylic acid or methacrylic acid.

[0014] As the compound A, compounds having various structures can be used. For example, a compound represented by the formula (XI), a compound having a structure in which the bisphenol A structure moiety in the formula (XI) is replaced with a hydrogenated bisphenol A structure, isobornyl (meth) acrylate, (meth) aryl Norbornyl acid, 2- (meth) ataryloxymethyl-2-methylbicycloheptane, adamantyl (meth) acrylate, dicyclopentane (meth) acrylate, dicyclopentanyl (meth) acrylate, (meth) Examples thereof include tetracyclododecanyl acrylate.

[0015] [Chemical 2]

(In the formula, R and R may be the same or different ethylene group or propylene group. Z and Z represent the same or different hydrogen atom or methyl group, m

1 2

And n may be the same or different and each represents an integer of 1 to 9, and m + n represents an integer of 2 to 10. )

Among compounds A, a structure having two or more radically polymerizable unsaturated double bonds is preferable, and a more preferable structure is a compound represented by the following formula (II).

X ¹ -R ¹ -O-R ² -O-R ³ -X ¹ (II)

(Where X ¹ is the formula (III)

[0016] [Chemical 3]

z

¾c ^

0

(Wherein Z represents a hydrogen atom or a methyl group), R ¹ and R ³ are — (〇CH 2) − (where n represents an integer of 1 to 4, m Represents 1 or 2, and the oxygen atom in the formula is linked to X ^1.

2n m

Match. R ² is a group represented by formula (IV),

[0017] [Chemical 4]

Formula (V)

[0018] [Chemical 5]

Or formula (VI)

[0019] [Chemical 6]

It is a divalent group represented by )

[0020] Specific examples of the compound represented by the formula (II) include norbornane dimethanol diatalate, norbornane diethanol di (meth) acrylate, norbornane dimethanol and 2 moles of ethylene oxide or propylene oxide. Di (meth) atalylate, tricyclodecane dimethanol di (meth) acrylate, tricyclodecane ethanol di (meth) acrylate, tricyclodecane dimethanol, ethylene oxide or pro Diol (dimethalate), pentacyclopentadecane dimethanol di (meth) atalylate, pentacyclopentadecane diethanol di (meth) atalylate, pentacyclopentadecane dimethanol obtained by adding 2 moles of pyrene oxide Ethylene oxide or Di (meth) acrylate of diol obtained by adding 2 mol of propylene oxide, di (meth) acrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to pentadecane didecane diethanol and dimethylol di There are cyclopentanedi (meth) talates, among which tricyclodecanedimethanoldi (meth) talate and pentacyclopentadecanedimethanoldi (meth) acrylate are preferred. Atarirate is especially preferred.

[0021] In the same molecule used in the present invention, a radical polymerizable unsaturated double bond and formula (I)

[0022] [Chemical 7]

As the compound B having a trivalent partial structure represented by general formula (II), compounds having various structures can be used. Among them, it is preferable to use a compound represented by the formula (VII).

(Wherein x ¹ is a group represented by the formula (III), X ² is a hydrogen atom or a group represented by the formula (III), and R ¹ is-(OC H)-(formula In which n represents an integer of 1 to 4, m represents 1 or 2, and the formula n 2n m

The oxygen atom inside binds to X ¹ or X ² . ). )

[0024] Specific examples of the compound represented by the formula (VII) include bis (2-atallylooxychetyl) hydroxyethyl isocyanurate and bis (2-ataryloxypropyl) hydroxy. Annulate, bis (2-methacryloyloxychetyl) hydroxyethyl isocyanurate, vinyl

Kichetinole) isocyanurate, tris (2-ataryloxypropyl) isocyanurate, tris (2-acryloyloxybutyl) isocyanurate, tris (2-methacryloyloxychetyl) isocyanurate, tris (2-methacryloyloxypropyl) isocyanurate, There are tris (2-methacryloyloxybutyl) isocyanurate, but tris (2-methacryloyloxychetyl) isocyanurate and tris (2-methacryloyloxychetyl) isoyanurate are preferred. Royloxetyl) isocyanurate is particularly preferred.

[0025] Compound B has a rigid ring structure, and thus provides compound A with a high elastic modulus at a high temperature and a high glass transition temperature.

[0026] Further, the ultraviolet curable composition used in the present invention is a compound having a structure different from that of Compound A and Compound B, and has three or more (meth) attalyloyl groups, and It is preferable to further contain a compound C having a molecular weight of 250 or less per (meth) attalyl group. As the compound C, compounds having various structures that are not particularly limited can be used. Among them, a compound having a molecular weight of 200 or less per (meth) atalyloyl group is preferred, and a compound having 150 or less is preferred. More preferred.

Among them, the compound C is a compound represented by the following formula (VIII), formula (IX) or formula (X) It is preferable.

[0028] [Chemical 9]

(In the formula, R ¹ represents —CH 2 —, —CH 2 — or —CH ² —, and R ² represents a hydrogen atom or a methyl group.

2 4 3 6 4 8

, M represents 0 or 1. )

[0029] [Chemical 10]

(R ¹ 0) mD

0

CH ₂

D ~ (OR ¹ ) i 0CH ₂ -C- CH ₂ 0- (R ¾) _n -D ( ^IX )

CH ₂

0

(In the formula, R ¹ represents —CH 2 —, —CH 2 — or —CH 2 —, and each D independently represents a hydrogen atom or a formula

2 4 3 6 4 8

(III)

[0030] [Chemical 11]

z

0

(Wherein Z represents a hydrogen atom or a methyl group), at least three are groups represented by Formula III, and m represents 0 or 1. )

[0031] [Chemical 12] 00

(In the formula, R ¹ represents -CH-, -CH-or -CH-, and D represents the formula (III)

2 4 3 6 4 8

[0032] [Chemical 13]

(Wherein Z represents a hydrogen atom or a methyl group), at least three are groups represented by the formula (III), and m represents 0 or 1. )

[0033] Examples of the compound represented by the above formula (VIII), formula (IX) or formula (X) are shown below, and the molecular weight (M) of each compound and one (meth) atallyloyl group in each compound Per molecular weight (Mfg

). In the above formula, m is preferably 0.

[0034] 1.

A compound wherein R ² and m are as follows:

(a) R ² is a hydrogen atom and m force ^

(M; 296 Mfg; 99)

(b) Compound in which R ¹ is —CH ² —, R ² is a hydrogen atom, and m is 1.

twenty four

(M; 428 Mfg; 143)

(c) a compound in which R ¹ is —CH ² —, R ² is a hydrogen atom, and m is 1.

3 6

(M; 470 Mfg; 157)

(d) a compound in which R ¹ is —CH ² —, R ² is a hydrogen atom, and m is 1.

4 8

(M; 512 Mfg; 171)

When R ² is —CH, the molecular weight (M) of each compound increases by 52 and (Mfg) increases by 14.

Three

Add.

[0035] 2. A compound wherein RD and m in the above formula (IX) are as follows. (e) a compound in which three D's are an allyloyl group, one D is a hydrogen atom, and m is 0 (M; 298 Mfg; 99)

(f) R ^ -C H-, 3 D's are an allyloyl group, 1 D is a hydrogen atom, m

twenty four

The compound is 1

(M; 474 Mfg; 158)

(g) R ¹ is —CH 2 —, 3 D's are an taliloyl group, 1 D is a hydrogen atom, m

3 6

The compound is 1

(M; 530 Mfg; 177)

(h) R ¹ is —CH 2 —, 3 D's are an taliloyl group, 1 D is a hydrogen atom,

4 8

Compound with m force 1

(M; 586 Mfg; 195)

In (e) to (! i), in the case of a D-catacryloyl group, the molecular weight (M) of each compound increases by 52 and (Mfg) increases by 14.

(i) a compound in which four D's are an taliloyl group and m is 0

(M; 352 Mfg; 88)

(j) a compound in which R ¹ is —CH—, four D's are an allyloyl group, and m force ^

twenty four

(M; 528 Mfg; 132)

(k) a compound in which R ¹ is —CH 2 —, four D's are ataryloyl groups, and m force is 1

3 6

(M; 584 Mfg; 148)

(l) Compound in which R ^ -C H-, 4 D's are ataryloyl groups, and m force is 1

4 8

(M; 640 Mfg; 162)

In (i) to (l), in the case of a D force methacryloyl group, the molecular weight (M) of each compound increases by 66, and (Mfg) increases by 14.

3. A compound in which R D and m in the above formula (X) are as follows.

(m) a compound in which three D's are an allyloyl group, three D's are a hydrogen atom, and m is 0 (M; 416 Mfg; 139)

(n) R ¹ is —CH 2 —, three D's are attaylloyl groups, three D's are hydrogen atoms,

twenty four

Compound with m force 1 (M; 680 Mfg; 227)

In (m) and (n), when it is a D-catacryloyl group, the molecular weight (M) of each compound increases by 52 and (Mfg) increases by 14.

(o) a compound in which 6 D's are an taliloyl group and m is 0

(M; 578 Mfg; 96)

(p) a compound in which R ¹ is —CH—, six D's are an allyloyl group, and m ^

twenty four

(M; 842 Mfg; 140)

In (o) and (p), when it is a D force methacryloyl group, the molecular weight (M) of each compound increases by 84 and (Mfg) increases by 14.

[0037] Among these, (a), (b), (c), (e), (m) and (o) are more preferred because they can give a high elastic modulus after force hardening (a), (B), (e) and (o) are particularly preferred.

[0038] The ultraviolet curable composition used in the present invention preferably further contains a compound D having a cyclic structure and one radical polymerizable unsaturated double bond in the same molecule. As the compound D, compounds having various structures can be used. The ring structure may be an aromatic ring structure or a good alicyclic structure. Further, it may be a heterocyclic structure in which a nitrogen atom, an oxygen atom, a sulfur atom or the like is contained in the ring structure. Further, it may be a monocyclic structure or a polycyclic structure. Among these, a monocyclic alicyclic structure or aliphatic heterocyclic structure, or a polycyclic alicyclic structure or aliphatic heterocyclic structure is preferable. In addition, the group for introducing a radical polymerizable unsaturated double bond into the molecule is preferably a (meth) ataryloyl group.

[0039] In addition to the compound A and the compound B, a compound D having a cyclic structure and one radical polymerizable unsaturated double bond in the same molecule is contained in the ultraviolet curable composition. Curing shrinkage after UV irradiation is reduced. As a result, the warp of the optical disk can be suppressed as much as possible, and the occurrence of signal reading errors can be reduced. Such an effect is particularly remarkable when the optical disk is left in a high temperature and high humidity environment. An optical disk using an ultraviolet curable composition containing Compound D in addition to Compound A and Compound B is preferable because it has excellent durability when left in a high temperature and high humidity environment.

[0040] When compound D is added to the ultraviolet curable composition, it is used in the ultraviolet curable composition. The compound A is preferably a compound having two or more radically polymerizable unsaturated double bonds and a polycyclic structure in the same molecule, and the total content ratio of the compound A and the compound B is A composition containing 40% by mass or more based on the whole radical polymerizable compound is preferable.

[0041] Specific examples of compound D include isobornyl (meth) acrylate, norbornyl (meth) acrylate, 2- (meth) attayloxymethyl-2-methyl bicycloheptaneadamantyl ( (Meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopental (meth) acrylate, dicyclopentyl luxetyl (meth) acrylate, tetracyclode ester (meth) acrylate, cyclohexyl (meth) attaly , Benzyl (meth) acrylate, nourphenoxychetyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxy-1-3-phenoxypropyl (meth) Atarylate, Norphenoxytyl tetrahydrofurfuryl (meth) attareir , The force Purorataton denaturation tetrahydrofurfuryl (meth) Atari rate, Atari acryloyl morpholine, Fuenokishechi Le (meth) Atari rate, and the like.

Of these, isobornyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopental (meth) acrylate, taliloyl morpholine, and tetrahydrofurfuryl (meth) acrylate are preferable.

[0043] For the ultraviolet curable composition for optical discs, a radical polymerizable compound other than Compound A, Compound B, Compound C and Compound D can be used. Specific examples include the following monofunctional and polyfunctional (meth) acrylates.

[0044] Examples of monofunctional (meth) acrylates include ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl hexyl (meth) acrylate, nor (meth) acrylate, tridecylate. (Meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, isoamyl (meth) acrylate, isodecyl (meth) acrylate, isostearyl (meth) acrylate, 2-hydroxyethyl Examples include (meth) atarylate, 3-chloropropyl 2-hydroxypropyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxetyl (meth) acrylate, and the like.

[0045] Examples of the polyfunctional (meth) atarylate include 1,4-butanediol (meth) ataryl. , 3-methyl-1,5-pentanediol di (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, neopentylglycol di (meth) acrylate, 2-methyl-1,8-octane Diol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate Diol, polypropylene glycol di (meth) acrylate, neopentyl glycol 1 mol of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of di (meth) acrylate and trimethylol propane 3 moles or more of ethylene oxide or prop Diol or tri (meth) acrylate of triol obtained by addition of lopyrene oxide, poly (meth) acrylate of dipentaerythritol, ethylene oxide modified phosphate (meth) acrylate, ethylene oxide modified alkylated phosphate ( (Meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyether (meth) acrylate, jetylaminoethyl (meth) acrylate Rate, N-Buylpyrrolidone, N-Bielcaprolatatam, Bulether monomer and the like.

Among these compounds, triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, or trimethylolpropane. Multifunctional (meth) acrylates such as di- or tri (meth) acrylates and poly (meth) acrylates of dipentaerythritol are preferred because they can give high elasticity after curing.

[0047] The content ratio of Compound A and Compound B to the whole radical polymerizable compound is preferably 10% by mass or more, and the total content ratio of Compound A and Compound B is 40% by mass or more. It is preferable. Among them, the content ratios of Compound A and Compound B are more preferably 20% by mass or more, particularly preferably 30% by mass or more. Further, the total content ratio of Compound A and Compound B is more preferably 50% by mass or more, and particularly preferably 60% by mass or more. In such a range, a very rigid cured film can be obtained, and therefore, a very high glass transition temperature that is extremely hard even at high temperatures can be obtained. It hardly occurs. [0048] The content ratio of the compound C to the whole radical polymerizable compound is preferably 5 to 60%, more preferably 10 to 50%. When the content ratio of compound C is within this range, the resin layer after curing exhibits a high elastic modulus, which is preferable.

[0049] Further, the content ratio of the compound D to the entire radical polymerizable compound is preferably 5 to 40%, more preferably 5 to 20%. When the content ratio of Compound D is within this range, the shrinkage of curing shrinkage is expected to decrease, and the warpage of the disk can be reduced. Moreover, it is preferable also in obtaining a rigid cured film.

[0050] In the ultraviolet curable composition, a photopolymerization initiator can be used as necessary. As the photopolymerization initiator, any known and conventional ones can be used, but those of molecular cleavage type or hydrogen drawing type are suitable as the photopolymerization initiator used in the present invention. Examples of the photopolymerization initiator used in the present invention include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthixanthone, benzyl, 1-hydroxyhexylphenylketone, benzoinethyl ether, benzyldimethyl Ketal, 2-Hydroxy-1-2-Methyl 1-Phenolpropane-1-one, 1- (4-Isopropylphenyl) 2-Hydroxy-1-2-Methylpropane-1-one and 2-Methyl-1- (4-Methylthiophene- 2) Hydrogen-cleavable photopolymerization initiators such as 2-morpholinopropane 1-on and hydrogen-cleavage type photopolymerization initiators such as benzophenone, 4-phenol penzophenone, isophthalphenone, 4-benzoyl 4'-methyl diphenylsulfide Can be used.

[0051] Further, optional components to be added to the ultraviolet curable composition include the following, which can be used within the range not impairing the effects of the present invention. That is, as a sensitizer for photopolymerization initiators, for example, trimethylamine, methyldimethanolamine, triethanolamine, pdimethylaminoacetophenone, pdimethylaminoethyl benzoate, pdimethylaminoaminobenzoylamine, N, N dimethylbenzylamine, 4,4, -bis (diethylamino) benzophenone and the like, and an amine which does not cause an addition reaction with the photopolymerizable compound can be used in combination. Of course, it is preferable to select and use those which are excellent in solubility in an ultraviolet curable compound and do not inhibit the ultraviolet light transmittance. Moreover, in the ultraviolet curable resin composition of the present invention, if necessary, as an additive Further, surfactants, leveling agents, thermal polymerization inhibitors, hindered phenols, phosphites and other antioxidants, and hindered amines and other light stabilizers can also be used.

Next, the optical disk of the present invention will be described. The optical disk of the present invention comprises a dye recording layer (a

1

), A translucent light reflecting layer (t), a cured resin layer (c) of an ultraviolet curable composition, and a dye recording layer (b)

1 1

) And the light reflection layer (r) are laminated in this order. As a specific structure of such an optical disk, for example, there is an optical disk having the structure of FIG.

[0053] The optical disk in FIG. 1 has a dye recording layer (a) 2, a translucent light reflecting layer (t) 3 and a purple layer on a substrate (d) 1.

1 1 1 Cured resin layer (c) 4, dye recording layer (b) 5, light reflecting layer (r) 6, substrate (

1

d) An optical disc having a structure in which 7 and 7 are laminated in order. In Fig. 1, dye recording layer (a) 2 and translucent

twenty one

The light reflecting layer (t) 3 forms the first recording layer 21, and the dye recording layer (b) 5 and the light reflecting layer (r) 6 are the second recording layer.

1

A recording layer 22 is formed. Also, the translucent light reflecting layer (t) 3 and the dye recording layer (b) 5 are mutually connected.

1

It is laminated via a cured resin layer (c) 4 of the ultraviolet curable composition so as to face each other. Na

1

FIG. 1 also shows a convex recording track (group) 11 (first recording layer) and a convex recording track (group) 12 (second recording layer) with respect to the incident direction of light.

In the optical disk of the present invention, an adhesive layer 8 may be provided between the light reflecting layer (r) 6 and the substrate (d) 7.

2

(Figure 2). Further, between the cured resin layer (c) 4 and the dye recording layer (b) 5, the dye recording layer (a) 31,

1 2 Translucent light reflecting layer (t) 32 and cured resin layer (c) 33 of the UV curable composition in this order.

twenty two

It may be an optical disc having a structure in which one or two or more laminates (s) 23 are laminated. In this case, the cured resin layer (c) 4 and the dye recording layer (a) 31 are in contact with each other, and the dye recording layer (b) 5 and the cured resin layer are cured.

1 2

Laminate so that the oil layer (c) 33 contacts. The hardened resin layer (c) 33 has been described in detail so far.

twenty two

It is formed by the above-mentioned ultraviolet curable composition.

When two or more laminates (s) 23 are laminated, the dye recording layer (

1

a) and the cured resin layer (c) of another laminated body (s) adjacent to this laminated body (s).

2 1 2 2

Lamination is carried out through the cured resin layer of the ultraviolet curable composition described above in detail.

The example of the optical disk shown in FIG. 3 is an example in which only one layer (s) 23 is further laminated on the first recording layer 21 of the optical disk shown in FIG.

[0055] The optical disc of the present invention can be manufactured, for example, by the following steps. A method for manufacturing the optical disk shown in FIG. 1 will be described below.

[0057] First, a substrate (d) 1 having a guide groove for tracking a laser beam called a recording track (group) 11 is manufactured by injection molding polycarbonate resin.

1

The Next, after the azo dye is dissolved in the solvent, it is spun on the surface of the substrate (d) l on the recording track side.

1

The dye recording layer ( _a ) 2 is formed by coating. Furthermore, a silver alloy or the like is sputtered thereon.

1

Alternatively, the translucent light reflecting layer (t) 3 is formed by vapor deposition, and the first recording layer 21 is produced.

1

[0058] Next, a substrate (d) 7 having a guide groove for tracking laser light called a recording track (group) 12 is manufactured by injection molding polycarbonate resin.

2 Next, a light reflecting layer (r) 6 is formed by sputtering or vapor-depositing a silver alloy or the like. On top of this, the azo dye is dissolved in a solvent, and then the surface of the substrate (d) 7 on the recording track side is scanned.

2

The dye recording layer (b) 5 is formed by pin coating or the like, and the second recording layer 22 is produced.

[0059] An ultraviolet curable composition is formed on the surface of the translucent light reflecting layer (t) 3 of the substrate (d) having the first recording layer.

1 1

The substrate is coated with a dye recording layer (b) 5 by spin coating or the like, and one side or both sides of the bonded disk is irradiated with ultraviolet rays to form an ultraviolet curable composition. Curing is performed to form a cured resin layer (c) 4, and the optical disk shown in FIG. 1 is produced.

1

A method for manufacturing the optical disk shown in FIG. 2 will be described below.

[0061] First, a substrate (d) 1 having a guide groove for tracking laser light called a recording track (group) 11 is manufactured by injection molding polycarbonate resin.

1 Next, after the azo dye is dissolved in the solvent, the substrate (d) l

1 Dye recording layer ( _a ) 2 is formed on the surface of the recording track by spin coating or the like. Furthermore, a silver alloy or the like is sputtered thereon.

1

A semi-transparent light reflective layer (t) 3 is formed by coating or vapor deposition to produce the first recording layer 21.

1

On this, the cured resin layer (c) 4 of the ultraviolet curable composition for optical discs of the present invention is formed.

1 The recording track (group) 13 is transferred onto the surface using a mold. The process of transferring the recording track (group) 13 is as follows. Translucent light reflecting layer (t) 3 of substrate (d) 1

1 1 The UV curable composition for optical discs of the present invention is applied onto 1 and bonded to a mold for forming a recording track (group) 13 thereon, and one or both sides of the bonded discs are covered. In addition, the composition of the present invention is cured by irradiating with ultraviolet rays. Then peel the mold Then, an optical disk substrate in which the hardened resin layer (c) 4 is provided with the recording track (group) 13 is prepared.

1

The In addition, as a mold, if it has sufficient peelability with respect to the cured resin layer (c) 4,

1

Although it can be used without any particular limitation, a resin stamper is preferable in terms of productivity and cost. Examples of the resin stamper materials include acrylic resin, methacrylic resin, polycarbonate resin, polyolefin resin (especially amorphous polyolefin), polyester resin, polystyrene resin, epoxy resin, etc. What consists of these resin can be used. The UV curable composition for optical discs of the present invention has low adhesion to the cured resin layer (c) 4 and is peeled off

1

Polyolefin-based rosin is preferred because it is desired to have high properties!

[0063] Subsequently, this optical disk substrate has a recording layer (group) 13 of a cured resin layer (c) 4

1

After the azo dye is dissolved in the solvent, the dye recording layer is formed by spin coating or the like.

(b) 5 is formed. Further, the light recording layer (r) 6 is formed by sputtering or vapor-depositing a silver alloy or the like, and the second recording layer 22 is produced.

[0064] Next, a substrate (d) 7 having no recording layer is formed by injection molding of polycarbonate resin.

2 Make. An ultraviolet curable adhesive was applied to the surface of the light reflecting layer (r) 6 of the substrate having the two recording layers obtained as described above, and the substrate (d) 7

2 can be produced by irradiating ultraviolet rays from one or both sides of the laminated disc to cure the ultraviolet curable adhesive, thereby forming the adhesive layer 8.

A method for manufacturing the optical disk shown in FIG. 3 will be described below.

[0066] The first recording layer 21 and the cured resin layer (c) 4 in the optical disc shown in Fig. 2 are formed.

The first recording layer 21 is formed on the substrate (d) l shown in FIG.

1

Forming a cured resin layer (c) 4 of an ultraviolet curable composition having a recording track (group)

1

. Next, in the same manner as the method for forming the first recording layer 21 in the optical disc shown in FIG. 2, the laminate (s) 23 in FIG. 3 is formed. On this, the second recording layer 22 is formed in the same manner as the method for forming the second recording layer 22 in the optical disc shown in FIG. Finally, an ultraviolet curable adhesive was applied to the surface of the light reflecting layer (r) 6 of the second recording layer 22 and bonded to a polycarbonate resin substrate (d) 7 having no recording layer. One or both sides of the disc

2

Then, the optical disk shown in FIG. 3 can be produced by irradiating ultraviolet rays to cure the ultraviolet curable adhesive to form the adhesive layer 8. [0067] As the organic dye used for the recording layer, in addition to the azo dye, any organic dye that can form pits by laser light used for recording can be used without particular limitation. For example, cyanine, phthalocyanine, These include naphthalocyanine, anthraquinone, triphenylenomethane, pyrylium or thiapyrylium salt, squarylium, croconium, formazan, and metal complex dyes. In addition, a singlet oxygen quencher may be mixed with the dye. Quenchia is preferably a metal complex such as acetyl diacetate, bisdithio a-diketone or bisdithiol such as bisphenol dithiol, thiocatechol, salicylaldehyde oxime or thiobisphenolate. . Also, amine-based compounds having a nitrogen radical cation such as hindered amines are also suitable. As the recording layer material, a phase change recording material can be used in place of the organic dye, and a chalcogen alloy can be used as the material, and examples thereof include GeSbTe and AglnSbTe.

The materials used for the first recording layer 21 and the second recording layer 22 may be the same or different. In addition, the dye recording layer (a) of the laminate (s) is also a material used for other dye recording layers.

2

It's the same as, or it can be different.

[0068] Further, the translucent light reflecting layer and the light reflecting layer can be used without particular limitation as long as they can reflect and record / reproduce laser light in addition to the silver alloy, for example, gold, copper, Examples include metals such as aluminum and alloys thereof, and inorganic compounds such as silicon. The semitransparent light reflecting layer and light reflecting layer should be formed into a thin film by sputtering or vapor deposition using these materials. Can be obtained.

The translucent light reflecting layer is a light reflecting layer having an appropriate light transmissibility to such an extent that recording and reproduction of the second recording layer are possible. Specifically, the reflective layer preferably has a light transmittance of 40% or more for recording and reproducing information and an appropriate light reflectance (usually 30% or more). The thickness of the translucent light reflecting layer is usually preferably 50 nm or less. More preferably, it is 30 nm or less. More preferably, it is 25 nm or less.

The light reflecting layer of the second recording layer needs to have a high reflectance. High durability is also desirable. In order to ensure high reflectivity, the thickness of the light reflection layer is usually preferably 20 nm or more. More preferably, it is 30 nm or more. More preferably, it is 50 nm or more. However, In order to shorten the tact time of production and reduce the cost, it is preferable that the thickness is somewhat thin. More preferably, it is 300 nm or less.

[0069] Ultraviolet irradiation can be performed by a continuous light irradiation method using, for example, a metal halide lamp, a high-pressure mercury lamp, or the like, or by a flash light irradiation method described in USP5904795. The flash irradiation method is more preferable in that it can be cured efficiently. The gel fraction of the cured product is preferably 70% to 100%, more preferably 85% to 100%. As the substrate used in the optical disk of the present invention, those usually used as optical disk substrates can be used, and in particular, a polycarbonate substrate can be suitably used.

The thickness of the substrate is preferably 0.1 to 2 Omm, more preferably 0.3 to 1.5 mm or more.

[0070] The ultraviolet curable composition used in the optical disc of the present invention is not limited to the use of write-once DVD-R and DVD + R, but is rewritable DVD-RW, DVD + RW, DVD- DVDs such as RAM, or optical disks in which a light-transmitting layer is formed by laminating a cured film of an ultraviolet curable composition on an optical disk substrate, for example, blue-violet laser light is used as laser light for reading and writing information. It can also be used in the production of the next-generation optical discs used (product name “Blu-ray” manufactured by Sony, product name “HD-DVD”).

Example

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Examples and Comparative Examples)

The composition materials shown in Tables 1 to 3 below were used to heat and dissolve each composition material at 60 ° C. for 3 hours to prepare ultraviolet curable compositions for each Example and each Comparative Example.

[0072] Next, the optical disk of Fig. 2 was produced by the method described above. First, a substrate (d) 1 having a guide groove for tracking a laser beam called a recording track (group) was manufactured by injection molding polycarbonate resin. Next, the azo dye is solvent

1

After being dissolved in the dye recording layer (by spin coating on the surface of the substrate (d) 1 on the recording track side ( a) 2 formed. Further, a translucent light reflecting layer (t) is formed by sputtering a silver alloy thereon.

1 1

3 was formed, and the first recording layer 21 was produced.

[0073] On the translucent light-reflecting layer (t) 3 of the substrate (d) 1, purple for each of the above examples and each of the comparative examples

1 1

The external-line curable composition was applied, bonded to a resin stamper, and irradiated with ultraviolet rays from the resin stamper side of the bonded disk to cure the ultraviolet curable composition. Thereafter, the resin stamper was peeled off to form a cured resin layer (c) 4 having a film thickness of about 55 m to which the recording track (group) was transferred. Here, the resin stamper is a polyolefin resin

1

Was produced by injection molding. Subsequently, the cured resin layer (c) 4 of this optical disk substrate

A azo dye was dissolved in a solvent on the surface having the recording track (group) 1 and a dye recording layer (b) 5 was formed by spin coating. Further, a light recording layer (r) 6 was formed by sputtering a silver alloy to produce a second recording layer 22.

[0074] Next, a substrate (d) 7 having no recording layer is formed by injection molding of polycarbonate resin.

2 Make. On the surface of the light reflecting layer (r) 6 of the substrate having the two recording layers obtained as described above, an ultraviolet curable adhesive Dicure Clear SD-694 (manufactured by Dainippon Ink & Chemicals, Inc.) ) Is applied and bonded to the substrate (d) 7, and the surface of the substrate (d) 7 of the bonded disk

2 2 was irradiated with ultraviolet rays to cure the ultraviolet curable adhesive, and an adhesive layer 8 was formed. Thus, the optical disk shown in FIG. 2 was produced.

[0075] (Measurement of jitter and push-pull signal)

The jitter and push-pull signal of the mark length of the reproduction signal in the dye recording mark of each of the manufactured optical discs of Examples and Comparative Examples were measured. In order to measure jitter, an evaluation machine (Pulstec DDU-1000, maximum recording power 15 mW) equipped with a semiconductor laser with a wavelength of 657 nm (NA = 0.65) was used for the second recording layer of each optical disc. , Recording linear density 9. lmZs, 8-16 modulation EFM + signal, recording signal asymmetry is near 0 (in this case, modulation is more than 0.6) mark length 3T-14T mark Was recorded. Thereafter, the recorded signal was reproduced with a reproduction linear velocity density of 3.8 mZs and a reproduction power of 0.7 mW, and the average value of jitter (signal deviation) of the reproduction signal of the mark having a mark length of 3T to 14T was measured. Tables 1 to 3 show the optical disks of the examples and comparative examples and the evaluation results. If the jitter is 8% or less, the recording characteristics are good, and the Push-Pull signal is The larger the value, the better.

[0076] (Durability test under high temperature and high humidity environment)

An exposure test was conducted in a high-temperature, high-humidity environment at 80 ° C and 85% RH for 96 hours using PR-2PK manufactured by ESPEC Corporation. Table 3 shows the optical disks and evaluation results of each example.

[0077] (Measurement of warpage)

The warpage angle of each manufactured optical disk was measured under normal temperature and humidity conditions using an inline warpage inspection device S3 from Basra Corporation. Warpage is good within 0.3 °. Table 3 shows the optical disks and evaluation results for each example.

[0078] (PI error measurement)

The produced disc was recorded with a commercially available recording drive, and PI error was measured by SA-300 manufactured by Audio Development Corporation. The PI error ratio (number of errors after test, number of errors before test) was calculated and evaluated. Table 3 shows the optical disks of each example and the evaluation results.

[0079] [Table 1]

[0080] [Table 2]

[Table 3]

The abbreviations in Table 1 to Table 3 represent the following compounds.

• TCDDA: Tricyclodecane dimethanol diatalate

• TAEIC: Tris (2-Ataliloylochetyl) isocyanurate

ΤΜΡΤΑ: Trimethylolpropane triatrate

・ ΤΜΡ (3ΕΟ) ΤΑ: Tritalylate of triol obtained by adding 3 mol of ethylene oxide to 1 mol of trimethylolpropane

・ ΤΜΡ (15ΕΟ) ΤΑ: Triatalylate of triol obtained by adding 15 mol of ethylene oxide to 1 mol of trimethylolpropane

• DP (6EO) TA: Tritalylate of hexaalcohol obtained by adding 6 mol of ethylene oxide to 1 mol of dipentaerythritol

NPGDA: Neopentyl glycol ditalylate

• UA-1: Urethane acrylate which is a reaction of polytetramethylene glycol (molecular weight 850), tolylene diisocyanate and hydroxylate acrylate at a molar ratio of 12Z2.

• V-5530: Epoxy acrylate (Otsukamoto Ink Chemical Co., Ltd.)

• ACMO: Atariloyl morpholine

IBXA: Isobol acrylate

-FA-511 A: Dicyclopentenyl Acrylate (manufactured by Hitachi Chemical Co., Ltd.)

• FA-513A: Dicyclopentanyl Acrylate (manufactured by Hitachi Chemical Co., Ltd.)

• HCPK: 1-Hydroxycyclohexyl phenyl ketone • TPO: Trimethylphenyldiphenylphosphine oxide

• lrg.184: Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.)

• MPTMS: Mercaptopropyltrimethoxysilane

• EPTMS: Epoxypropinoletrimethoxysilane

[0083] << Summary of evaluation results >>

As is apparent from Tables 1 to 3, the optical disks of Examples 1 to 8 according to the present invention show excellent results when the jitter of the second recording layer is 8% or less. The 15 optical disk had a sufficiently large push-pull.

On the other hand, in Comparative Examples 1 to 4, jitter could not be measured, push-pull was very low, and the characteristics were insufficient as an optical disk.

Industrial applicability

The present invention can be applied to an optical disc having a structure provided with a plurality of recording layers.

Claims

The scope of the claims

A dye recording layer (a), a translucent light reflecting layer (t), a cured resin layer (c) of an ultraviolet curable composition,

1 1 1

The dye recording layer (b) and the light reflecting layer (r) have a structure in which they are laminated in this order,

The ultraviolet curable composition is

,as well as

[Chemical 14]

An optical disc characterized by comprising a compound B having a trivalent partial structure represented by the formula:

[2] Further, a dye recording layer (a), a translucent light reflecting layer (t), and a curing agent of the ultraviolet curable composition

twenty two

One or two or more laminates (s) in which the oil layer (c) is laminated in this order, the cured resin layer (c),

2 1 The cured resin layer (c) and the dye recording layer (a) are in contact with the dye recording layer (b).

1 2

The dye recording layer (b) and the cured resin layer (c) are in contact with each other, and two or more laminates (s) are stacked.

2

In the case of layering, the dye recording layer (a) of one laminate (s) and adjacent to the laminate (s)

1 2 1 Other laminates (s)

2 of the cured resin layer (c)

2. The optical disc according to claim 1, wherein the optical discs are laminated so as to be in contact with each other.

[3] The dye recording layer (a) is provided on the substrate (d), and the light reflecting layer (r) is provided on the substrate (d).

1 1 2

The optical disk according to claim 1.

4. The optical disc according to claim 3, further comprising an adhesive layer between the light reflecting layer (r) and the substrate (d).

2

[5] The compound A is represented by the formula (II)

X ¹ -R ¹ -O-R ² -O-R ³ -X ¹ (II)

(Where X ¹ is the formula (III) [Chemical 15]

(Wherein Z represents a hydrogen atom or a methyl group), R ¹ and R ³ are — (OC _n H) − (where n represents an integer of 1 to 4, m represents 1 or 2, and the oxygen atom in the formula is bonded to X ^1.

2n m

Match. R ² is a group represented by formula (IV),

[Chemical 16]

Or formula (VI)

[Chemical 18]

It is a divalent group represented by 2. The optical disk according to claim 1, wherein the optical disk is a compound represented by: The compound B is represented by the formula (VII)

[Chemical 19]

(VII)

The oxygen atom inside binds to X ¹ or X ² . ). 2. The optical disk according to claim 1, which is a compound represented by

[7] The ultraviolet curable composition contains the compound A and the compound B in an amount of 10% by mass or more based on the whole radical polymerizable compound, and the total content of the compound A and the compound B. 2. The optical disc according to claim 1, wherein the ratio is 40% by mass or more.

[8] The ultraviolet curable composition further comprises a compound C having 3 or more (meth) taroloyl groups and having a molecular weight of 250 or less per (meth) attaroyl group. 1. Optical disk according to 1.

[9] The compound A is a compound having two or more radically polymerizable unsaturated double bonds and a polycyclic structure in the same molecule, and the ultraviolet curable composition comprises the compound A and the compound B and a compound D having a cyclic structure and one radical polymerizable unsaturated double bond in the same molecule, and the total content ratio of the compound A and the compound B is the whole radical polymerizable compound The optical disk according to claim 1, wherein the optical disk is a composition containing 40% by mass or more based on the mass.