JP2000280623A - Optical information recording medium and method for recording information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat mode type optical information recording medium having excellent stability at high temperature and high humidity and performing high recording sensitivity by incorporating a cationic polymer component and a specific anionic cyanine dye component in a recording layer in the medium. SOLUTION: In the heat mode type optical information recording medium, a recording layer contains a cationic polymer and an anxonic cyanine dye represented by the formula (wherein DYE+ is a monovalent cyanine dye cation, and n is an integer of 1 or above). In this case, the polymer and the cyanine dye of one type may be used, or of two or above types may be used. To take a charge equilibrium, cation or anion may be contained except the both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat mode optical information recording medium and an information recording method capable of recording and reproducing information using a laser beam. In particular, the present invention is suitable for recording information using near-infrared laser light or visible laser light, for example, a write-once optical disk (CD-R) or a write-once digital video disk (DVD-R). ) Relates to a heat mode type optical information recording medium.

[0002]

2. Description of the Related Art Conventionally, an optical information recording medium (optical disk) on which information can be recorded only once by a laser beam has been known. This optical information recording medium is a write-once CD (so-called C
A typical structure thereof is that a recording layer made of an organic dye, a light reflection layer made of a metal such as gold, and a protective layer made of a resin are laminated in this order on a transparent disk-shaped substrate. Things. Recording of information on the laminate is performed by irradiating near-infrared laser light (usually laser light having a wavelength of about 780 nm) to locally generate heat and deform the recording layer. On the other hand, reading (reproducing) information is usually performed by irradiating a laser beam having the same wavelength as the recording laser beam to reflect a portion where the recording layer is heated and deformed (recorded portion) and a portion where the recording layer is not deformed (unrecorded portion). It does this by detecting differences in rates.

In recent years, with the spread of personal computers and the like, optical information recording media having a higher recording density have been demanded. To increase the recording density, it is effective to reduce the diameter of the laser beam to be irradiated, and it is theoretically known that laser light having a shorter wavelength can be reduced to a smaller diameter, which is advantageous for increasing the density. Have been. Therefore, an optical disk for performing recording and reproduction using a laser beam having a wavelength shorter than 780 nm, which has been conventionally used, is being developed. For example, it is called a write-once digital video disk (so-called DVD-R). Optical disks have been proposed.
This optical disc has a track pitch of 1.6 of CD-R.
A recording layer made of a dye is provided on a transparent disc-shaped substrate having a diameter of 120 mm on which a 0.8 μm pre-groove smaller than μm is formed, and a light reflection layer and a protective layer are usually provided on the recording layer. It is manufactured to have a structure in which two disks or a disk-shaped protective substrate having the same shape as the disk are bonded with an adhesive with the recording layer inside. The DVD-R uses visible laser light (normally 630n).
Recording and reproduction are performed by irradiating a laser beam having a wavelength in the range of m to 680 nm.
It is said that recording at a higher density than -R is possible.

In designing the DVD-R, since the wavelength of the laser beam used for recording and reproduction is shorter than that of the CD-R, the maximum absorption wavelength of the dye used in the dye recording layer must be shortened accordingly. There is. However, it is generally known that the maximum absorption wavelength of a dye becomes longer as the spread of the pi-electron system, which causes light absorption, becomes longer. Particularly, the cyanine dye which has been practically used in many optical discs in the past is known. In this case, the longer the conjugated methine chain, the longer the wavelength. That is, in order to shorten the maximum absorption wavelength of the dye, it is effective to shorten the length of the conjugated methine chain.
However, when the length of the conjugated methine chain is shortened, the extinction coefficient is decreased, so that the recording sensitivity (the modulation degree) is inevitably reduced. Therefore, simply using a conventional CD
It is difficult to obtain satisfactory performance as a dye for DVD-R only by shortening the length of the conjugated methine chain of the dye for -R to shorten the absorption maximum wavelength.

On the other hand, in a CD-R, the reflectance at 780 nm must be high enough to be read by a commercially available CD player. In order to increase the amount of light reflected by the metal light reflection layer provided on the dye recording layer, it is preferable that the light absorption by the dye is low, and it is considered that the absorption maximum wavelength of the dye should be shorter. . However, when a dye having an absorption maximum wavelength on the short wavelength side is used, 780 nm
In this case, the change in the reflectance between the recorded portion and the unrecorded portion is reduced, and it becomes difficult to detect the difference. Therefore, in the conventional CD-R, a dye having a high reflectance and a high recording sensitivity is selected and used. For example, as such a dye, a cyanine dye having a benzoindolenine skeleton described in JP-A-64-40382 is preferably used.
However, conventional cyanine dyes are not necessarily satisfactory in both reflectance and recording sensitivity, and further improvement has been desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat mode optical information recording medium having a high recording sensitivity and a method of recording information when recording information using a laser beam. In particular, an object of the present invention is to provide an optical information recording medium and an information recording method capable of obtaining high recording sensitivity even when using visible laser light (for example, red laser light having a wavelength of 630 to 680 nm). Another object of the present invention is to provide a heat mode type optical information recording medium which is excellent in stability under high temperature and high humidity and can achieve high recording sensitivity.

[0007]

The above object has been attained by the following items which specify the present invention and preferred embodiments thereof. (1) A heat mode type optical information recording medium having a recording layer on a substrate on which information can be recorded by irradiating a laser beam, wherein the recording layer comprises a cationic polymer component and the following formula (I) An optical information recording medium comprising an anionic cyanine dye component represented by the formula:

Embedded image [Wherein, DYE ⁺ represents a monovalent cyanine dye cation, and n represents an integer of 1 or more. (2) The optical information recording medium according to the above (1), wherein the cyanine dye cation is represented by the following formula (II).

Embedded image In the formula, Za and Zb each independently represent an atomic group necessary for completing a 5- or 6-membered nitrogen-containing heterocyclic ring;
¹ and R ² each independently represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.
L ¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent a substituted or unsubstituted methine group, and when there is a substituent on L ^{1 to} L ⁵ , they are linked to each other to form a ring You may. j represents 0, 1 or 2, and k represents 0 or 1. (3) the cyanine dye cation is represented by the following formula (IIA):
The optical information recording medium according to (1) above,

Embedded image [Wherein, Z ¹ and Z ² each independently represent a group of atoms necessary to complete an indolenine nucleus or a benzoindolenine nucleus, and R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group. R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group; L ¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent an alkyl group; It independently represents a substituted or unsubstituted methine group, and when there is a substituent on L ^{1 to} L ⁵ , they may be linked to each other to form a ring. j represents 0, 1 or 2, and k represents 0 or 1. (4) The optical information recording medium according to the above (2) or (3), wherein j is 0 or 1 in the formula (II) or (IIA). (5) The optical information recording medium according to any one of (1) to (4), wherein a light reflection layer is provided on the recording layer. (6) The light reflection layer is made of Cr, Ni, Pt, Cu, Ag, A
The optical information recording medium according to the above (5), comprising a metal selected from u, Al and stainless steel or an alloy thereof. (7) The optical information recording medium according to (5) or (6), wherein a protective layer is provided on the light reflecting layer. (8) The substrate has a pre-groove having a track pitch of 0.6 μm or more and 0.9 μm or less, and a thickness of 0.6 ±
The optical information recording medium according to any one of (1) to (7) above, wherein the optical information recording medium is a 0.1 mm transparent disk, and the recording layer is provided on the surface on the side where the pregroove is formed. (9) The substrate has a pre-groove having a track pitch of 0.6 μm or more and 0.9 μm or less, and has a diameter of 120 μm.
A transparent disc having a thickness of ± 0.3 mm and a thickness of 0.6 ± 0.1 mm, on which two recording layers provided with the recording layer on the side where the pre-groove is formed, is subjected to each recording. 1.2 ± 0.2mm thickness, joined so that layer is inside
The optical information recording medium according to any one of the above (1) to (8). (10) The substrate has a pregroove having a track pitch of 0.6 μm or more and 0.9 μm or less, and has a diameter of 120 μm.
A transparent disc having a thickness of ± 0.3 mm and a thickness of 0.6 ± 0.1 mm, and a laminate having the recording layer provided on a side of the substrate on which a pregroove is formed, the same as the transparent disc; Optical information recording according to any one of the above (1) to (8), having a thickness of 1.2 ± 0.2 mm, in which a transparent disc-shaped protective substrate having a shape is joined so that the recording layer of the laminate is on the inside. Medium. (11) The substrate has a pre-groove having a track pitch of 1.4 μm or more and 1.8 μm or less, and a thickness of 1.2 ±.
The optical information recording medium according to any one of the above (1) to (7), wherein the optical information recording medium is a 0.2 mm transparent disk and the recording layer is provided on the surface on the side where the pregroove is formed. (12) An information recording method for recording information by irradiating the optical information recording medium according to any one of (1) to (10) with a laser having a wavelength of 630 nm to 680 nm. (13) Any one of the above (1) to (7) or (1)
The optical information recording medium of 1) has a wavelength of 750 nm or more and 800
An information recording method in which information is recorded by irradiating a laser of nm or less.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The optical information recording medium of the present invention is characterized in that the recording layer contains a cationic polymer and an anionic cyanine dye represented by the following formula (I).

[0009]

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In the formula, DYE ⁺ represents a monovalent cyanine dye cation, and n represents an integer of 1 or more. The upper limit of n is not particularly limited, but is preferably about 10.

The cyanine dye cation in the anionic cyanine dye used in the present invention is preferably a cation represented by the following formula (II).

[0012]

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[0013] SO in formula (I) ₃ ^- preferably is substituted by at least two of the heterocyclic ring formed by R ^1, R ^2, Za or Zb of Formula (II), particularly preferred R ¹ It is replaced by R ^2.

In the formula (II), Za and Zb each independently represent an atom group necessary for completing a 5- or 6-membered nitrogen-containing heterocyclic ring. R ¹ and R ² are each independently
Represents an alkyl group or an aryl group, which may have a substituent. L ¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent a substituted or unsubstituted methine group. Also L
Ring may be formed connected to each other in the case of having a substituent on the ¹ ~L ^5. j represents 0, 1 or 2, and k represents 0 or 1.

5 or 6 members represented by Za and Zb
Examples of the nitrogen-containing heterocyclic ring (nucleus) include a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a thiazoline nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthooxazole nucleus, an oxazoline nucleus, a selenazole nucleus,
Benzoselenazole nucleus, naphthoselenazole nucleus, selenazoline nucleus, tellurazole nucleus, benzotellurazole nucleus, naphthotellurazole nucleus, tellurazoline nucleus, imidazole nucleus, benzimidazole nucleus, naphthimidazole nucleus, pyridine nucleus, quinoline nucleus, isoquinoline nucleus, imidazo [4,5-b] quinoxaline nucleus, oxadiazole nucleus,
Examples thereof include a thiadiazole nucleus, a tetrazole nucleus, and a pyrimidine nucleus. Among these, a benzothiazole nucleus, an imidazole nucleus, a naphthoimidazole nucleus, a quinoline nucleus, an isoquinoline nucleus, an imidazo [4,5-b] quinoxaline nucleus, a thiadiazole nucleus, a tetrazole nucleus, and a pyrimidine nucleus are preferable. In these rings,
Further, a benzene ring and a naphthoquinone ring may be condensed.

The above 5- or 6-membered nitrogen-containing heterocyclic ring may have a substituent. Preferred examples of the substituent (atom) include a halogen atom, a substituted or unsubstituted alkyl group, and an aryl group. As the halogen atom, a chlorine atom is preferable. The alkyl group is preferably a linear alkyl group having 1 to 6 carbon atoms. Examples of the substituent of the alkyl group include an alkoxy group (eg, methoxy) and an alkylthio group (eg, methylthio). As the aryl group, phenyl is preferred.

The alkyl group represented by R ¹ and R ² may have a substituent, and preferably has 1 to 1 carbon atoms.
18 (more preferably 1 to 8, particularly preferably 1 to 6)
Is a linear, cyclic or branched alkyl group.
The aryl group represented by R ¹ and R ² may have a substituent, and is preferably an aryl group which may have a substituent having 6 to 18 carbon atoms.

Examples of preferred substituents on the alkyl or aryl group represented by R ¹ and R ² include the following: a substituted or unsubstituted aryl group having 6 to 18 carbon atoms. (Eg, phenyl, chlorophenyl, anisyl, toluyl, 2,4-di-t-amyl, 1-naphthyl), alkenyl group (eg, vinyl, 2-methylvinyl), alkynyl group (eg, ethynyl, 2-methylethynyl) , 2-phenylethynyl),
A halogen atom (eg, F, Cl, Br, I), a cyano group, a hydroxyl group, a carboxyl group, an acyl group (eg, acetyl, benzoyl, salicyloyl, pivaloyl), an alkoxy group (eg, methoxy, butoxy, cyclohexyloxy), Aryloxy group (for example, phenoxy, 1-naphthoxy), alkylthio group (for example, methylthio, butylthio, benzylthio, 3-methoxypropylthio), arylthio group (for example, phenylthio, 4-chlorophenylthio), alkylsulfonyl group (for example, Methanesulfonyl, butanesulfonyl), arylsulfonyl group (for example, benzenesulfonyl, paratoluenesulfonyl), and having 1 to 10 carbon atoms
A carbamoyl group, an amide group having 1 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, and 2-1 carbon atom
A heteroaromatic ring such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl, a pyrrolidine ring, a piperidine ring, a morpholine ring, a pyran ring, a thiopyran ring;
An aliphatic heterocycle such as a dioxane ring and a dithiolane ring).

In the present invention, R ¹ and R ² each represent an unsubstituted linear alkyl having 1 to 8 carbon atoms (preferably 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms). Directly substituted with an alkoxy group (especially methoxy) or alkylthio group (especially methylthio) having 1 to 8 carbon atoms (preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms). It is preferably a chain alkyl group.

L¹~ L^FiveThe methine group represented by
You may have. Examples of preferred substituents include carbon
An alkyl group having 1 to 18 atoms, an aralkyl group, and
Note R ¹And R^TwoAn alkyl or aryl group represented by
Listed as examples of preferred substituents possessed by
be able to. Among these, alkyl groups (eg, methyl
), Aryl group (eg, phenyl), halogen atom
(Eg, Cl, Br) and an aralkyl group (eg, benzyl)
preferable. In the present invention, j is 0 or 1.
Is preferred.

The substituents on L ^{1 to} L ⁵ may be linked to each other to form a ring. Preferred number of ring members is 5 or 6
And two or more of these rings may be condensed. The linking position depends on the number of methine chains formed. For example, when the methine chain formed by L ^{1 to} L ⁵ is a pentamethine chain, the preferred linking positions are L ¹ and L ³ , L ² and L ⁴ , and L ³ and L ⁵ . The connecting position in the case of forming a double condensed ring is L ¹ and L ³ and L ^5. In this case, L ¹ and R ¹ , L ⁵ and R ² , and L ³ and R ²
May be connected to each other to form a ring, and the number of ring members is preferably a 5- or 6-membered ring. In the present invention, the ring formed by the substituents on L ^{1 to} L ⁵ is preferably a cyclohexene ring.

The cyanine dye cation of the formula (II) is preferably a cation represented by the following formula (IIA).

[0023]

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In the formula (IIA), Z ¹ and Z ² represent an atomic group necessary for completing an indolenine nucleus or a benzoindolenine nucleus. R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group. R ¹ , R ² , L ¹ , L ² , L
³ , j and k in L ⁴ and L ⁵ are the same as those in the formula (II).

The indolenine nucleus or benzoindolenine nucleus represented by Z ¹ and Z ² may have a substituent. Examples of the substituent (atom) include a halogen atom and an aryl group. As the halogen atom, a chlorine atom is preferable. Further, as the aryl group, phenyl is preferable.

The alkyl group represented by R ³ , R ⁴ , R ⁵ and R ⁶ is preferably a linear alkyl group having 1 to 18 carbon atoms.
It is a branched or cyclic alkyl group. R ³ and R ⁴ , and R ⁵ and R ⁶ may be connected to each other to form a ring. Further, the alkyl group represented by R ³ , R ⁴ , R ⁵ and R ⁶ may have a substituent. Preferred examples of the substituent include those described as examples of preferred substituents of the alkyl group or the aryl group represented by R ¹ and R ² . In the present invention, R
^The alkyl groups represented by ³ , R ⁴ , R ⁵ and R ⁶ are each preferably a straight-chain unsubstituted alkyl group having 1 to 6 carbon atoms (particularly, methyl and ethyl). .

Preferred specific examples of the anionic cyanine dye represented by the formula (I) according to the present invention are described below.

[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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Next, the cationic polymer used together with the anionic cyanine dye of the present invention will be described in detail. The cationic polymer means a polymer having a positive charge at a polymer site, and is preferably represented by the following formula (III).

[0037]

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In the formula, A represents a monomer unit having a quaternary ammonium ion (including a nitrogen-containing heterocyclic compound such as pyridinium), and B represents a monomer unit having no quaternary ammonium salt. You may have. p and q represent the weight ratio (% by weight) of the constituent monomers of A and B, respectively. The sum of p is 2% or more 1
00% or less, the total of q is 0 or more and 98% or less, preferably, p is 2% or more and 60% or less, and q is 40% or more and 98% or less.
It is as follows. The cationic polymer in the present invention preferably has a weight average molecular weight of 100 or more and 1,000,000 or less, more preferably 1,000 or more and 100,0 or less.
00 or less. Specifically, the following compounds may be mentioned.

[0039]

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[0040]

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[0041]

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When the compound containing a repeating unit represented by the formula (III) is a polymer consisting of only the same repeating unit derived from a monomer having a reactive functional group,
Although it can be a homopolymer, it may be a copolymer.
As the copolymer, an alternating copolymer, a random copolymer,
Any of block polymers and the like may be used. In addition, the terminal group can be various depending on the synthesis raw material and the like.

Tables 1 and 2 show examples of combination compounds of the anionic cyanine dye component represented by the formula (I) and the cationic polymer component of the present invention.

[0044]

[Table 1]

[0045]

[Table 2]

The anionic cyanine dye and the cationic polymer according to the present invention may be used alone or in combination of two or more. Further, in order to balance the charge, a cation or an anion may be contained in addition to the both. The compound according to the present invention can be easily synthesized with reference to the description of the following known documents.

These documents include, for example, F.
M. Hammer, "The Cyanine Soybeans and Related Compounds 5 (Interscience Publishers, NY, 1964), p. 55 et seq .; Nikolai Tuturkov, Jurgen Fabian, Akim Meerhorn, Filitz・ Dietz, Aria Tadzière (Nikolai Tyutyulkov, Jurgen Fabian, Achim U
Lehlhorn, Fritz Dietz, Alia Tadjer) “Polymethine soybean”, St. Kliment Ohridski University Press, Sofia (St. Kliment Ohridski Uni)
versity Press, Sophia), pp. 23-38; DMSturmer, "Heterocyclic, Compounds-Special Topics in Heterocyclic Chemistry".
Compounds-Special topics in heterocyclic chemistr
y), Chapter 18, Section 14, pp. 482-515, John Wiley & Sons
) Sha, New York, London, (1977);
"Rodd's Chemistry of Carbon Compounds", (2n
d.Ed.vol.IV, part B, 1977), Chapter 15, Chapter 3
69-422, (2nd. Ed. Vol. IV, part B, 1985), Chapter 15, pages 267-296, Elsbyer Science Public Company, Inc. (Elsv)
ier Science Public Company Inc.), New York, and the like.

The ionic complex of the anionic cyanine dye and the cationic polymer is specifically represented by the formula (I)
(Eg, salts with cations such as sodium ion, potassium ion, ammonium ion, pyridinium ion, triethylammonium ion, and N-ethylpyridinium ion); and cationic polymers Cl ⁻ , Br ⁻ , I ⁻ , a salt formed in combination with an anion such as p-toluenesulfonate in a suitable solvent, for example, methanol, water, or a mixture thereof, followed by precipitation. .

The optical information recording medium of the present invention has a recording layer containing an ion complex of an anionic cyanine dye represented by the above formula (I) and a cationic polymer on a substrate. The ion complex according to the present invention can be advantageously used in a CD-R or DVD-R as an optical information recording medium. In particular,
In the DVD-R type optical information recording medium, a dye having an indolenine nucleus or a benzoindolenine nucleus having a trimethine chain among the cyanine dyes represented by the above formula (IIA) is advantageously used.

The optical information recording medium of the present invention preferably has the following configuration. The CD-R type optical information recording medium has a diameter of 120 ± 0.3 mm and a thickness of 1.2 ± with a pre-groove having a track pitch of 1.4 to 1.8 μm.
It is preferable that a recording layer, a light reflection layer, and a protective layer are provided in this order on a 0.2 mm transparent disk-shaped substrate. The DVD-R type optical information recording medium preferably has the following two aspects. That is, a recording layer and a light reflection layer are provided on a transparent disc-shaped substrate having a diameter of 120 ± 0.3 mm and a thickness of 0.6 ± 0.1 mm on which a pre-groove having a track pitch of 0.6 to 0.9 μm is formed. The two laminated bodies thus formed are joined so that the respective recording layers are on the inside, and have a thickness of 1.2 ± 0.2 mm, or a track pitch of 0.6 to 0.2 mm. 9 μm
A laminate in which a recording layer and a light reflection layer are provided on a transparent disc-shaped substrate having a diameter of 120 ± 0.3 mm and a thickness of 0.6 ± 0.1 mm on which a pre-groove is formed; A transparent disk-shaped protective substrate of the same shape as the disk-shaped substrate is joined so that the recording layer is on the inside, and the thickness is 1.2 ± 0.2.
mm. The above D
The VD-R type optical information recording medium may have a configuration in which a protective layer is further provided on the light reflecting layer.

Hereinafter, a method for manufacturing an optical information recording medium will be described. The DVD-R type optical information recording medium is basically a CD-R optical recording medium except that a substrate on which a pre-group having a narrower track pitch is formed than a CD-R is used in order to achieve a higher recording density. It can be manufactured using a material used for manufacturing an optical information recording medium of -R. That is, the optical information recording medium of the DVD-R is
A recording layer, and a light reflection layer, and if desired, a laminate in which a protective layer is formed in order, two sheets are formed, and these two sheets are joined with an adhesive, or alternatively, the laminate and the laminate, It can be manufactured by bonding a substrate and a disk-shaped protective substrate having the same shape with an adhesive in the same manner. Therefore, in manufacturing the DVD-R optical information recording medium, the steps other than the final step of bonding the substrates are performed in the same manner as the CD-R optical information recording medium.

The optical information recording medium of the present invention can be manufactured, for example, by the following method. The substrate of the optical information recording medium can be arbitrarily selected from various materials used as the substrate of the conventional optical information recording medium. As the substrate material, for example, glass; polycarbonate; acrylic resin such as polymethyl methacrylate;
Examples thereof include polyvinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymer; epoxy resins; amorphous polyolefins and polyesters, and these may be used in combination if desired. Note that these materials can be used in the form of a film or a rigid substrate. Among the above materials, polycarbonate is preferred from the viewpoints of moisture resistance, dimensional stability, cost, and the like.

An undercoat layer may be provided on the surface of the substrate on which the recording layer is provided, for the purpose of improving flatness, improving adhesive strength, and preventing the recording layer. Examples of the material of the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene / vinyltoluene copolymer, and chlorosulfonate. Polymeric substances such as polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, etc .; and silane coupling agents And the like. The undercoat layer is formed by dissolving or dispersing the above substances in an appropriate solvent to prepare a coating solution, and then applying the coating solution to the substrate surface by a coating method such as spin coating, dip coating, or extrusion coating. can do.
The thickness of the undercoat layer is generally in the range of 0.005 to 20 μm, preferably in the range of 0.01 to 10 μm.

On the substrate (or the undercoat layer), irregularities (pre-grooves) representing information such as tracking grooves or address signals are usually formed. This pregroove is preferably formed directly on the substrate when injection molding or extrusion molding of a resin material such as polycarbonate. The pitch (track pitch) of the pre-groove differs depending on the CD-R type or DVD-R type. Normal CD
In the -R type, it is preferable to be formed with a track pitch having a width of 1.4 to 1.8 μm. Further, in the DVD-R type, it is preferable that the track is formed with a track pitch of 0.6 to 0.9 μm.

The depth of the pregroove is 300 to 2000 mm.
Is preferable, and the half-value width is in the range of 0.1.
It is preferably in the range of 2 to 0.9 μm. Further, by setting the depth of the pre-groove in the range of 1500 to 2000 °, the sensitivity can be improved without substantially lowering the reflectance, which is particularly advantageous for manufacturing a CD-R type optical information recording medium.

A dye recording layer is provided on a substrate. The dye recording layer contains the anionic cyanine dye represented by the formula (I) and a cationic polymer.
Dyes other than the cyanine dye represented by the formula (I) and other compounds may be used in combination. Preferred dyes used in combination in the recording layer are dicarbocyanine dyes having an indolenine nucleus or benzoindolenine nucleus for CD-R, and the corresponding carbocyanine dyes for DVD-R. . The amount of these combined dyes to be used is preferably 1/10 to 10 times, more preferably 1 to 10 times, the weight of the ion complex of the dye represented by formula (I) and the cationic polymer of the present invention. The recording layer preferably contains various compounds known as a singlet oxygen quencher in order to further improve the light resistance of the recording layer. As the singlet oxygen quencher, those described in publications such as publicly known patent specifications can be used. Specific examples thereof include JP-A-58-175693, JP-A-59-81194, JP-A-60-18387, JP-A-60-19586, and JP-A-60-195586.
19587, 60-35054, 60-361
No. 90, No. 60-36191, No. 60-44554
No. 60-44555, No. 60-44389, No. 60-44390, No. 60-54892, No. 60-
Nos. 47069 and 63-20995, JP-A-4-24-2
No. 5492, No. 1-38680 and 6-2
No. 6028, etc., German Patent 350399, and the Chemical Society of Japan, October 1992, No. 114
Examples described on page 1 and the like can be given.

The recording layer is formed by dissolving the above-mentioned dye and, if desired, a quencher, a binder and the like in a solvent to prepare a coating solution, and then applying this coating solution to the substrate surface to form a coating film. It can be performed by drying. Examples of the solvent for the dye layer coating solution include esters such as butyl acetate and cellosolve acetate; methyl ethyl ketone;
Ketones such as cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; amides such as dimethylformamide; hydrocarbons such as cyclohexane; ethers such as tetrahydrofuran, ethyl ether and dioxane; Alcohols such as propanol, isopropanol and n-butanol diacetone alcohol; fluorinated solvents such as 2,2,3,3-tetrafluoropropanol; glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and propylene glycol monomethyl ether Ethers and the like can be mentioned. The above solvents can be used alone or in combination of two or more kinds in consideration of the solubility of the dye to be used. Various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be further added to the coating solution according to the purpose.

When a binder is used, examples of the binder include natural organic high-molecular substances such as gelatin, cellulose derivatives, dextran, rosin and rubber; and hydrocarbon-based substances such as polyethylene, polypropylene, polystyrene and polyisobutylene. Resin, polyvinyl chloride, polyvinylidene chloride, vinyl resin such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resin such as polymethyl acrylate, polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, Synthetic organic polymers such as butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins can be given. When a binder is used in combination as a material for the recording layer, the amount of the binder used is generally 0.1 to 0.1 with respect to the dye.
It is in the range of 01 times to 50 times (weight ratio), preferably in the range of 0.1 times to 5 times (weight ratio). The concentration of the coating solution thus prepared is generally from 0.01 to
In the range of 10% by weight, preferably 0.1-5% by weight
In the range.

Examples of the coating method include a spray method, a spin coating method, a dipping method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method. The recording layer may be a single layer or a multilayer. The thickness of the recording layer is generally in the range from 20 to 500 nm, preferably in the range from 50 to 300 nm.

On the recording layer, a light reflecting layer is provided for the purpose of improving the reflectance at the time of reproducing information. The light-reflective substance, which is the material of the light-reflective layer, is a substance having a high reflectance with respect to laser light, and examples thereof include Mg, Se, Y, and T.
i, Zr, Hf, V, Nb, Ta, Cr, Mo, W, M
n, Re, Fe, Co, Ni, Ru, Rh, Pd, I
r, Pt, Cu, Ag, Au, Zn, Cd, Al, G
a, In, Si, Ge, Te, Pb, Po, Sn, Bi
Metal and semimetal or stainless steel. Of these, preferred are Cr,
Ni, Pt, Cu, Ag, Au, Al and stainless steel. These substances may be used alone, or in combination of two or more kinds, or may be used as an alloy. The light reflecting layer can be formed on the recording layer by, for example, vapor deposition, sputtering, or ion plating of the light reflecting substance. The thickness of the light reflecting layer is generally in the range of 10 to 300 nm,
A range of 200 nm is preferred.

On the light reflecting layer, a recording layer and the like are physically and
A protective layer is provided for the purpose of chemical protection. What
In the case of manufacturing a DVD-R type optical information recording medium,
It is not always necessary to provide a protective layer. Used for protective layer
Examples of the material to be used are SiO, SiO_Two, MgF_Two,
SnO _Two, Si_ThreeN_FourSuch as inorganic substances, thermoplastic resin, heat
List organic substances such as curable resin and UV curable resin
Can be. The protective layer is formed, for example, by extrusion of plastic.
Laminate the resulting film on the reflective layer via an adhesive.
Can be formed. Or vacuum
Provided by methods such as vapor deposition, sputtering, coating, etc.
Is also good. In the case of thermoplastic resin and thermosetting resin,
Prepared a coating solution by dissolving them in an appropriate solvent.
It is also formed by applying this coating solution and drying
can do. In the case of UV curable resin,
Alternatively, after dissolving in an appropriate solvent to prepare a coating solution,
Applying this coating liquid and irradiating it with UV light to cure it
Can also be formed. In these coating solutions
Also includes various antistatic agents, antioxidants, UV absorbers, etc.
Additives may be added according to the purpose. The thickness of the protective layer is
Generally, it is in the range of 0.1 to 100 μm. The above process
The recording layer, light reflection layer and protective layer on the substrate.
A laminated body can be manufactured.

A CD-R type optical information recording medium can be manufactured by the above steps. In addition, the DVD-R type optical information recording medium faces the two laminated bodies manufactured as described above such that the recording layers are on the inside,
It can be manufactured by joining using an adhesive. Alternatively, the laminated body manufactured as described above and a disk-shaped protective substrate having the same shape as the substrate of the laminated body are similarly faced to each other such that the recording layer is on the inside, and are bonded using an adhesive. Can be manufactured.

The optical information recording method of the present invention is performed using the above optical information recording medium, for example, as follows. First,
While rotating the optical information recording medium at a constant linear velocity (1.2 to 14 m / sec in the case of the CD format) or a constant angular velocity, recording light such as a semiconductor laser beam is irradiated from the substrate side. By this light irradiation, a cavity is formed at the interface between the recording layer and the reflective layer (the cavity is formed by deforming the recording layer or the reflective layer, or by deforming both layers),
It is considered that information is recorded when the substrate is overlaid and deformed, or when the refractive index changes due to discoloration of the recording layer or a change in the association state. The recording light is generally 500 n
A semiconductor laser beam having an oscillation wavelength in the range of m to 850 nm is used. In the present invention, a semiconductor laser beam having an oscillation wavelength in the range of 770 to 790 nm is used as a material suitable for CD-R.
A semiconductor laser beam having an oscillation wavelength in the range of 630 to 680 nm is used as a material suitable for DR. Preferred is a red laser beam having an oscillation wavelength in the range of 635-645 nm. The reproduction of the information recorded as described above can be performed by irradiating the semiconductor laser light from the substrate side while rotating the optical information recording medium at the same constant linear speed as above, and detecting the reflected light. it can.

[0064]

EXAMPLES Examples of the present invention will be described below together with comparative examples. However, these examples do not limit the present invention. The combined dyes and dye compounds for comparative examples used in the examples are shown below.

[0065]

Embedded image

[0066]

Embedded image

Example 1 To a cyanine dye compound D-1, 10% by weight of a cyanine dye compound (combination of an anionic cyanine dye and a cationic polymer) 2 in Table 1 corresponding to 10% by weight was added. It was dissolved in 3,3-tetrafluoropropanol to obtain a coating liquid for forming a recording layer. A polycarbonate substrate (diameter: 120 mm, thickness) having a spiral pre-groove (track pitch: 0.8 μm, groove width: 0.4 μm, groove depth: 0.15 μm) formed on its surface by injection molding : 0.6
mm) on the pre-groove side surface by spin coating to form a recording layer (thickness (within the groove): about 200 n).
m) was formed.

Au was sputtered on the recording layer to form a light reflecting layer having a thickness of about 100 nm, and a laminated body having the recording layer and the light reflecting layer provided in this order on the substrate was prepared. Separately, a transparent polycarbonate substrate (disk-shaped protective substrate)
(Diameter: 120 mm, thickness: 0.6 mm) was prepared.
Then, the laminate obtained above and the disc-shaped protective substrate were bonded together (thickness: 1.2 mm) using an adhesive (manufactured by Three Bond) so that the recording layer was on the inside. Through the above steps, a DVD-R type optical information recording medium according to the present invention was obtained.

Example 2 A DVD-R according to the present invention was prepared in the same manner as in Example 1 except that cyanine dye compound 6 shown in Table 1 was used in the same amount in place of cyanine dye compound 2. Type optical information recording medium was obtained.

Comparative Example 1 In Example 1, the same amount of the cyanine dye compound (compound C-1) in which a monovalent anion was combined with a monovalent cation component of the cyanine dye instead of the cyanine dye compound 2 was used. A DVD-R optical information recording medium for comparison was obtained in the same manner as in Example 1 except for using the optical information recording medium.

Comparative Example 2 An optical information recording medium for comparison (DVD-ROM) was prepared in the same manner as in Example 1 except that the same amount of the cyanine dye compound (Compound C-2) was used as in Comparative Example 1.
R) was obtained.

[Evaluation as Optical Information Recording Medium] Semiconductor laser light having a wavelength of 635 nm was condensed on the obtained optical information recording medium with a lens having an NA of 0.6, and a linear velocity of 3.68 m / s was obtained.
Recording a signal at the modulation frequency 4 mH _Z, were measured C / N. Further, the optical information recording medium is kept at 80 ° C. and 90% RH for 48 hours.
After storing for a time, C / N was measured in the same manner. Table 3 shows the obtained evaluation results.

[0073]

[Table 3]

From the results in Table 2 above, it can be seen that a DV having a recording layer containing the cyanine dye compound according to the present invention in which a cationic polymer and an anionic cyanine dye were combined.
DR (Examples 1 and 2) is a DVD having a recording layer containing a cyanine dye having no cationic polymer part.
It turns out that it has high storage stability compared with R (Comparative Examples 1 and 2).

[0075]

According to the present invention, an optical information recording medium having excellent storage stability and high C / N can be obtained by using a cyanine dye compound obtained by combining an anionic cyanine dye and a cationic polymer. Can be. In particular, even when laser light in the visible region is used, there is no decrease in C / N, and thus it can be said that the cyanine dye compound is advantageous for DVD-R. Even when the specific cyanine dye compound according to the present invention is applied to a CD-R, it can be advantageously used for improving storage stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07D 409/14 C07D 409/14 487/04 144 487/04 144 F term (Reference) 2H111 EA03 EA12 EA22 EA33 FA01 FA12 FA35 FA39 FB43 FB50 4C050 AA01 AA07 BB05 CC08 EE04 FF02 GG01 HH04 4C063 AA01 AA05 BB01 BB03 CC52 CC92 DD06 DD26 EE10 4C204 BB05 CB03 CB13 DB03 DB13 DB16 DB30 EB03 FB15 GB01 GB30 5D

Claims (10)

[Claims] 1. A heat mode optical information recording medium having a recording layer on a substrate on which information can be recorded by irradiating a laser beam, wherein the recording layer comprises a cationic polymer component and the following formula ( An optical information recording medium comprising an anionic cyanine dye component represented by I). Embedded image [Wherein, DYE ⁺ represents a monovalent cyanine dye cation, and n represents an integer of 1 or more. ] 2. The optical information recording medium according to claim 1, wherein the cyanine dye cation is represented by the following formula (II). Embedded image [Wherein, Za and Zb each independently represent an atomic group necessary for completing a 5- or 6-membered nitrogen-containing heterocyclic ring,
R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. L
¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent a substituted or unsubstituted methine group, and when there is a substituent on L ^{1 to} L ⁵ , they are linked to each other to form a ring. May be. j is 0,
Represents 1 or 2, and k represents 0 or 1. ] 3. The optical information recording medium according to claim 1, wherein the cyanine dye cation is represented by the following formula (IIA). Embedded image [Wherein, Z ¹ and Z ² each independently represent a group of atoms necessary to complete an indolenine nucleus or a benzoindolenine nucleus, and R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group. R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group; L ¹ , L ² , L ³ , L ⁴ and L ⁵ each independently represent an alkyl group; It independently represents a substituted or unsubstituted methine group, and when there is a substituent on L ^{1 to} L ⁵ , they may be linked to each other to form a ring. j represents 0, 1 or 2, and k represents 0 or 1. ] 4. The optical information recording medium according to claim 1, wherein a light reflection layer is provided on the recording layer. 5. The method according to claim 1, wherein the substrate has a track pitch of 0.6 μm.
It has a pregroove of not less than 0.9 μm and not more than 0.9 μm in thickness.
5. The optical information recording medium according to claim 1, wherein the optical information recording medium is a transparent disk of 6 ± 0.1 mm and a recording layer is provided on a surface on a side where the pregroove is formed. 6. A substrate having a track pitch of 0.6 μm.
Having a pregroove of at least 0.9 μm and a diameter of 1
A transparent disk having a thickness of 20 ± 0.3 mm and a thickness of 0.6 ± 0.1 mm, and two laminates each having the recording layer provided on a side of the substrate on which a pre-groove is formed, each 1.2 ± 0.2 thickness joined so that the recording layer is on the inside
The optical information recording medium according to any one of claims 1 to 5, wherein 7. The apparatus according to claim 1, wherein the substrate has a track pitch of 0.6 μm.
Having a pregroove of at least 0.9 μm and a diameter of 1
A transparent disc having a thickness of 0.6 ± 0.1 mm and a thickness of 0.6 ± 0.1 mm, wherein the recording layer is provided on a side of the substrate on which a pre-groove is formed; The optical information recording medium according to any one of claims 1 to 5, wherein a transparent disk-shaped protective substrate having the same shape is joined so that the recording layer of the laminate is on the inside, and has a thickness of 1.2 ± 0.2 mm. 8. A substrate having a track pitch of 1.4 μm.
It has a pre-groove of not less than 1.8 μm and a thickness of 1.
5. The optical information recording medium according to claim 1, wherein the optical information recording medium is a transparent disk of 2 ± 0.2 mm and a recording layer is provided on a surface on a side where the pregroove is formed. 9. An information recording method for recording information by irradiating the optical information recording medium according to claim 1 with a laser having a wavelength of 630 nm to 680 nm. 10. The optical information recording medium according to claim 1, wherein the wavelength is 750 nm or more and 800 or more.
An information recording method in which information is recorded by irradiating a laser of nm or less.