JP2003260877A - Optical recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording medium which is applicable to a high-density optical disc system using a semiconductor laser having an oscillation wavelength in a short wavelength range rather than in the conventional wavelength range and shows outstanding light resistance and shelf stability, and also provide a recording medium for a CD-R medium which can be recorded and regenerated using a currently available system and besides, can be only regenerated in a next-generation high-density optical disc system. <P>SOLUTION: At least one kind of chemical compound represented by formula (1) or the like or the chemical compound and an organic coloring matter having a maximum absorption wavelength in the range of 680 to 750 nm are added to a recording layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium, and in particular, by irradiating a light beam, an optical change such as transmittance and reflectance of a recording material is caused,
The present invention relates to an optical recording medium capable of recording / reproducing information and additionally recording.

[0002]

2. Description of the Related Art The current write-once optical disc system (WO
RM, CD-R), the oscillation wavelength of the laser used is 770
nm to 790 nm, the recording medium records at the above wavelength,
It is configured to be playable. In the future, it is essential to increase the capacity of recording media as the amount of information increases. Therefore, it is easily expected that the laser wavelength used for recording and reproduction will be shortened inevitably. As a write-once optical disc for data, many proposals have been made using a cyanine dye or a phthalocyanine dye as a recording material (for example, a disc using a cyanine dye as a recording material is disclosed in JP-A-57-82093). JP-A-58-56892, JP-A-58-112790,
JP-A-58-114989, JP-A-59-85791
No. 60-83236, 60-8984.
No. 2, JP-A No. 61-25886, and those using a phthalocyanine dye as a recording material, JP-A No. 61-150243 and JP-A No. 61-177287.
No. 6/154888 / 61-246
091, JP-A-62-39286, JP-A-63-3
No. 7791, JP-A-63-39888, etc.), but a recording material which is excellent in light resistance and storage stability and which can be recorded and reproduced by an optical pickup using a laser of 700 nm or less has not yet been developed. The current situation is that it has not been done.

The current CD-R disc system is also configured to be capable of recording and reproducing at the oscillation wavelength of the laser used, that is, 770 nm to 790 nm. This system is also required to have a large capacity and a short recording / reproducing wavelength, similarly to the above. In this regard, current CDs and CD-ROMs are
Al is coated on the unevenness of the substrate itself.
Since the wavelength dependency of the reflectance of the is small, it is possible to reproduce even if the laser wavelength is shortened in the future. However,
The CD-R uses a dye having a maximum absorption wavelength in the recording layer of 680 nm to 750 nm, and is set to obtain a high reflectance in the range of 770 nm to 790 nm due to its optical constant and film thickness. Since the reflectance is extremely low, it cannot cope with the shortening of the laser wavelength, and the information recorded and reproduced by the current CD-R system cannot be reproduced by the future system. So far CD
As -R, many proposals have been made using a cyanine dye / metal reflection layer, a phthalocyanine dye / metal reflection layer, an azo metal chelate dye / metal reflection layer, or the like as a recording material (for example, a cyanine dye / metal reflection layer is used). The materials used as recording materials are those disclosed in JP-A-1-159842, JP-A-2-42652, JP-A-2-13656, JP-A-2-168446, etc., which use a phthalocyanine dye as a recording material. Japanese Patent Application Laid-Open No. 1-1765
85, JP-A-3-215466, JP-A-4-113.
886, JP-A-4-226390, JP-A-5-12
72, JP-A-5-171052, and JP-A-5-116.
456, JP-A-5-69860, and JP-A-5-139.
No. 044, JP-A-4-46186, and those using an azo metal chelate dye as a recording material.
JP-A-4-141489 and JP-A-4-361088
No. 5,271,580, etc.), but no solution to such a point has been found yet.

[0004]

Therefore, the present invention has been made in view of the above situation, and is a high density optical disc using a semiconductor laser having an oscillation wavelength in a shorter wavelength than the conventional system. A CD-recordable material that can be applied to a system and is excellent in light resistance and storage stability for an optical recording medium, and that can be recorded and reproduced in the current system and can be reproduced in a next-generation high-density optical disc system. It is an object of the present invention to provide a recording material for R medium.

[0005]

As a result of intensive investigations by the present inventors, a high density using a semiconductor laser having an oscillation wavelength of 700 nm or less is provided by providing a recording layer containing a dye having a specific structure as a main component. It has been found that it can be applied to optical disk systems, and by using this dye mixed with an organic dye currently used as a recording material for CD-R, a high reflectance can be obtained even in a wavelength range of 700 nm or less. It was found that the above was possible, and the present invention was completed.

[0006] That is, according to the present invention, firstly, a recording layer is provided on a substrate directly or via an undercoat layer, and if necessary, a reflection layer and a protective layer are provided on the recording layer. In a recording medium, there is provided an optical recording medium characterized in that the recording layer contains at least one compound represented by the following general formula (I).

[Chemical 2] [In the formula, M, X¹~ X^FourAnd X^Five~ X⁸Are respectively
Represents something. M: 2 hydrogen atoms or oxygen atoms
Or divalent, trivalent or 4 which may have a halogen atom.
A valent metal atom, or a substituted or unsubstituted alkyl group,
Aryl group, alkoxy group, aryloxy group,-(O
PR¹R²) P group, (-OPOR³R^Four) P group,-(OSiR
^FiveR⁶R⁷) P group,-(OCOR⁸) P group,-(OR⁹) P group,
-(OCOCOOR^Ten) P group,-(OCOCOR)¹¹) P group
Or- (OCONR ¹²R¹³) Gold that may have p groups
Genus atom, R¹~ R¹³: Independently hydrogen atom, substitution
Or unsubstituted monovalent aliphatic hydrocarbon group or substituted or
Is an unsubstituted monovalent aromatic hydrocarbon group, p: 0 to 2
Number, X¹~ X^Four, X^Five~ X⁸: Independently hydrogen atom,
Rogen atom, cyano group, substituted or unsubstituted straight chain
Or branched alkyl group, alkylalkoxy group, substituted
Or unsubstituted alkoxy group, carboxylic acid ester group,
Substituted or unsubstituted aryl group, substituted or unsubstituted
Aryloxy groups, substituted or unsubstituted alkyl groups
Group, substituted or unsubstituted arylthio group, substituted or not
Or an unsubstituted benzyl group, a substituted or unsubstituted benzyl group
Or a substituted or unsubstituted benzylthio group or
Heterocyclic residue. Secondly, in the general formula (I), X
¹~ X^FourAre each independently a hydrogen atom or substituted or unplaced
A substituted linear or branched alkyl group, X^Five~ X⁸Is that
Independently hydrogen atom, alkoxy group or halogen atom
(However, X¹~ X⁸Is not all hydrogen atoms
The optical recording medium according to the first aspect is provided.
It Thirdly, in the general formula (I), X¹~ X^FourGazo
Each independently a hydrogen atom or a substituted or unsubstituted straight chain
Or a branched alkyl group, X^Five~ X⁸Each independently
Hydrogen atom or halogen atom (provided that X¹~ X⁸All of
It is never a hydrogen atom)
An optical recording medium is provided. Fourthly, in the general formula (I)
By the way, X¹~ X^FourAre each independently a hydrogen atom,
Or unsubstituted linear or branched alkyl group, alkyl
An alkoxy group or an alkoxyl group, X^Five~ X⁸Is a substituent
Y¹And Y²A phenyl group having¹, Y²Are each
Straight chain that may be independently substituted with hydrogen atom or halogen atom
Or branched alkyl group, alkylalkoxy group,
Ali which may be substituted with a rucoxyl group or a halogen atom
The optical recording medium according to the first aspect is
It Fifth, in the general formula (I), X¹~ X^FourIs
Ano group, X^Five~ X⁸Is a substituted or unsubstituted straight chain or
The optical recording medium described in the first above is a variety of alkyl groups.
Provided. Sixth, in the general formula (I), X¹
~ X^FourIs a cyano group, X^Five~ X⁸Is a substituent Z¹~ Z^Five, Z¹'
~ Z^Five', Z¹'' ~ Z^Five'', Z¹'' '~ Z^FivePheny with '' '
At least one of the substituents is a fluorine atom or a fluorine group.
It is an alkyl group or an alkoxyl group containing elementary atoms.
There is provided the optical recording medium described in the above first. Seventh,
In the general formula (I), X¹~ X^FourIs a cyano group, X
^Five~ X⁸Is a substituted or unsubstituted aryl group
An optical recording medium according to the first aspect is provided. Eighth, the general
In formula (I), X¹~ X^FourEach independently hydrogen source
Child, substituted or unsubstituted linear or branched alkyl
By X^Five~ X⁸Is a hydrogen atom, an alkyl group or a halogen atom
There is provided an optical recording medium as described above, which is a child.
Ninth, the recording layer is a compound represented by the general formula (I).
Absorption of at least one of the objects and 680 nm to 750 nm
It is characterized by containing an organic dye having a wavelength
The optical recording medium according to any one of the above first to eighth
Provided. Tenth, it is most suitable for the 680 nm to 750 nm.
Cyanine of pentamethine is an organic dye having a large absorption wavelength.
Dyes, phthalocyanine dyes and azo metal chelate dyes
The optical recording medium described in the ninth item is at least one kind.
Provided. Eleventh, the recording layer has wavelengths of 630 to 72.
The above-mentioned first which is recorded by a 0 nm laser beam.
An optical recording medium according to any one of items 1 to 10 is provided.
It Twelfth, the reflective layer is made of aluminum or gold.
The optical recording medium according to any one of the above first to eleventh
Provided. Thirteenth, the protective layer is an ultraviolet curable resin
The optical recording as described in any one of the above 1st to 12th
Media is provided.

The optical recording medium of the present invention has the above general formula (I).
Since the recording layer containing at least one of the compounds shown in 1) is provided, recording and reproduction can be performed with a laser beam in a wavelength range of 700 nm or less, and light resistance and storage stability are excellent. In the embodiment,
680 to 750 and at least one compound represented by
Since the recording layer made of a mixture with the organic dye having the maximum absorption wavelength in nm is provided, the CD-R in the current system is
It can be used as a medium, and even if it becomes a next-generation high-density optical disc system, it becomes possible to reproduce the described information.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The optical recording medium of the present invention is characterized in that the recording layer contains at least one compound represented by the general formula (I).

[Chemical 3]

First, the above general formula (I) used in the present invention is used.
The compound represented by will be described. The general formula (I)
In, M is two hydrogen atoms, or an oxygen atom, or
Divalent, trivalent or tetravalent optionally having a halogen atom
Metal atom, or substituted or unsubstituted alkyl group, ari
Group, alkoxy group, aryloxy group,-(OPR
¹R²) P group, (-OPOR³R^Four) P group,-(OSiR^FiveR⁶
R⁷) P group,-(OCOR⁸) P group,-(OR⁹) P group, −
(OCOCOOR^Ten) P group,-(OCOCOR)¹¹) P group
Or- (OCONR¹²R¹³) Metals that may have p groups
Represents an atom. R ¹~ R¹³Are each independently a hydrogen atom,
Substituted or unsubstituted monovalent aliphatic hydrocarbon group or substituted
Or represents an unsubstituted monovalent aromatic hydrocarbon group, p
Represents an integer of 0 to 2. X¹~ X^FourAnd X^Five~ X⁸Is it
Independently hydrogen atom, halogen atom, cyano group, substitution
Or unsubstituted linear or branched alkyl group, alkyl group
Alkoxy group, substituted or unsubstituted alkoxy group,
Carboxyl ester group, substituted or unsubstituted aryl
Group, substituted or unsubstituted aryloxy group, substituted or not
Or an unsubstituted alkylthio group, a substituted or unsubstituted
Reelthio group, substituted or unsubstituted benzyl group, substituted
Or, an unsubstituted benzyloxy group, a substituted or unsubstituted
Represents a substituted benzylthio group or a heterocyclic residue.

In the present invention, X ¹ ≠ X ⁵ , X ² ≠ X ⁶ , X
^{When 3} ≠ X ⁷ and X ⁴ ≠ X ⁸ , the symmetry of the molecule is lowered and the solubility is excellent, the coating type recording layer can be formed, and each of the following (A) to (D) When there are four isomers and they are a mixture thereof, it is advantageous when finely adjusting the characteristics such as the absorption wavelength, and the recording power margin and the like when the film is thinned can be expanded.

[0011]

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

In the general formula (I), specific examples of the alkyl group of X ^{1 to} X ⁴ and X ^{5 to} X ⁸ (including an alkoxy group and an alkyl moiety in the alkylalkoxy group) are as follows. Can be mentioned. In addition, these alkyl groups may be substituted with a substituent such as a halogen atom. Methyl group,
Ethyl group, n-propyl group, n-butyl group, isobutyl group, n-pentyl group, neopentyl group, isoamyl group,
2-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group,
3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3
-Ethylhexyl group, n-nonyl group, n-decyl group, n
-Primary alkyl group such as dodecyl group; isopropyl group, s
ec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group, 1-methylheptyl group, 1-ethylbutyl group, 1,3-dimethylbutyl group, 1,2-dimethylbutyl group , 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2
-Methylpropyl group, 1-ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1- Isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-
Secondary alkyl group such as methylbutyl group; tert-butyl group, tert-hexyl group, tert-amyl group, te
Tertiary alkyl groups such as rt-octyl group; cyclohexyl group, 4-methylcyclohexyl group, 4-ethylcyclohexyl group, 4-tert-butylcyclohexyl group, 4
A cycloalkyl group such as a-(2-ethylhexyl) cyclohexyl group, a bornyl group, an isobornyl group, an adamantane group and the like. Examples of the unsaturated alkyl group include ethylene group, propylene group, butylene group, hexene group, octene group, dodecene group, cyclohexene group and butylhexene group.

Specific examples of the substituted or unsubstituted aryl group and the aryl moiety of the substituted or unsubstituted aryloxy group include a phenyl group, a methylphenyl group,
Examples include dimethylphenyl group, trimethylphenyl group, ethylphenyl group, tert-butylphenyl group, butylphenyl group, nonylphenyl group, methoxyphenyl group, dimethoxyphenyl group, butoxyphenyl group, naphthyl group, pyridyl group, and methylpyridyl group. To be In addition, these aryl groups may be substituted with a substituent such as a halogen atom. In addition, specific examples of the heterocyclic residue include:
A substituted or unsubstituted pyridine residue, a pyridazine residue,
Examples thereof include a pyrimidine residue, a pyrazine residue and a thiophene residue.

[0014] In the general formula (I), X ⁵ ~X ⁸ is, Y ^1, Y ² alkyl group (an alkoxy group where a phenyl group having a substituent Y ^1, Y ^2, the alkyl portions of the alkyl alkoxy group (Including), a methyl group, an ethyl group, n
-Propyl group, ns-butyl group, isobutyl group, n-pentyl group, neopentyl group, isoamyl group, 2-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3
-Methylpentyl group, 4-methylpentyl group, 2-ethylbutyl group, n-heptyl group, 2-methylhexyl group,
3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3
-Methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2-ethylhexyl group, 3-ethylhexyl group, n-nonyl group, n-decyl group, n-dodecyl group and other primary alkyl groups, isopropyl group , Sec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,
2-dimethylpropyl group, 1-methylheptyl group, 1-
Ethylbutyl group, 1,3-dimethylbutyl group, 1,2-
Dimethylbutyl group, 1-ethyl-2-methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1
-Propylbutyl group, 1-isopropyl-2-methylpropyl group, 1-ethyl-2-methylbutyl group, 1-propyl-2-methylpropyl group, 1-methylheptyl group,
1-ethylhexyl group, 1-propylpentyl group, 1-
Isopropyl pentyl group, 1-isopropyl-2-methylbutyl group, 1-isopropyl-3-methylbutyl group,
Secondary alkyl groups such as 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group, tert-butyl group, tert.
Examples thereof include tertiary alkyl groups such as -hexyl group, tert-amyl group and tert-octyl group, and these alkyl groups may be substituted with a substituent such as a halogen atom. As the aryl group, phenyl group, methylphenyl group, dimethylphenyl group, ethylphenyl group, t
Examples thereof include an ert-butylphenyl group, a butylphenyl group, a methoxyphenyl group, a dimethoxyphenyl group and a butoxyphenyl group. These aryl groups may be substituted with a substituent such as a halogen atom.

In the general formula (I), X^Five~ X⁸But
Substituent Z¹~ Z^Five, Z¹'~ Z^Five', Z¹'' ~ Z^Five'', Z¹'' '~
Z^FiveWhen it is a phenyl group having "", Z¹~ Z^Five, Z¹'
~ Z ^Five', Z¹'' ~ Z^Five'', Z¹'' '~ Z^Five'' 'Is for each
Vertically replace hydrogen atom, halogen atom, halogen atom
Is an unsubstituted linear or branched alkyl group or alkoxy
Group, a halogen atom-substituted or unsubstituted alkoxy group,
Halogen atom-substituted or unsubstituted aryl group, alkyl group
Luamino group, alkylthio group, alkylsilyl group, hydroxy
Represents a group, a nitro group or a nitrile group.

Z ^{1 to} Z ⁵ , Z ¹ 'to Z ⁵ ' in the general formula (I),
As an alkyl group (including an alkyl moiety in an alkoxy group, an alkylalkoxy group, an alkylamino group, an alkylthio group, an alkylsilyl group) of Z ¹ ″ to Z ⁵ ″ and Z ¹ ′ ″ to Z ⁵ ′ ″ Is a methyl group, an ethyl group, an n-propyl group,
n-butyl group, isobutyl group, n-pentyl group, neopentyl group, isoamyl group, 2-methylbutyl group, n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 2-ethylbutyl Group, n-
Heptyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group,
2-ethylpentyl group, 3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 2
-Primary alkyl groups such as ethylhexyl group, 3-ethylhexyl group, n-nonyl group, n-decyl group, isopropyl group, sec-butyl group, 1-ethylpropyl group, 1-methylbutyl group, 1,2-dimethylpropyl group Group, 1-methylheptyl group, 1-ethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 1-ethyl-2
-Methylpropyl group, 1-methylhexyl group, 1-ethylheptyl group, 1-propylbutyl group, 1-isopropyl-2-methylpropyl group, 1-ethyl-2-methylbutyl group, 1-isopropylbutyl group, 1- Methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-isopropylpentyl group, 1-isopropyl-
Secondary alkyl groups such as 2-methylbutyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-isobutyl-3-methylbutyl group, tert.
Examples thereof include tertiary alkyl groups such as -butyl group, tert-amyl group and tert-heptyl group, and these alkyl groups may be substituted with a substituent such as a halogen atom.
As the aryl group, a phenyl group, a methylphenyl group, a dimethylphenyl group, a trimethylphenyl group, an ethylphenyl group, a tert-butylphenyl group, a di (te
rt-butyl) phenyl group, butylphenyl group, methoxyphenyl group, dimethoxyphenyl group, trimethoxyphenyl group, butoxyphenyl group, and the like, and these aryl groups may be substituted with a substituent such as a halogen atom. Good.

In the general formula (I), X ^{1 to} X ⁴ and X ⁵ to
As the substituted aryl group for X ⁸ , each aryl group includes a methyl group, an ethyl group, a butyl group, an isobutyl group, an n-pentyl group, a neopentyl group, an isopropyl group, a sec-butyl group, a 1-ethylpropyl group, and a 1-methylbutyl group. Base, t
ert-butyl group, tert-hexyl group, tert-
Alkyl groups such as amyl groups and similar alkyl-containing alkoxy groups, trifluoromethyl groups, other fluorine-substituted alkyl groups, fluorine-substituted alkoxy groups, halogen atoms, nitro groups, cyano groups, hydroxy groups, etc. good. Further, alkyl of the carboxylic acid ester group is methyl,
It is synonymous with those specifically mentioned for the above alkyl group such as ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl and the like. When X ^{5 to} X ⁸ are halogen atoms, preferred is a bromine atom or a chlorine atom.

In the general formula (I), specific examples of M include hydrogen atom; Ca, Mg, Zu, Cu, Ni, Pd, Fe,
Divalent metal such as Pb, Co, Pt, Cd, Ru; A
l, In, Fe, Ga, Tl, Mn and other trivalent metal halides, hydroxyl compounds, alkoxy compounds, trialkylsiloxy compounds, etc .; and Si, Ti, Sn, C
Examples thereof include halides, hydroxyl compounds, alkoxy compounds, trialkylsiloxy compounds and oxides of tetravalent metals such as r, Ga, Sn, Mn, Zr and V. Also,
In the definitions of R ^{1 to} R ¹³ , the monovalent aliphatic hydrocarbon group is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, or a te group.
rt-butyl group, amyl group, hexyl group, octyl group,
Examples thereof include alkyl groups such as decyl group, dodecyl group and octadecyl group, and alkenyl groups such as vinyl group, allyl group, isopropenyl group, 1-butenyl group, 2-butenyl group and 2-pentenyl group. Examples of the monovalent aromatic hydrocarbon group include a phenyl group and a benzyl group. Examples of the substituents include halogen atoms such as fluorine, chlorine and bromine, carbon trifluoride groups, cyano groups and ester groups.

Particularly, in the general formula (I), when X ^{5 to} X ⁸ are halogen atoms, the absorption wavelength becomes longer, which is very suitable for controlling the wavelength of the recording material.
M in the formula when it is around 5 nm is Pd, Ni, Co,
Most preferred are Pt, Cu, Zn and VO. As the decomposition temperature decreases, thermal decomposition rapidly occurs, the shape of the recording pit becomes good, and the recording / reproducing characteristics are excellent. However, when X ^{5 to} X ⁸ are replaced with halogen, the solubility is reduced, and it becomes difficult to form the recording layer by the solvent coating method. Therefore, it is not possible to form a recording layer by mixing a halogen-substituted compound and a halogen-unsubstituted compound.
It is an effective means. Furthermore, by using a mixture of a halogen-substituted compound and a non-substituted compound, the margin of the recording / reproducing wavelength can be expanded. In this case, the mixing ratio of the halogen-substituted compound and the non-substituted compound can be selected in the range of 1-99: 99-1 and preferably in the range of 20-80: 80-20. When the halogen substitution product alone is used as the recording layer, X
Solubility must be improved by ^{1 to} X ⁴ , in which case
When the alkyl group has 5 or more carbon atoms, a recording layer can be formed on an injection-molded substrate by a solvent coating method. Further, the halogen atom of X ^{5 to} X ⁸ is most preferably a bromine atom in view of the production method of the compound and recording characteristics.

The above can be summarized as follows.
Of the compounds of formula (I)¹~ X⁸
In each substituent of¹~ X^FourIs replaced or not
A linear or branched alkyl group, X^Five~ X⁸Is hydrogen or halo
What is a Gen atom, X¹~ X^FourIs replaced or not
A linear or branched alkyl group having 5 or more carbon atoms, X^Five~ X⁸
Is hydrogen or a halogen atom, X¹~ X^FourReplaced by
Or an unsubstituted linear or branched alkyl group, X^Five~ X⁸
Is a substituted or unsubstituted aryl group, X¹~
X^FourIs a cyano group, X^Five~ X⁸Is a substituted or unsubstituted
Reel-based, X¹~ X^FourIs a cyano group, X^Five~ X⁸
Is a substituted or unsubstituted linear or branched alkyl group
Things, X¹~ X^FourIs a halogen atom and X^Five~ X⁸Replaced by
Or an unsubstituted linear or branched alkoxy group or aryl
Those which are ruoxy groups, X¹~ X^FourIs replaced or not replaced
An aryl group of X^Five~ X⁸Is a carboxylic acid ester group
The combination of the respective substituents is particularly preferable.
Yes. In addition, X of the compound of general formula (I)¹~ X⁸Substituent of
Is X¹~ X^FourX^Five~ X⁸And X ^Five~ X⁸X¹~ X^FourRead as
You can also get it.

Specific examples of the compound represented by the general formula (I) include those shown in Table 1. In Table 1, the isomers are not described, but for example, compound No. 4 actually has four isomers as described above.

[0022]

[Table 1]

In the recording layer, as described above, a mixture containing at least one compound represented by the general formula (I) and an organic dye having a maximum absorption wavelength at 680 to 750 nm is a main component. As a result, the CD-R recording medium can be recorded and reproduced by the current system and can be reproduced only by the next-generation system. In this case, as the dye having the maximum absorption wavelength at 680 to 750 nm, pentamethine cyanine dye, phthalocyanine dye and azo metal chelate dye are preferable.

Preferred examples of pentamethine cyanine dyes include those represented by the following general formula (II).

[Chemical 8] In the formula, R ²¹ and R ²² are each an alkyl group having 1 to 3 carbon atoms, R ²³ ,
R ²⁴ is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, X
Represents an acid anion. The aromatic ring may be condensed with another aromatic ring, and may be substituted with an alkyl group, a halogen atom, an alkoxy group or an acyl group.

Preferred examples of the phthalocyanine dye include those represented by the following general formula (III) or (IV).

[Chemical 9] In the formula, M ¹ is Ni, Pd, Cu, Zn, Co, Mn, F
e, TiO or VO, X ^{11 to} X ¹⁴ are each independently —OR or —SR at the substitution position α-position, and R is an optionally substituted linear, branched or alicyclic group having 3 to 12 carbon atoms. It represents an alkyl group or an aryl group which may also be substituted. Substituents on the benzene ring other than X ^{11 to} X ¹⁴ are hydrogen atoms or halogen atoms.

[0026]

[Chemical 10] In the formula, M ² is Si, Ge, In, or Sn, and is X ¹⁵ to
X ¹⁸ are each independently -OR or -SR at the substitution position α position.
R is a straight chain having 3 to 12 carbon atoms which may be substituted,
A branched or alicyclic alkyl group or an aryl group which may also be substituted, Y ¹ and Y ² are —OSiR ²⁵ R ²⁶ R
²⁷ , -OCOR ²⁵ R ²⁶ R ²⁷ , or -OPOR ²⁵ R ²⁶ R ²⁷
And R ^{25 to} R ²⁷ each independently have 1 to 10 carbon atoms.
Represents an alkyl group or an aryl group. Substituents on the benzene ring other than X ^{9 to} X ¹² are hydrogen atoms or halogen atoms.

Preferred examples of the azo metal chelate dye include one or more azo metal chelate compounds of an azo compound represented by the following general formula (V) and a metal, and the metal is preferable. Examples include Ni, Pt,
Pd, Co, Cu, Zn etc. are mentioned.

[Chemical 11] In the formula, A represents a residue which forms a heterocyclic ring together with the carbon atom and nitrogen atom to which it is bonded, and B represents an aromatic ring together with the two carbon atoms to which it is bonded. Or represents a residue forming a heterocycle, and X represents a group having active hydrogen.

When the at least one dye represented by the general formula (I) of the present invention and the at least one dye represented by the general formulas (II) to (V) are used in combination, the weight composition ratio is The dye of the present invention / [the dye of (III) to (VI)] = 10 /
100-90 / 100, preferably 40 / 100-20
/ 100. When both dyes are used in combination, the thickness of the recording layer is 500Å to 5 μm, preferably 1000Å to 5 μm.
It is 000Å.

Next, the structure of the recording medium of the present invention will be described. FIG. 1 is a diagram showing an example of a layer structure applicable to the recording medium of the present invention, which is an example of a write-once optical disc. The recording layer 2 is formed on the substrate 1 through the undercoat layer 3 if necessary.
And a protective layer 4 is further provided if necessary. Further, a hard coat layer can be provided under the substrate 1 as needed. FIG. 2 is a diagram showing another type of layer structure example applicable to the recording medium of the present invention, which is an example of a CD-R medium. A reflective layer 6 is formed on the recording layer 2 having the structure shown in FIG.
Is provided. FIG. 3 is a diagram showing another example of the layer structure of another type applicable to the recording medium of the present invention, in which the adhesive layer 8 and the protective substrate 7 are provided on the protective layer 4 having the structure of FIG. . The recording medium of the present invention may have an air sandwich structure in which the recording layer (organic thin film layer) having the structure shown in FIGS. 1 and 2 is placed inside and sealed with another substrate through a space. You may make it the laminated structure adhere | attached through the protective layer.

Next, the required characteristics of the constituent layers and the constituent materials thereof will be described. 1) Substrate As a necessary characteristic of the substrate, when recording / reproducing is performed from the substrate side, it must be transparent to the laser light used, but it is not necessary to be transparent when recording / reproducing is performed from the recording layer side. As the substrate material, for example, polyester, acrylic resin, polyamide, polycarbonate resin, polyolefin resin, phenol resin, epoxy resin, plastic such as polyimide, glass, ceramic or metal can be used. In addition, a guide groove or a guide pit for tracking and a preformat such as an address signal may be formed on the surface of the substrate.

2) Recording Layer The recording layer is capable of recording some information by causing some kind of optical change by irradiation with laser light, and
In this recording layer, at least one of the compounds represented by the general formula (I), and optionally the general formula (II) to
It is necessary to contain at least one of the dyes represented by (V). Further, these dyes can be used as a mixture or layered with other organic dyes and metals or metal compounds in order to improve optical characteristics, recording sensitivity and signal characteristics. Other organic dyes in this case include polymethine dyes, naphthalocyanine dyes, phthalocyanine dyes, squarylium dyes, croconium dyes, pyrylium dyes, naphthoquinone dyes, anthraquinone (indanthrene) dyes, xanthene dyes, triphenylmethane dyes, azulene dyes. , Tetrahydrocholine-based dyes, phenanthrene-based dyes, triphenothiazine-based dyes, and metal complex compounds. Examples of metals and metal compounds include In, Te, Bi,
Se, Sb, Ge, Sn, Al, Be, TeO ₂ , Sn
O, As, Cd and the like can be used, and each can be used in the form of dispersion mixing or lamination. Further, various materials such as ionomer resins, polyamide resins, vinyl resins, natural polymers, silicones, liquid rubbers, or silane coupling agents may be dispersed and mixed in the above dye, and the characteristics thereof may be mixed. For the purpose of improvement, it can be used together with a stabilizer (for example, a transition metal complex), a dispersant, a flame retardant, a lubricant, an antistatic agent, a surfactant, a plasticizer and the like.

The recording layer is formed by vapor deposition, sputtering, C
It can be done by conventional means such as VD or solvent coating. When the coating method is used, the dye or the like is dissolved in an organic solvent, spraying, roller coating,
It can be carried out by a conventional coating method such as dipping or spin coating. As the organic solvent to be used, generally, alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, amides such as N, N-dimethylacetamide and N, N-dimethylformamide, sulfoxides such as dimethyl sulfoxide. Ethers such as tetrahydrofuran, dioxane, diethyl ether, ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aliphatic halogenated carbons such as chloroform, methylene chloride, dichloroethane, carbon tetrachloride and trichloroethane,
Aromatic compounds such as benzene, xylene, monochlorobenzene, dichlorobenzene, or methoxyethanol,
Examples thereof include cellosolves such as ethoxyethanol, hydrocarbons such as hexane, pentane, cyclohexane and methylcyclohexane. The thickness of the recording layer is 100
Å-10 μm, preferably 200 Å-2000 Å are suitable.

3) Undercoat layer The undercoat layer has an improved adhesive property, a barrier against water or gas, an improved storage stability of the recording layer, an improved reflectance, protection of the substrate from a solvent, a guide groove, and a guide. It is used to form pits and preformats. For the purpose of, it is possible to use various polymer compounds such as ionomer resins, polyamides, vinyl resins, natural resins, natural polymers, silicones, liquid rubbers, and silane coupling agents.
For the purpose of and, in addition to the above polymer materials, inorganic compounds such as SiO ₂ , MgF ₂ , SiO, TiO ₂ , Z
nO, TiN, SiN, etc., and further metal or semimetal, for example, Zn, Cu, Ni, Cr, Ge, Se, A
u, Ag, Al or the like can be used. For the purpose of (1), a metal such as Al, Au, Ag or the like, or an organic thin film having a metallic luster such as a methine dye or a xanthene dye can be used, and for the purpose of A curable resin, a thermosetting resin, a thermoplastic resin or the like can be used. The thickness of the undercoat layer is 0.
01 to 30 μm, preferably 0.05 to 10 μm is suitable.

4) Reflective layer For the reflective layer, a metal or a semi-metal which has a high reflectance and is resistant to corrosion can be used. Examples of materials include Au,
Ag, Al, Cr, Ni, Fe, Sn, etc. are mentioned,
Au and Al are most preferable in terms of reflectance and productivity. These metals and semimetals may be used alone or as an alloy of two or more kinds. Examples of the film forming method include vapor deposition and sputtering, and the film thickness is 50 to 5000.
Å, preferably 100 to 3000 Å.

5) Protective layer, substrate-side hard coat layer The protective layer or substrate-side hard coat layer protects the recording layer (reflective / absorptive layer) from scratches, dust, dirt, etc. It is used for the purpose of improving stability and reflectance. For these purposes, the materials shown in the undercoat layer can be used. Also,
SiO, SiO _2, etc. can be used as the inorganic material, and polymethyl acrylate, polycarbonate, epoxy resin, polystyrene, polyester resin, vinyl resin, cellulose, aliphatic hydrocarbon resin as the organic material,
A heat-softening and heat-melting resin such as natural rubber, styrene-butadiene resin, chloroprene rubber, wax, alkyd resin, drying oil and rosin can also be used. The most preferable material among the above materials is an ultraviolet curable resin having excellent productivity. The thickness of the protective layer or the hard coat layer on the substrate surface is 0.01 to 30 μm, preferably 0.05 to 10 μm.
Is appropriate.

In the present invention, the undercoat layer, the protective layer and the hard coat layer on the substrate surface are the same as in the case of the recording layer.
Stabilizers, dispersants, flame retardants, lubricants, antistatic agents, surfactants, plasticizers and the like can be added.

[0037]

The present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1 <Preparation of Optical Information Recording Medium A> A 1.2 mm thick injection-molded polycarbonate substrate having guide grooves with a depth of 1000 Å, a half value width of 0.35 μm and a track pitch of 1.0 μm was formed. The compound shown in 2 is methylcyclohexane, 2
-A solution dissolved in a mixed solution of methoxyethanol, methyl ethyl ketone, and tetrahydrofuran is applied by a spinner to form a recording layer having a thickness of 1800Å, and then a reflective layer of Au2000Å is formed by a sputtering method, and an acrylic photopolymer is further formed on the reflective layer. An optical information recording medium 1 was prepared by providing a protective layer having a thickness of 5 μm.

Comparative Example 1-1 In Example 1, compound No. Example 1 except that a compound represented by the following formula (a) was used in place of 1.
An optical information recording medium ratio 1-1 of Comparative Example 1-1 was prepared in the same manner as in.

[Chemical 12]

Comparative Example 1-2 In Example 1, compound No. Example 9 except that a compound represented by the following formula (b) was used in place of 1.
The optical information recording medium ratio of Comparative Example 1-2 as in 1-2
It was created.

[Chemical 13]

The prepared optical information recording medium 1 and the ratio 1-1,
Ratio 1-2, oscillation wavelength 635 nm, beam diameter 1.0 μm
EF while tracking using the semiconductor laser light of
The M signal was recorded (linear velocity 1.4 m / sec), and the reproduced waveform was observed (initial value). Next, light resistance test (40,000 Lu
After irradiating with x, Xe light for 50 hours, the reproduced waveform was observed (after light resistance test). The results are shown in Table 2.

[0042]

[Table 2]

Example 2 <Fabrication of Optical Information Recording Medium B> A 1.2 mm thick injection-molded polycarbonate substrate having guide grooves with a depth of 1000 Å, a half width of 0.40 μm and a track pitch of 1.1 μm was prepared. The compound represented by 3 and the compound represented by the formula (b) are mixed in a weight ratio (1: 1), and the solution is dissolved in a mixed solution of methylcyclohexane, 2-methoxyethanol, methyl ethyl ketone and tetrahydrofuran by spinner coating. Then, a recording layer having a thickness of 1700Å is formed, and then a reflective layer of Au2000Å is provided on the recording layer by a sputtering method, and further, an acrylic photopolymer is used to form 5
An optical information recording medium 2 was prepared by providing a protective layer of μm.

Comparative Example 2-1 In Example 2, the compound No. 3 was used, the compound of the formula (b) was used, and the thickness of the recording layer was adjusted to 160
The optical information recording medium ratio 2 of Comparative Example 2-1 was the same as in Example 2 except that 0Å and the thickness of the reflective layer were 2100Å.
-1 was created.

Comparative Example 2-2 The same as Comparative Example 2-1, except that the compound represented by the following formula (c) was used in place of the compound represented by the formula (b) in Comparative example 2-1. Then, an optical information recording medium ratio 2-2 of Comparative Example 2-2 was prepared.

[Chemical 14]

Comparative Example 2-3 The same as Comparative Example 2-1 except that the compound represented by the following formula (d) was used in place of the compound represented by the formula (b) in Comparative example 2-1. Then, an optical information recording medium ratio 2-3 of Comparative Example 2-3 was prepared.

[Chemical 15]

The prepared optical information recording medium 2 and the ratios 2-1 to 2-1
2-3, using a semiconductor laser light with an oscillation wavelength of 780 nm and a beam diameter of 1.6 μm, EFM while tracking
A signal was recorded (linear velocity: 1.4 m / sec), reproduced with continuous light of the laser beam and a semiconductor laser with an oscillation wavelength of 635 nm and a beam diameter of 1.1 μm, and the reproduced waveform was observed. The results are shown in Table 3.

[0048]

[Table 3]

[0049]

The optical recording medium according to any one of claims 1 to 8 comprises a compound represented by the general formula (I) or at least one specific compound selected from the compounds in the recording layer. Therefore, since it has a high light absorption ability and a light reflectivity at a wavelength of 700 nm or less, it is possible to record and reproduce with a laser beam in a wavelength range of 700 nm or less, which enables high-density recording, and has light resistance. , Excellent in storage stability.

An optical recording medium according to claim 9 comprises at least one compound represented by the general formula (I) and 680 to 7
Since the recording layer contains an organic dye having a maximum absorption wavelength of 50 nm, it can be used as a CD-R in the current system, and even if it becomes a next-generation high-density optical disc system, recording is performed. It is possible to reproduce the information that has been recorded.

An optical recording medium according to claim 10 is 680-75.
As the organic dye having the maximum absorption wavelength at 0 nm, at least one of pentamethine cyanine dye, phthalocyanine dye and azo metal chelate dye is selected.
High quality signal characteristics can be recorded.

In the optical recording medium of the eleventh aspect, since the recording layer is recorded by the laser light having the wavelength of 630 to 720 nm, the optical recording medium is 1.6 to 1.8 times as large as the optical recording medium corresponding to 770 to 830 nm. A high density write-once write-once type optical recording medium is obtained.

In the optical recording medium of the twelfth aspect, since the reflecting layer is made of aluminum or gold, it is possible to realize a high reflectivity and a CD-R medium with good productivity.

In the optical information recording medium of the thirteenth aspect, since the protective layer is made of the ultraviolet curable resin, it is possible to form the protective layer medium having high productivity.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a layer structure as an ordinary write-once type optical recording medium applicable to the recording medium of the present invention.

FIG. 2 is a diagram showing an example of a layer structure for a CD-R that can be applied to the recording medium of the present invention.

FIG. 3 is a diagram showing another example of layer structure for a CD-R that can be applied to the recording medium of the present invention.

[Explanation of symbols]

1 substrate 2 Recording layer (organic dye layer) 3 subbing layer 4 protective layer 5 Hard coat layer 6 reflective layer 7 Protective board 8 Adhesive layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Noboru Sasa             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Yasunobu Ueno             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh (72) Inventor Yasuhiro Higashi             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F term (reference) 2H111 EA03 EA22 EA32 EA33 FA11                       FA12 FA14 FA23 FA30 FB42                       FB43 FB45                 5D029 JA04 JC17

Claims (13)

[Claims] 1. Recording on a substrate directly or through an undercoat layer
A layer is provided, and if necessary, a reflective layer and a protective layer are further provided thereon.
In an optical recording medium provided with
Contains at least one compound represented by general formula (I)
An optical recording medium characterized by the following. [Chemical 1] [In the formula, M, X¹~ X^FourAnd X^Five~ X⁸Are respectively
Represents something. M: 2 hydrogen atoms or oxygen atoms
Or divalent, trivalent or 4 which may have a halogen atom.
A valent metal atom, or a substituted or unsubstituted alkyl group,
Aryl group, alkoxy group, aryloxy group,-(O
PR¹R²) P group, (-OPOR³R^Four) P group,-(OSiR
^FiveR⁶R⁷) P group,-(OCOR⁸) P group,-(OR⁹) P group,
-(OCOCOOR^Ten) P group,-(OCOCOR)¹¹) P group
Or- (OCONR ¹²R¹³) Gold that may have p groups
Genus atom, R¹~ R¹³: Independently hydrogen atom, substitution
Or unsubstituted monovalent aliphatic hydrocarbon group or substituted or
Is an unsubstituted monovalent aromatic hydrocarbon group, X¹~ X^Four, X^Five~
X⁸: Independently hydrogen atom, halogen atom, cyano
Group, substituted or unsubstituted linear or branched alkyl
Groups, alkylalkoxy groups, substituted or unsubstituted
Coxy group, carboxylic acid ester group, substituted or unsubstituted
Aryl groups, substituted or unsubstituted aryloxy
Groups, substituted or unsubstituted alkylthio groups, substituted or
Is an unsubstituted arylthio group, a substituted or unsubstituted benzene
Zyl group, substituted or unsubstituted benzyloxy group, substituted
Or an unsubstituted benzylthio group or a heterocyclic residue. ] 2. In the general formula (I), X ^{1 to} X ⁴ are each independently a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, and X ^{5 to} X ⁸ are each independently a hydrogen atom. , An alkoxy group or a halogen atom (provided that X
The optical recording medium according to claim 1, wherein ^{1 to} X ⁸ are not all hydrogen atoms). 3. In the general formula (I), X ^{1 to} X ⁴ are each independently a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, and X ^{5 to} X ⁸ are each independently a hydrogen atom. The optical recording medium according to claim 1, which is a halogen atom (provided that not all X ^{1 to} X ⁸ are hydrogen atoms). 4. In the general formula (I), X ^{1 to} X ⁴ are each independently a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group, an alkylalkoxy group or an alkoxyl group, and X ^{5 to} X 4 ⁸ is a phenyl group having substituents Y ¹ and Y ² , and Y ¹ and Y ² are each independently a hydrogen atom, a linear or branched alkyl group optionally substituted with a halogen atom, an alkylalkoxy group, an alkoxyl group or The optical recording medium according to claim 1, which is an aryl group which may be substituted with a halogen atom. 5. The light according to claim 1, wherein in the general formula (I), X ^{1 to} X ⁴ are cyano groups, and X ^{5 to} X ⁸ are substituted or unsubstituted linear or branched alkyl groups. recoding media. 6. In the general formula (I), X ^{1 to} X ⁴ are cyano groups, and X ^{5 to} X ⁸ are substituents Z ^{1 to} Z ⁵ , Z ¹ ′ to Z ⁵ ′,
A phenyl group having Z ¹ ″ to Z ⁵ ″, Z ¹ ′ ″ to Z ⁵ ′ ″,
At least one of the substituents is a fluorine atom, a fluorine atom-containing alkyl group or an alkoxyl group.
The optical recording medium according to 1. 7. The optical recording medium according to claim 1, wherein in the general formula (I), X ^{1 to} X ⁴ are cyano groups and X ^{5 to} X ⁸ are substituted or unsubstituted aryl groups. 8. In the general formula (I), X ^{1 to} X ⁴ are each independently a hydrogen atom, a substituted or unsubstituted linear or branched alkyl group, and X ^{5 to} X ⁸ are hydrogen atoms or an alkyl group. The optical recording medium according to claim 1, which is a halogen atom. 9. The recording layer contains at least one compound represented by the general formula (I) and an organic dye having a maximum absorption wavelength at 680 nm to 750 nm. 8. The optical recording medium according to any one of 8. 10. The optical recording medium according to claim 9, wherein the organic dye having the maximum absorption wavelength at 680 nm to 750 nm is at least one of pentamethine cyanine dye, phthalocyanine dye and azo metal chelate dye. 11. The recording layer has a wavelength of 630 to 720 nm.
It is recorded by the laser beam of 1.
0. The optical recording medium according to 0. 12. The optical recording medium according to claim 1, wherein the reflective layer is made of aluminum or gold. 13. The optical recording medium according to claim 1, wherein the protective layer is made of an ultraviolet curable resin.